General Biology 2 Ilovepdf Compressed

The Commission on Higher Education in collaboration with the Philippine Normal University

Teaching Guide for Senior High School

GENERAL BIOLOGY 2 CORE SUBJECT This Teaching Guide was collaboratively developed and reviewed by educators from public and private schools, colleges, and universities. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the Commission on Higher Education, K to 12 Transition Program Management Unit - Senior High School Support Team at [email protected]. We value your feedback and recommendations.

Development Team Team Leader: Ivan Marcelo A. Duka

Writers: Neil Andrew B. Bascos, Ph.D., Ma. Genaleen Q. Diaz, Ph.D., Ian Kendrich C. Fontanilla, Ph.D., Ma. Carmina C. Manuel, Ph.D., Sharon Rose M. Tabugo, Ph.D., Eugenio P. Quijano Jr. Technical Editors:Annalee S. Hadsall, Ph.D. Copy Reader: Caroline H. Pajaron Published by the Commission on Higher Education, 2016 Illustrator: Ma. Daniella Louise F. Borrero Chairperson: Patricia B. Licuanan, Ph.D. Cover Artists: Paolo Kurtis N. Tan, Renan U. Ortiz Commission on Higher Education K to 12 Transition Program Management Unit Office Address: 4th Floor, Commission on Higher Education, Senior High School Support Team C.P. Garcia Ave., Diliman, Quezon City CHED K to 12 Transition Program Management Unit Telefax: (02) 441-0927 / E-mail Address: [email protected] Program Director: Karol Mark R. Yee Lead for Senior High School Support: Gerson M. Abesamis Consultants

Lead for Policy Advocacy and Communications: PROJECT WAS DEVELOPED WITH THE PHILIPPINE NORMAL UNIVERSITY. Averill M. Pizarro University President: Ester B. Ogena, Ph.D. Course Development Officers: VP for Academics: Ma. Antoinette C. Montealegre, Ph.D. VP for University Relations & Advancement: Rosemarievic V. Diaz, Ph.D. John Carlo P. Fernando, Danie Son D. Gonzalvo THIS

Ma. Cynthia Rose B. Bautista, Ph.D., CHED Bienvenido F. Nebres, S.J., Ph.D.,Ateneo de Manila University Carmela C. Oracion, Ph.D., Ateneo de Manila University Minella C. Alarcon, Ph.D., CHED

Teacher Training Officers: Ma. Theresa C. Carlos, Mylene E. Dones

Gareth Price, Sheffield Hallam University Stuart Bevins, Ph.D., Sheffield Hallam University

Administrative Officers: Ma. Leana Paula B. Bato, Kevin Ross D. Nera, Allison A. Danao, Ayhen Loisse B. Dalena

Monitoring and Evaluation Officer: Robert Adrian N. Daulat

Printed in the Philippines by EC-TEC Commercial, No. 32 St. Louis Compound 7, Baesa, Quezon City, [email protected]

This Teaching Guide by the Commission on Higher Education is licensed under a Creative Commons AttributionNonCommercial-ShareAlike 4.0 International License . This means you are free to: Share — copy and redistribute the material in any medium or format Adapt — remix, transform, and build upon the material. The licensor, CHED, cannot revoke these freedoms as long as you follow the license terms. However, under the following terms: Attribution— You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. NonCommercial— You may not use the material for commercial purposes. ShareAlike— If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the srcinal.

Table of Contents Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ii

Chapter 3: Systematics Based on Evolutionary Relationships

DepEd General Biology 2 Curriculum Guide . . . . . . . . . . . . . vi

Lesson 14:Systematics Based on Evolutionary Relationships:

Chapter 1: Genetics

Tree of Life and Systematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 09

Lesson 1:Pedigree Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Lesson 15:Systematics Based on Evolutionary Relationships:

Lesson 2:Sex Linkage and Recombination . . . . . . . . . . . . . . . .

8

Lesson 3:Modifications to Mendel’s Classic Ratios . . . . . . . . . 13 Lesson 4:Molecular Structure of DNA, RNA, and Proteins . . .

Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117 Lesson 16:Systematics Based on Evolutionary Relationships:

19

Cladistics and Phylogeny . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129

Lesson 5:DNA Replication and Protein Synthesis . . . . . . . . . .

24

Chapter 4: Compare and Contrast Processes in Plants and Animals

Lesson 6:Genetic Engineering . . . . . . . . . . . . . . . . . . . . . . . . .

30 36

Lesson 17:Reproduction and Development . . . . . . . . . . . . . . . . . 136

Lesson 8:History of Life on Earth . . . . . . . . . . . . . . . . . . . . . . .

49

Lesson 20:Transport and Circulation . . . . . . . . . . . . . . . . . . . . . . 190

Lesson 9:Mechanisms that Produce Change in Populations . .

70

Lesson 21:Regulation of Body Fluids . . . . . . . . . . . . . . . . . . . . . .

Lesson 7:Discuss the Applications of Recombinant DNA . . . . C h a p t e r 2 : E v o l u t i o n a n d Or i g i n o f B i o d i ve r s i t y

Lesson 18:Nutrition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158 L e s s o n 1Gas 9 : Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

194

Lesson 22:Immune Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204

Lesson 10:Evolution and Origin of Biodiversity: Patterns of

Descent with Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Lesson 23:Chemical and Nervous Control . . . . . . . . . . . . . . . . . 214

Lesson 11:Development of Evolutionary Thought . . . . . . . . .

Lesson 24:Sensory and Motor Mechanisms . . . . . . . . . . . . . . . . . 226

87

Lesson 12:Evidences of Evolution . . . .. . . . . . . . . . . . . . . . . . 92

Lesson 25:Feedback Mechanisms . . . . . . . . . . . . . . . . . . . . . . . .

Lesson 13:Infer Evolutionary Relationships of Organisms . . . . 102

Colored Images . . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . .

235 249

Biographical Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

i

Introduction As the Commission supports DepEd’s implementation of Senior High School (SHS), it upholds the vision and mission of the K to 12 program, stated in Section 2 of Republic Act 10533, or the Enhanced Basic Education Act of 2013, that “every graduate of basic education be an empowered individual, through a program rooted on...the competence to engage in work and be productive, the ability to coexist in fruitful harmony with local and global communities, the capability to engage in creative and critical thinking, and the capacity and willingness to transform others and oneself.” To accomplish this, the Commission partnered with the Philippine Normal University (PNU), the National Center for Teacher Education, to develop Teaching Guides for Courses of SHS. Together with PNU, this Teaching Guide was studied and reviewed by education and pedagogy experts, and was enhanced with appropriate methodologies and strategies. Furthermore, the Commission believes that teachers are the most important partners in attaining this goal. Incorporated in this Teaching Guide is a framework that will guide them in creating lessons and assessment tools, support them in facilitating activities and questions, and assist them towards deeper content areas and com etencies. Thus, the introduction of the SHS for SHS Framework.

SHS for SHS Framework

The SHS for SHS Framework, which stands for “Saysay-Husay-Sarili for Senior High School,” is at the core of this book. The lessons, which combine high-quality content with flexible elements to accommodate diversity of teachers and environments, promote these three fundamental concepts: SAYSAY:MEANING

Why is this important?

HUSAY: MASTERY

SARILI: OWNERSHIP How will I deeply understand this? What can I do with this?

Through this Teaching Guide, teachers will be able to facilitate an understanding of the value of the lessons, for each learner to fully engage in the content on both the cognitive and affective levels.

Given that developing mastery goes beyond memorization, teachers should also aim for deep understanding of the subject matter where they lead learners to analyze and synthesize knowledge.

When teachers empower learners to take ownership of their learning, they develop independence and selfdirection, learning about both the subject matter and themselves.

The Philippines is frequently cited as among the top countries most at risk to disasters. While disasters can arise from man-made sources, the most inevitable ones come from natural phenomena. Even without scientific scrutiny, every Filipino is familiar with the impacts of typhoons, earthquakes, volcanic eruptions, and fires to everyday life and to national development. This makes learning about disaster preparedness aligned with everyone’s interests. This teaching guide for the Disaster Readiness and Risk Reduction (DRRR) subject of the Philippines’ K-12 Curriculum provides a lesson-by-lesson framework for educators to help learners attain the target competencies and outcomes. The challenge with teaching a subject like DRRR is its multi-disciplinary nature, bringing together biological, geophysical, socio-cultural, political, and economic factors. This in itself is an opportunity to make these various subject matters relevant to the lives of the people even if studying disasters leans toward the sciences. With the use of these teaching guides, the teacher will be able to handle a diverse set of materials that will enrich their existing knowledge on the natural and social sciences. They will also be able to engage learners in a number of hands-on activities that make use of mixed-media to maximize existing resources. And overall, lessons tackled in these guides encourage a two-way interaction between the teachers and students that will ultimately result to effective learning.

About this Teaching Guide

Lessons of these teaching guides address the content standards identified by the Department of Education (DepEd). Some teaching guides may include multiple learning competencies as that may be more efficiently achieved when tackled together. This guide approaches learning about DRRR by first understanding the hazards that may then potentially lead to disasters, as a common confusion arises from distinguishing the concepts of “hazard and “disaster”. Each hazard type has its own precautionary measures and ideal responses to prevent disasters.Towards the end ofthe subject, learners will focus on applications to the community and the Philippine society. Users of these guides should note that sciences and policies related to DRRR are ever evolving along with improvements and breakthroughs in data collection and technology; so it is expected that reference materials also change through time. It would be important for teachers of the subject to continually update any cited references in each guide to make sure that the lessons will also result to cutting-edge teaching. As a big part of understanding disasters involves projecting future possibilities, the success of teaching the subject of Disaster Readiness and Risk Reduction may not be immediately measurable and definitely not something anyone is looking forward to test. But while the country is exposed to hazards that can alter the course of everyday life, bringing this subject to each classroom gives the people the power to take control of their lives and of nation-building in whatever the situation they may encounter in the future. iii

Parts of the Teaching Guide

This Teaching Guide is mapped and aligned to the DepEd SHS Curriculum, designed to be highly usable for teachers. It contains classroom activities and pedagogical notes, and is integrated with innovative pedagogies. All of these elements are presented in the following parts: 1. • • • • • 2. • • • • 3.

Introduction Highlight key concepts and identify the essential questions Show the big picture Connect and/or review prerequisite knowledge Clearly communicate learning competencies and objectives Motivate through applications and connections to real-life Mo tiva ti on Give local examples and applications Engage in a game or movement activity Provide a hands-on/laboratory activity Connect to a real-life problem Ins truction/Deliver y

• Give a demonstration/lecture/simulation/hands-on activity • Show step-by-step solutions to sample problems • Give applications of the theory • Connect to a real-life problem if applicable 4. Practice • Discuss worked-out examples • Provide easy-medium-hard questions • Give time for hands-on unguided classroom work and discovery • Use formative assessment to give feedback 5. Enrichment • Provide additional examples and applications • Introduce extensions or generalisations of concepts • Engage in reflection questions • Encourage analysis through higher order thinking prompts 6. Evaluation • Supply a diverse question bank for written work and exercises • Provide alternative formats for student work: written homework, journal, portfolio, group/individual projects, student-directed research project

On DepEd Functional Skills and CHED College Readiness Standards As Higher Education Institutions (HEIs) welcome the graduates of the Senior High School program, it is of paramount importance to align Functional Skills set by DepEd with the College Readiness Standards stated by CHED.

On the other hand, the Commission declared the College Readiness Standards that consist of the combination of knowledge, skills, and reflective thinking necessary to participate and succeed without remediation - in entry-level undergraduate courses in college.

The DepEd articulated a set of 21 st century skills that should be embedded in the SHS curriculum across various subjects and tracks. These skills are desired outcomes that K to 12 graduates should possess in order to proceed to either higher education, employment, entrepreneurship, or middle-level skills development.

The alignment of both standards, shown below, is also presented in this Teaching Guide - prepares Senior High School graduates to the revised college curriculum which will initially be implemented by AY 2018-2019.

C o l l e g e R e a d i n e s s S t a n d a rd s F o u n d a t i o n a l S k i l l s

D ep Ed F un c t i o n a l S k i l l s

Produce all forms of texts (written, oral, visual, digital) based on: 1. 2. 3. 4. 5.

Solid grounding onofPhilippine experience and and nation; culture; An understanding the self, community, Visual and information literacies, media literacy, critical thinking Application of critical and creative thinking and doing processes; and problem solving skills, creativity, initiative and self-direction Competency in formulating ideas/arguments logically, scientifically, and creatively; and Clear appreciation of one’s responsibility as a citizen of a multicultural Philippines and a diverse world;

Systematically apply knowledge, understanding, theory, and skills for the development of the self, local, and global communities using prior learning, inquiry, and experimentation

Global awareness, scientific and economic literacy, curiosity, critical thinking and problem solving skills, risk taking, flexibility and adaptability, initiative and self-direction

Work comfortably with relevant technologies and develop adaptations and innovations for significant use in local and global communities

Global awareness, media literacy, technological literacy, creativity, flexibility and adaptability, productivity and accountability

Communicate with local and global communities with proficiency, orally, in writing, and through new technologies of communication

Global awareness, multicultural literacy, collaboration and interpersonal skills, social and cross-cultural skills, leadership and responsibility

Interact meaningfully in a social setting and contribute to the fulfilment of individual and shared goals, respecting the fundamental humanity of all persons and the diversity of groups and communities

Media literacy, multicultural literacy, global awareness, collaboration and interpersonal skills, social and cross-cultural skills, leadership and responsibility, ethical, moral, and spiritual values

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General Biology 2

60 MINS

Lesson 1: Pedigree Analysis Content Standard

LESSON OUTLINE

The learners understand Mendel’s Laws of Inheritance. Performance Standard

Introduction Communicating Learning Objectives and

The learners shall be able to: •

make a Pedigree Analysis in the learner’s family using a simple genetic trait. Motivation

Learning Competency

5

Relevant Vocabulary Narrative

5

The learners shall be able to construct pedigrees and predict genotypes based on pedigree analysis (STEM_BIO11/12-IIIa-b-1)

Instruction

Recall in Mendelian Ratios, Discussion on Co-Dominance and Multiple Alleles

40

Specific Learning Outcomes:

Practice

Group Work: Non-Mendelian Traits in Humans, Plants, and Animals

40

At the end of the lesson, the learners will be able to: •

identify the mode of inheritance of a particular trait given the pedigree;

Materials

•

predict the genotypes of parents; and

Pen, paper, and ruler

•

compute the probability of occurrence of an affected offspring in a given cross.

Resources

(1) Klug WS, Cummings MR, Spencer CA, Palladino MA. 2012. Essentials of genetics. 8th ed. Benjamin Cummings; 2012. 624 p. (2) Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. 2012. Campbell biology, 9th ed. The Benjamin Cummings Publishing Co., Inc: 2012. 1464 p. (3) Bennett RL, Steinhaus KA, Uhrich SB, O’Sullivan CK, Resta RG, Lochner-Doyle D, Markel DS, Vincent V, Hamanishi J. Recommendations for standardized human pedigree nomenclature. Am J Human Genet. 1995; 56:745-752.

INTRODUCTION (5 MINS) 1. Cite the learning objectives, which are as follows: I. identify the mode of inheritance of a particular trait given the pedigree II. predict the genotypes of parents III. predict the probability of having an affected offspring 2. Relevant vocabulary I. Pedigree. Making use of diagrams showing the ancestral relationships and transmission of genetic traits over several generations in a family II. Proband. The individual in the pedigree that led to the construction of the pedigree. For example, a couple consults a medical geneticist because they have an offspring who is afflicted with a disease and they want to find out the mode of transmission of this disease. When the medical geneticist constructs the pedigree, the offspring will be labeled as the proband. Through the pedigree, the probability of having other affected children may be determined. III. Law of Segregation (1st Mendelian Law) . For every trait governed by a pair of alleles, these alleles segregate or separate during gamete formation in meiosis . A pair of alleles for one trait will IV. Law of Independent Assortment (2nd Mendelian Law) segregate or separate independently of another pair of alleles for another trait during meiosis A trait whose alleles that control it are found in the autosomes (body V. Autosomal trait. chromosomes/ non-sex chromosomes) VI. Genotype. The gene pair an individual carries for a particular trait symbolized with a pair of letters. By convention, uppercase letter (eg. A) for a dominant allele and lowercase letter (eg. a) for the recessive allele. Any letter in the alphabet may be used A. For a diploid organism with two alleles in a given gene pair, genotypes may be written as: i.

Homozygous dominant, i.e. with two dominant alleles (DD)

ii. Heterozygous, i.e. with a dominant and recessive allele (Dd). The individual will show the dominant phenotype. iii. Homozygous recessive, i.e. with two recessive alleles (dd) 2

Teacher Tip: Tell the learners that they have to use a letter in which the uppercase and lowercase versions are easy to distinguish using cursive to avoid confusion.

Ask learners to recall their lessons in classical genetics in their previous grade levels.

VII. Phenotype Teacher Tip: A. The observable trait of an individual based on its genotype. Examples: red flower, curlyNote that the phenotype is determined by the genotype. In complete dominance, RR- red flower; hair, blood types ( i.e. the blood type is the phenotype) B. For a typical Mendelian trait, phenotypes may either be: i.

Dominant. A trait that requires at least one dominant allele for the trait to be expressed, e.g. Dd

rr- white flower; but Rr will express the red flower condition because one dominant allele is enough for the dominant trait to be expressed in the organism.

ii. Recessive. A trait that requires two recessive alleles for the trait to be expressed VIII.Phenocopy. A trait that is expressed due to specific environmental conditions (i.e. having hair that is dyed of a different color) and is not due to the genotype. IX. Identical twins.Also known as monozygotic twins, which are derived from a single fertilization event. After the first cleavage or cell division of the zygote, the cells or blastomeres separate and become independent blastocysts implanted in the mother’s uterus. . Twins that are derived from separate fertilization events (two eggs X. Fraternal twins fertilized by two sperms) within the fallopian tube, resulting in two separate zygotes; also known as dizygotic twins Teacher Tip: REVIEW (15 MINS) The learners should be able to predict correctly 1. Ask the learners to recall Mendelian Laws of Inheritance the Mendelian ratios without having to use a (1Mendelian Law) I. Law of Segregation st Punnett square. They should be able to solve for probabilities of occurrence of a trait by analyzing a nd II. Law of Independent Assortment (2Mendelian Law) pedigree. 2. Ask the learners to define genotypes and phenotypes, dominant and recessive traits, homozygous and heterozygous dominants as well as homozygous recessive 3. Ask the learners to review the classic monohybrid Mendelian F2 genotypic and phenotypic ratios by filling out a table (see table 1 at the end of this document) 4. In a monohybrid cross and assuming complete dominance, the ratio of the F2 progenies may be predicted as 3:1, i.e. 3 with the dominant trait and 1 with the recessive trait. 5. In a dihybrid cross and assuming complete dominance, the ratio of the F2 progenies may be predicted as 9:3:3:1.

INSTRUCTION (15 MINS) 1. Define pedigree analysis. 2. Enumerate uses of pedigree analysis: I. Describe the mode of inheritance of a trait II. Calculate the probability of occurrence an affected offspring in a given cross 3. Establish symbols for creating pedigrees I. Male (square) vs female (circle) II. Affected (shaded) vs unaffected (unshaded) individual III. Marriage/mating line (line connecting mates) vs. sibship line (line connecting siblings) IV. Fraternal twins (one birthline branching out into the individual twin) vs. identical twins (same as fraternal twins but with a horizontal bar connecting the branches) V. Generation (Roman numerals) vs. individuals in the same generation, counting left to right (designated by HinduArabic numerals) VI. Proband (arrow)

4. What to expect in a human pedigree I. For autosomal dominant trait: Two affected individuals can have a normal offspring II. For autosomal recessive trait: Two affected individuals can NEVER have a normal offspring 5. Give an example of a pedigree and solve some questions

PRACTICE (25 MINUTES) 1. Divide learners into groups of four. 2. Provide copies of four sample pedigrees. (See samples in Figure 2 at the end of this document.) 3. For each pedigree, provide questions for the group to answer I.

Identify the mode of inheritance

II. Write down the genotypes of specific individuals III. Compute for the probability of having an affected offspring

Sample pedigree with symbol guides 4

A. Look at the family of IV-9 and IV-10. If the trait is dominant, is it possible for them to have an affected offspring? (Answer: NO. If the trait is dominant, then unaffected individuals are homozygous recessive. Two recessive individuals CANNOT produce a dominant offspring.) B. If the trait is recessive, is it also possible for IV-9 and IV-10 to have an unaffected offspring? (Answer: YES. This can happen if both parents are heterozygous for the trait, which means they can each give a recessive allele to produce a homozygous recessive offspring.) C. Based on your answers for a) and b), is the trait dominant or recessive? (Answer: RECESSIVE) D. Give the genotypes of the following: i. IV-9 (Answer: Dd) ii. IV-10 (Answer: Dd) iii. V-1 (Answer: DD or Dd) iv. I-1 (Answer: dd) v. I-2 (Answer: Dd) E. If IV-9 and IV-10 were to have another child, what is the probability that they will have an affected offspring? (Answer: 1/4 or 25% following the Mendelian ratio from a hybrid cross)

A. Is this trait dominant or recessive? (Answer: RECESSIVE. If the trait were dominant, then individuals I-3 and I-4 are both homozygous recessive, which means they CANNOT have a dominant offspring.) B. What are the most probable genotypes of I-3 and I-4? (Answer: Dd and Dd in order for each parent to be able to contribute a recessive allele to give rise to a recessive offspring.) C. What are the most probable genotypes of II-4 and II-5? (Answer: Dd and Dd. Same reason as b.) D. What is the probability that II-4 and II-5 will have another normal offspring? (Answer: 75%. A hybrid cross will produce 75% dominant offspring and 25% recessive offspring.)

A. Is the trait dominant or recessive? (Answer: DOMINANT. If the trait were recessive, then individuals I-1 and I-2 are homozygous recessive, and

A. Is the trait dominant or recessive? (Answer: DOMINANT. If the trait were recessive, then individuals I-3 and I-4 must be homozygous recessive, and

they CANNOT produce a dominant affected offspring.) B. What are the most probable genotypes of I-2 and I-3? (Answer: Dd and Dd. Each parent must be heterozygous in order to give a recessive allele to produce a recessive unaffected offspring.) C. What is the probability that II-2 is Dd? (Answer: 1 or 100%. II-2, together with the homozygous recessive II-1, was able to produce homozygous recessive unaffected offspring. This can only happen if II-2 also possesses a recessive allele, which means s/he is a heterozygote.) D. What is the probability that II-1 and II-2 will have another normal offspring? (Answer: 1/2 or 50%. Following the Mendelian cross of dd x Dd, there is a 50% probability of producing a homozygous recessive unaffected offspring.)

they produce a dominant B. What areCANNOT the genotypes of I-1 and I-2? offspring.) (Answer: dd and dd. Since the trait is dominant, it follows that unaffected individuals are homozygous recessive.) C. What is the probability that I-1 and I-2 will have an affected offspring? (Answer: 0. Homozygous recessive individuals CANNOT produce an offspring with a dominant trait.) D. What are the genotypes of I-3 and I-4? (Answer: Dd and Dd. Each parent must have a recessive allele in order to produce a homozygous recessive offspring.) E. What is the probability that II-6 is Dd? (Answer: 2/3. II-6’s parents are both heterozygotes. Following the Mendelian cross of Dd x Dd, the probabilities of occurrence of phenotypes in this cross are 25% (1/4) DD, 50% (2/4) Dd, and 25% (1/4) dd, giving a ratio of 1:2:1. Since II-6 is already affected, then his phenotype is dominant. Therefore, the probability of II-6 being affected is 0. So instead of a ratio of 1:2:1, the ratio to be considered should now be just 1:2 (DD:Dd). The probability of II-6 being Dd should now be 2/3.) 6

ENRICHMENT

1. As a homework, assign each learner to construct a pedigree of an authentic family using any of the following traits: I. With (dominant) or without finger hair (recessive) II. Normal (dominant) or hitchhiker’s thumb (recessive) III. Widow’s peak (dominant) or straight hairline (recessive) IV. Free (dominant) or attached earlobe (recessive) V. Curly (dominant), wavy (heterozygous) or straight (recessive) hair 2. B. Where possible, determine the genotypes of every individual in the family

CROS S

E XPE C T ED G EN O T Y P E( S )

E X P E CT E D P H E N O T YP E ( S )

DD

1. 2.

DD DD x DD Dd x

100% 50%

50% Dd

DD:

100% dominant 100% dominant

3.

DD dd x

100%

4.

Dd Dd x

25%

DD:

50% Dd: 25% dd

100% dominant 75% dominant: 25% recessive

5.

Dd dd x

50%

Dd:

50% dd

50% dominant: 50% recessive

Dd

General Biology 2

60 MINS

Lesson 2: Sex Linkage and Recombination Content Standard

LESSON OUTLINE

The learners understand inheritance of Sex Linked characters


Performance Standard

•

make a a research paper/case study/poster on transmission of a sex-linked genetic disease

Motivation

Case Study

10

Instruction

Discussion of Sex-Linked Traits

25

Learning Competency

Practice Group Work The learners shall be able to explain sex related inheritance and recombination; illustrate the transmission of sex-linked characters; and Enrichment Narrative distinguish sex-linked traits from other sex-related traits (STEM_BIO11/12-IIIab-2)

Materials

Specific Learning Outcomes

Pen, paper, and ruler

At the end of the lesson, the learners will be able to:

Resources

•

illustrate the transmission of an X-linked and a Y-linked character;

•

compute the probability of the occurrence of a sex-linked trait; and

•

give examples of other sex-related traits.

5

Relevant Vocabulary

The learners shall be able to

20

(1) Klug, W. S., M. R. Cummings, C. A. Spencer and M.A. Palladino. 2012. Essentials of Genetics. 8th ed. Benjamin Cummings. (2) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. 2012. Campbell Biology, (9th ed). The Benjamin Cummings Publishing Co., Inc. (3) Sheridan, M. 1999. Instructor’s guide for Biology, 5th ed. By Campbell, Reece, Mitchell. Addison Wesley Longman, Inc. 8

INTRODUCTION (5 MINS) Communicating Learning Objectives

1. Cite the learning objectives, which are as follows: I. illustrate the transmission of an X-linked and a Y-linked character II. compute the probability of the occurrence of a sex-linked trait III. give examples of other sex-related traits Relevant Vocabulary

2. State the relevant vocabulary: I. Sex linked trait. The gene (pair) that determines a character (e.g. hemophilia) is located on the sex chromosomes II. X-linked trait. A sex-linked trait is where the gene or allele for the trait is found on the X chromosome III. Color blindness. An X-linked recessive trait where a affected individual could not distinguish red from green color (red green color blindness) IV. Hemophilia. An X-linked recessive trait where an affected individual suffers from delayed blood clotting during injuries because of the absence of certain blood clotting factors V. Y-linked trait. A sex-linked trait where the gene or allele for the trait is found on the Y chromosome VI. Hypertrichosis pinnae auris. A Y-linked trait where affected males have hair growing from their external ears VII. Other sex-related traits. A. Sex-influenced trait- Any trait in a diploid organism whose expression is affected by an individual’s biological sex; a trait that occurs at a higher frequency in one sex over the other B. Sex-limited trait- Any trait in a diploid organism whose expression is limited to just one biological sex C.

Teacher tip: Ask the learners to review the topic on recombination in Meiosis that they took up in BIO 1. Recombination or shuffling of genes/ alleles in Meiosis results to variation in the genome of gametes, the sperm cells and egg cells. In any cell of the body (somatic), there are chromosome pairs. In humans, pair numbers 1-22 are the autosomes or body chromosomes while the last (23rd) pair is the sex chromosome. Normal human females have two X chromosomes and normal human males have one X chromosome and a Y chromosome; that is: XX- female XY- male

MOTIVATION (10 MINS) Case Study

Present these three cases using pictures:

A picture of a color blindness test chart Ask the learners if they could see a figure in the picture and ask the class to recite aloud the figure/ number.

A picture ofda family with male members breastfeeding A picture or descripti who are bal a baby on of a woman

Ask the learners if baldness occurs more in men or women.

Use a high resolution figure (photograph or image projected on a computer or LCD) to ensure the accuracy of the color blindness test. Those that could see the figure are normal; those that cannot are colorblind. In most cases, the colorblind males outnumber the colorblind females, which are rare. If there are no colorblind individuals in the class, the teacher will just have to mention as a matter of fact that colorblind females are rare.

Ask the learners who among the men and women are able to lactate or breastfeed their young.

Be careful in conducting this test to discourage teasing of actual colorblind learners. Emphasize that colorblind individuals are normal except that they could not distinguish between red and green colors. Misconception:Common misconception is that baldness occurs only in males. Emphasize that baldness does happen in women, although the frequency is much lower and is therefore rare.

10

INSTRUCTION (25 MINS) Sex-linked traits

• • • • • • • • • •

• • • • •

Give the definition of an X-linked trait Explain why X-linked traits may occur more frequently in one sex over the other In humans, males and females are represented by different sex chromosomes Females have two X chromosomes in the nucleus of their cells. Males have one X chromosome and one Y chromosome in the nucleus of their cells. Depending on whether the trait is dominant or recessive, the expression pattern of the trait differs in males and females Colorblindness in humans as an example of sex-linked trait The alleles responsible for colorblindness is found on the X chromosome only The dominant allele is the normal allele; the recessive allele causes colorblindness Females need two copies of the recessive allele, one from each of the two X chromosomes, for the trait to be manifested. If they only have one copy of the recessive allele, they have normal color vision. However, they are carriers for the trait in that they may pass it on to their offspring. Males only need one recessive allele in their sole X chromosome for the trait to be expressed. Explain what happens to the expression patterns if the trait is X-linked and dominant. Use Table 2 as guide. Give the definition of a Y-linked trait Explain why there is difference in expression between males and females for Y-linked traits. (Since the allele is found only in the Y chromosome, and since only males have Ychromosomes, then only males will express the trait. Females CANNOT express Y-linked traits.)

• •

Hypertrichosis pinnae auris as an example of a Y-linked trait If a male has the allele responsible for the trait, then his Y chromosome will possess that allele. Since he will pass on his Y chromosome to his sons, then all his sons will inherit the trait, and they, in turn, can pass on the allele to their sons.

3. Describe other sex-related traits Sex-influenced trait

• • • •

Give the definition Explain why traits may be expressed differently between sexes Hormonal or physiological differences between the sexes cause differences of expression of certain genes Baldness in humans as an example of a sex-influenced trait. See Table 1 how baldness is hypothesized to be expressed by a single pair of alleles, with B as the dominant allele for baldness and b as the recessive normal allele.

Sex-limited traits

• • • •

•

Give the definition Explain why traits may be limited to one sex only Hormonal or physiological differences between sexes may limit the expression of some genes to one biological sex only Functional mammary glands as an example of a sexlimited trait. Only females can express functional mammary glands that produce milk immediately after giving birth. Note that baldness behaves like a dominant trait in males in that only one dominant allele is needed for baldness to be expressed. On the other hand, the trait behaves like a recessive trait in women in that they need both dominant alleles to be present for baldness to be expressed.

PRACTICE (20 MINS) 1. Divide learners into groups of four. 2. Ask each group to answer a set of questions related to sex-related traits in humans. See sample questions.

ENRICHMENT As a homework, provide this narrative to the class: Teacher tip: The last Emperor of Russia, Nicolas II, was married to Empress Alexandra, and they had five Hemophilia is an X-linked recessive trait. Empress children, Olga, Tatiana, Maria, Anastasia, and Alexis. Alexis was the only one who was afflicted Alexandra was most likely a carrier of the trait (X CX). with hemophilia or the royal bleeding disease; all other members were normal. She was a descendant of Queen Victoria of the

•

Research on this medical condition and determine the mode of inheritance.

•

If only Prince Alexis was afflicted with the disease, determine his genotype.

• •

What could be the genotypes of the Emperor and Empress? Is it possible that each daughter could have been a carrier?

United Kingdom, who herself was a probable carrier. The Emperor was completely unaffected and therefore had an XY genotype. Based on the genotypes of the parents, Alexis had an X CY genotype, with the defective X chromosome carrying the allele for hemophilia coming from his mother. Each daughter, in turn, had a 50% probability of being a carrier, but they could NEVER have been affected.

12

General Biology 2

60 MINS

Lesson 3: Modification to Mendel’s Classic Ratios LESSON OUTLINE

Content Standard


The learners understand Non-Mendelian Modes of Inheritance Performance Standard

5

Relevant Vocabulary Motivation

Narrative

Instruction


40

The learners shall be able to describe some modifications to Mendel’s classic ratios (gene interactions) (STEM_BIO11/12-IIIa-b-3 )

Practice

Group Work: Non-Mendelian Traits in Humans, Plants, and Animals

40


Materials

5

The learners shall be able to •

make a research paper/case study/poster on a non-Mendelian genetic trait

Learning Competency


distinguish Mendelian from non-Mendelian modes of inheritance; and

•

describe some cases of non-Mendelian genetic traits

Pen and Paper Resources (1) Klug, W.S., Cummings, M.R., Spencer, C.A. and Palladino, M.A.. 2012. Essentials of Genetics. 8 th ed. Benjamin Cummings. (2) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. 2012. Campbell Biology, (9 th ed). The Benjamin Cummings Publishing Co., Inc. (3) Sheridan, M. 1999. Instructor’s guide for Biology, 5 th ed. By Campbell, Reece, Mitchell. Addison Wesley Longman, Inc.

INTRODUCTION (5 MINS)

MOTIVATION (5 MINS)

Communicating Learning Objectives

Narrative

1. Cite the major learning objectives, which are as follows:

1. Provide this narrative to the class:

I. distinguish Mendelian from non-Mendelian modes of inheritance

2. A local hospital has sent word to a family of a possible mix up of some of the children with other families when they were born. To rule out any possible mix up, the hospital obtained the blood types of every individual in the family, including the surviving maternal grandfather and paternal grandmother. The results were as follows:

II. describe some cases of non-Mendelian genetic traits Relevant Vocabulary

2. Present the following relevant vocabulary: Father: Type O Mother: Type A 1st child: Type O 2nd child: Type A

I. Co-dominance -When two contrasting alleles are present in the same locus or trait (heterozygote genotype), then the phenotype expressed is a “blend” of the two extreme phenotypes. The two genes interact and the offspring shows the effects of both alleles.

rd

3 child: Type B Maternal grandfather: Type AB Paternal grandmother: Type B

two contrasting alleles are II. Incomplete dominance When present in the same locus or trait (heterozygote genotype), then both alleles are expressed in the same phenotype

3. Based on the results, is there a possibility that any one of the children is not a biological offspring of the couple? To answer this question, we must first understand how blood types, a nonMendelian trait is inherited.

there are more than two types of III. Multiple alleles When alleles for a given locus or trait, this will result in more than two kinds of phenotypes that may be expressed for that trait.

14

INSTRUCTION (40 MINS)

Teacher Tip:


Review the Mendelian ratios and ensure that the learners are familiar with them before they could proceed with the lesson.

1. Let the learners recall the Mendelian Ratios in STEM_BIO11/12-IIIa-b-1 2. Discuss incomplete dominance. Define the trait. The heterozygote genotype is expressed as a distinct phenotype (a “blend” of the two extreme phenotypes). In this case, the phenotypic ratio is the same as the genotypic ratio I. Use snapdragon plants ( Antirrhinum majus) as example (see figure 1). A. RR – red flowers B. Rr – pink flowers C. rr – white flowers 3. Discuss co-dominance. Define the trait. The heterozygote genotype is expressed as a distinct phenotype (both extreme phenotypes are expressed at the same time). Similar to incomplete dominance, the phenotypic ratio is the same as the genotypic ratio. I. Use human MN blood typing as an example A. MM – type M B. MN – type MN C. NN – type N 4. Discuss multiple alleles. Define the trait. There are more than two types of alleles, and the relationship of each allele with respect to others will determine the number of phenotypes that may be expressed. I. Use coat color in rabbits as example (see figure 2) A. There are four different types of alleles in rabbits: C (Agouti), C ch (Chinchilla), Ch (Himalayan), and c (Albino), with the following dominance hierarchy: C> Cch>Ch> c. B. The following genotypes will have the corresponding phenotypes in coat color: i. CC – Agouti ii. CCch – Agouti iii. CCh – Agouti iv. Cc – Agouti v. CchCch – Chinchilla

Emphasize that incomplete dominance and codominance are similar in that their phenotypic ratios follow their g enotypic ratios. However, they differ in the expression of the heterozygote condition: in co-dominance, the heterozygote expresses both extreme phenotypes; in incomplete dominance, the heterozygote is expressed as a “blend” of the two extreme phenotypes.

vi.

CchCh

vii.

Cchc

– Chinchilla

Teacher Tip: Note that in the ABO system, the O allele is recessive to both A and B alleles while the A and B alleles are co-dominants of one another.

– Chinchilla

viii. ChCh – Himalayan ix. Chc – Himalayan x. Cc – Albino C. Use ABO blood typing in humans as example i. There are three different types of alleles A (or I A), B (or IB) and O (or i) ii. The following genotypes will have the following blood types (phenotypes): iii. AA (or IAIA) – Type A iv.

AO

(or IAi) – Type A

v.

BB

(or IBIB) – Type B

vi.

BO

(or IBi) – Type B

vii. AB (IAIB) – Type AB viii. OO (ii) – Type O 5. Go back to the Motivation narrative I. The class will now answer the question/narrative provided during the Motivation part. The teacher will ask first the most probable genotypes of all the members of the family as follows: i.

Father: Type O -OO

ii. Mother: Type A - AO iii. 1st child: Type O - OO iv. 2nd child: Type A - AO v. 3rd child: Type B – B? vi. Maternal grandfather: Type AB -AB

Blood types O and AB can only have OO and AB genotypes, respectively. The mother must be AO in order to have an offspring that is either A or O. The paternal grandmother must be BO in order to have an offspring (father) who is blood type O. The 3rd child could have been the result of a mix up because the B allele is not present in either parent.

Misconception Emphasize that blood typing could only be used to exclude/disprove biological parentage, not to prove it.

vii. Paternal grandmother: Type B –BO viii. Possible mix-up? Yes, 3rd child. 16

PRACTICE (40 MINS) 1. Divide learners into groups of four. 2. Ask each group to answer a set of questions related to nonMendelian modes of inheritance. See sample questions. 1. In cattle, coat color is inherited in a co-dominant fashion. Homozygous B1B1 produces black coat, homozygousB2B2 produces white coat, and the heterozygous B1B2 produces roan coat. Give the phenotypic ratio of the offspring of the following crosses: A.

B1B1 x B1B1

(ANSWER: all black)

B.

B1B1 x B2B2

(ANSWER: all roan)

C.

B B x B B

(ANSWER: 25% Black: 50% Roan: 25% White)

D.

B1B1 x B1B2

(ANSWER: 50% Black: 50% Roan)

1

E.

1

2

2

1

2

C. Two wavy plants will produce what possible kinds of offspring? Give their ratios? (ANSWER: 25% serrated: 50% wavy: 25% smooth; this is a hybrid cross, which will give a 1:2:1 ratio) 3. In guinea pigs, coat color is governed by four alleles that constitute a multiple allelic series, C (black), cS (sepia), cC (cream), and c (albino) with the following dominance hierarchy: C>cS>cC>c. Determine the phenotypic ratios of the progeny from the following crosses: A. Cc x CcS (ANSWER: 75% black: 25% sepia; the genotypes and their probabilities of occurrence are: 25%

2

2

B B xB B

S

(ANSWER: 50% Roan: 50% White)

2. In a hypothetical plant, a serrated leaf margined plant, when crossed with a smooth leaf margined plant, produces offsprings with wavy leaf margin. A. Identify the mode of inheritance. (ANSWER: Incomplete dominance) B. Two serrated plants, when crossed, will give what type of offspring? (ANSWER: Serrated plants; the trait is homozygous, therefore producing offspring with the same phenotype as the parents)

S

CC,

25% Cc , 25% Cc, and 25% c c, giving a phenotypic ratio of 75% black and 25% sepia) B. CcS x cCc (ANSWER: 50% black: 50% sepia; the genotypes and their probabilities of occurrence are 25% CcC, 25% Cc, 25% cScC, 25% cSc, giving a phenotypic ratio of 50% black and 50% sepia) 4. A man who is blood type B is married to a woman who is blood type A. None of the man’s parents is blood type O. This couple has 4 children with the following blood types: B, AB, AB and O. Give the genotypes of the parents. (ANSWER: Man: BO; Woman: AO; Both parents must have an O allele in order to produce and offspring with blood type O with genotype OO)

Incomplete dominance in snapdragons, Antirrhinum majus. The cross involving homozygote red flowers (RR) and homozygote white flowers (rr) will yield a heterozygote (Rr) that expresses a different phenotype, which is pink flowers. The cross between pink-flowered individuals will produce offsprings where the genotypic ratio also becomes the phenotypic ratio (25% red: 50% pink: 25% white). (Wikipedia)

Coat color in rabbits. The trait is controlled b multiple alleles with the following dominance hierarchy: C (Agouti) > Cch (Chinchilla) > Ch (Himalayan) > c (Albino).

18

General Biology 2

60 MINS

Lesson 4: Molecular Structure of DNA, RNA, and Proteins Content Standard

LESSON OUTLINE

The learners understand Structures and Functions of DNA, RNA and proteins Performance Standard


build models of DNA, RNA and proteins

Introduction Communicating Learning Objectives

5

Motivation

Group Work

5

Instruction

Discussion on the Molecular Structures of DNA, RNA, and Proteins

Practice

Building Models of DNA

Enrichment

Conversion to mRNA Transcripts

Evaluation

Identification of Biomolecule Represented by Given Chain Structures

Learning Competency

The learners shall explain how the structures of DNA, RNA and proteins are related to their functions (STEM_BIO11/12- IIIa-b-4) Specific Learning Outcomes


describe the building blocks of DNA, RNA and proteins;

•

identify the structural and functional differences between DNA and RNA and

•

explain the different levels of protein structure

Materials

Recyclable materials for model construction; freely downloadable molecular modeling software. Resources

Biochemistry textbooks; SwissPDB Viewer software (free download); Protein Data Bank (www.pdb.org)

30 5 5 10


Teacher Tip:


One dimensional and two dimensional models of DNA should be presented to the class.

1. The learning outcomes will be presented as follows: I. describe building blocks of DNA, RNA and Proteins. II. identify the structural and functional differences between DNA and RNA.

III. discuss the different levels of protein structure (primary, secondary, tertiary and quaternary) IV. 4.explain how protein structural features may influence their functions 2. Ask learners if they have heard of the term “genes”. Ask them what “genes” have they inherited from their parents. Sample answers: genes for dimples, straight hair, etc.

MOTIVATION (5 MINS)

Teacher Tip:

1. Divide the class into groups of learners. Allow each group to enumerate the most important functions of DNA and proteins that they can recall from their previous grade levels. 2. Consolidate these answers on the board.

INSTRUCTION (30 MINS) 1. The building blocks of any nucleic acid are the nucleotides. 2. A nucleotide is composed of a phosphate group (with negative charges), a sugar portion and an N-base. 3. The sugar in DNA is deoxyribose while the sugar in RNA is ribose. Explain the difference through a visual aid. 4. DNA and RNA are polynucleotides. N-bases are either purines or pyrimidines. Purine bases are Adenine (A) and Guanine (G). Pyrimidines are Cytosine (C), Thymine (T, in DNA only) and Uracil (U, found only in RNA) 5. Specific base pairings occur in DNA. A pairs with T; G pairs with C 6. DNA is double stranded while RNA is single stranded with Uracil instead of Thymine. 20

Expected Answers: DNA: repository of genetic i nformation RNA: transcripts; link between the gene and the gene product (protein) Protein: functional products; executors of cellular functions

7. Main Functions: I. DNA: repository of genetic information; sequence of bases encodes the blueprint for life processes II. RNA: information in the form of base sequence is transformed (transcribed) into mRNA, tRNA and rRNA. DNA is the template copied into RNA by base pairing. G with C; A with U. III. Protein: functional products of genes; executes cellular functions 8. The four structural levels of proteins are: 1.Primary- sequence of amino acids in the polypeptide chain; 2. Secondary- when the polypeptide chains form a helix or a pleated sheet structure; 3. Tertiary- coiling of the polypeptide, combining helices and sheet forms; 4. Quaternary- the association of two or more polypeptides in space

Teacher Tip: If computers and internet facilities are available, structures for these biomolecules are available as molecular structure files (*.pdb) from the Protein Data Bank (www.pdb.org).Focus on the important parts of the structure that provide the necessary physical properties of DNA, RNA and proteins. Discuss the importance of these p hysical features for the functions of DNA, RNA and proteins.

Summary of Important Physical Properties B IOM OL E C U L E

P hys ic a l P roper ty

F unctio na l R eleva nc e

DNA

RNA

PROTEIN

Complementary Base Pairs

Allows each strand serve as a template for replication and to transcription

Phosphodiester bonds

Essential for polynucleotide chain elongation

Emphasize that the DNA has negative charges on the outside due to the phosphate groups. Other stabilizing factors in the DNA should be mentioned.

Single stranded but some bases For stability can be complementary; hence, some portions may be double stranded Uracil

NitrogenousbasefoundonlyinRNA.

Amino (N)Terminus

Start of the polypeptide chain

Amino (N)Terminus

End of the polypeptide chain

PeptideBond

Linksaminoacidstogether

One letter symbol for each amino acid

Classes: a. non-polar- aliphaticor aromatic b. polar, uncharged c. polar, charged- acidic and basic

Note: For each classification of amino acid,give the names of each amino acid. Give the one letter symbol for each amino acid. The three letter code for each amino acid may also be provided.

PRACTICE (5 MINS) Given the following coding sequence for DNA, provide the sequence of the complementary (template) sequence. Coding sequence :

5’ ATGCATAGATTAGGATATCCCAGATAG 3’

(Answer) Complementary sequence

Teacher Tip: Be sure to note the antiparallel orientation of the coding and non-coding strands of DNA. Explain the relative positions of the 5’ and 3’ ends.

3’ TACGTATCTAATCCTATAGGGTCTATC 5’

Ask the learners to build models of DNA by using recyclable materials such as popsicle sticks or pieces of colored papers to represent the complementary bases: G with C; A with T. The DNA backbone (phosphate, sugar) should be included.

ENRICHMENT (5 MINS) 1. Convert the given coding sequence into an mRNA transcript: Complementary Non-coding/ Template sequence 3’ TACGTATCTAATCCTATAGGGTCTATC 5’ (Answer) Coding sequence ~ mRNA transcript

5’ AUGCAUAGAUUAGGAUAUCCCAGAUAG3’

5’ AUGCAUAGAUUAGGAUAUCCCAGAUAG3’

(Answer) Polypeptide sequence

The mRNA transcript has almost the same sequence as the coding sequence (DNA), but the thymines are replaced to Uracil. Show the learners how to read the codon Table Teach the learners the single letter codes for the amino acids (e.g. ryptophan ! Trp ! W).

2. Translate the given mRNA transcript into a polypeptide sequence: Coding sequence ~ mRNA transcript

Teacher Tip:

N-Met-His-Arg-Leu-Gly-Tyr-Pro-Arg-C

22

Ask the learners to spell their names using the amino acid codes (e.g. N-E-I-L ! Asn – Glu – Ile – Lue).

EVALUATION (10 MINS) Ask learners to identify the type of biomolecule represented by a given chain structure: 1. DNA2. RNA3. ProteinExample Template sequence

3’ TAC_ _ _TCT_ _ _ CCTATAGGGTCT 5’ 5’ _ _ _CAUAGAUUA_ _ _UAU_ _ _AGA 3’ Learners may be asked to identify the important structural features in these chain structures (features are listed in the instruction/ delivery table). A similar exercise of generating non-coding sequences (DNA), transcripts (RNA) and translated polypeptides may be done to test the learners understanding of the topic.

Teacher Tip: To help learners practice t he generation of complementary sequences, worksheets with partially completed sequences may be used.

General Biology 2

60 MINS

Lesson 5: DNA Replication and Protein Synthesis LESSON OUTLINE

Content Standard


The learners understand Central Dogma of Molecular Biology. Performance Standard


5

Review

identify requirements, enzymes and products in DNA Replication, transcription, and protein synthesis.

Motivation

Inquiry

Instruction

Discussion on DNA Replication or DNA Synthesis

20

Matching Type Game Take-home Activity

10 5

Learning Competency

Practice

The learners should be able to diagram the steps in DNA replication, transcription, and protein synthesis (STEM_BIO11/12- IIIa-b-5)

Evaluation

5

Materials Specific Learning Outcomes

Paper, coloured pens


Resources

•

describe the requirements, proteins and enzymes in DNA replication;

•

transcription and translation; and

•

diagram the steps in replication, transcription and translation.

24

(1) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. 2012. Campbell Biology, (9 th ed). The Benjamin Cummings Publishing Co., Inc.

INTRODUCTION (5 MINS) 1. The learning objectives will be communicated as follows: A. Describe the requirements, proteins and enzymes in DNA replication, transcription and translation B. Diagram the steps in replication, transcription and translation. C. Explain what happens to a gene sequence that undergoes transcription and eventual translation into protein 2. Ask the learners to recall the significance of Mitosis. Mitosis is an equational cell division that produces daughter cells which are identical or clones of the srcinal, mother cell. This ensures that every cell of the body has the same genetic content, i.e. chromosome number. To make this possible, cells have to duplicate their genetic material which is primarily DNA.

MOTIVATION (5 MINS) 1. Ask learners to imagine how many cells a typical mature human contains. Tell them that they all came from just one fertilized egg cell. A zygote goes through millions of generations of cell divisions to become just the one person that a learner is. Even until now, cells in an individual are still dividing. Ask learners what examples of tissues in their body are undergoing cell division. (sample answers: skin; blood cells) 2. Also, ask learners to recall that in the previous topics on genetics, the phenotype is the outside, visible characteristic of an organism. Any phenotype (eg. red flower) is directly determined by proteins or enzymes functioning in a metabolic pathway. Proteins are made by “turning on” specific portions of DNA that are called genes. Particular sequences of DNA are transcribed to become RNAs. These are then used to produce proteins in a process called translation.


INSTRUCTION (65 MINS) DNA strands separate and serve as templates for the 1. DNA replication or DNA synthesis. production of new DNA molecules. A. The following are features of replication: i. Semiconservative- the resulting DNA consists of one old and one new strand ii. Base pairing is maintained; Adenine pairs with Thymine, Guanine pairs with Cytosine iii. New DNA molecules are produced in the 5’ to 3’ direction iv. Semidiscontinuous. The leading strand is synthesized in a continuous manner (5’ to 3’) while the lagging strand is produced discontinuously in short stretches called Okazaki fragments. B. In lagging strand synthesis, there is a need for a primer terminus which is provided by an RNA molecule. RNA is synthesized by a primase or RNA polymerase. The 3’OH of the RNA is where new DNA nucleotides are added thus new DNA is built in the 5’ to 3’ direction. C. Enzymes in replication are as follows: 1. helicase; 2. gyrase; 3. SSB (single strand binding proteins); 4. primase or RNA polymerase; 4. DNA polymerase and 5. DNA ligase.

26


. DNA is unwound and one strand is used as template for the 2. Transcription or RNA synthesis production of an RNA molecule. An RNA polymerase makes RNA in the 5’ to 3’ direction. Specific regions in the DNA called promoters allow the binding of transcription factors which make possible the binding of RNA polymerase. Three major types of RNA are: messenger RNA (mRNA); transfer RNA (tRNA) and ribosomal RNA (rRNA).

. This occurs in the ribosome. Basic ingredients are the 3. Translation or protein synthesis various types of RNAs produced in transcription and some proteins or enzymes. The mRNA contains triplets of bases called codons that specify an amino acid, eg. UUU-phe. Various tRNAs carry amino acids from the cytoplasm to the actual site of translation in the ribosome. A tRNA has an anticodon that pair with a codon in the mRNA. Different rRNAs combine with ribosomal proteins to make up the subunits of a ribosome. A functional ribosome has a small and a large subunit. In bacteria, transcription and translation may be simultaneous. In eukaryotic cells, mRNA, tRNA and rRNA travel from the nucleus to the cytoplasm through the nuclear pores. RNAs may undergo processing. Some unnecessary parts like introns are removed. In eukaryotic mRNA, a 5’ cap and a 3’ poly A tail are added. Coding regions of mRNA are called exons. They specify functional protein products.


In the elongation process of translation, amino acids are linked by peptide bond formation due to the action of peptidyl transferase known to be a part of the ribosome subunit. The process is summarized in the diagram above.

To initiate translation, the small and the big subunits of the ribosome have to be separated. Initiation factors (IF) make this possible. They also prevent the premature reassociation of these subunits. The small subunit of the ribosome binds the mRNA and allows the entrance of a tRNA to the P site bearing the first amino acid. The big subunit then binds and together they form an assembly ready for the next amino acid in the A site of the ribosome. A stop codon signals the end of translation. No amino acid corresponds to a stop codon. Release factors halt the process and the polypeptide is released. The genetic code is the correspondence of the mRNA codons to amino acids. An amino acid is specified by a codon with three code letters. The genetic code is shown as above.

28

The genetic code is the correspondence of the mRNA codons to amino acids. An amino acid is specified by a codon with three code letters. The genetic code is shown as follows:

Teacher Tip: Use flash cards. Organize learners into groups and ask them to compete.

Point out the effect of the loss of the following:

PRACTICE (5 MINS) 1. Matching Type Game: For each protein or enzyme or structure mentioned above, identify whether such is involved in replication, transcription or translation. 2. Explain why both DNA replication and RNA transcription are disrupted by the loss of RNA polymerase. EVALUATION (5 MINS) 1. As an assignment, ask the learners to make their own diagram of the steps involved in DNA replication, transcription and translation or protein synthesis. (Note: The learners may choose a

E N Z YM E

E F FE C T O F L O SS

DNA Polymerase

No replication

Helicases

Decreased DNA replication efficiency

Peptidyl transferase

No peptide bond formation

RNA Polymerase

No replication No transcription

Ribosomes

Not ranslation

variety of medium for presenting the steps of the processes.)

General Biology 2

60 MINS

Lesson 6: Genetic Engineering Content Standard LESSON OUTLINE

The learners outline the steps in Recombinant DNA. Performance Standard



5

Review

• explain how genes may be modified and/or inserted in host cells/ organisms.

Motivation

Desirable Traits

Learning Competency

Instruction

GeneticEngineering

The learners should be able to outline the steps involved in genetic engineering (STEM_BIO11/12-III a-b-6)

Practice

Recitation

5

Enrichment

Poster Making

5

Evaluation

Assignment

5


5 35

At the end of the lesson, the learners will be able to: Materials

•

compare classical breeding with modern genetic engineering techniques;

•

enumerate the steps in molecular cloning;

Recyclable materials for paper models of plasmids; scissors; tape; pens of various colors

•

describe some methods to introduce DNA into cells; and

Resources

•

explain the selection and screening of transformants / genetically modified organisms (GMOs)

Biochemistry textbooks; online videos on genetic engineering and GMOs

30

INTRODUCTION (5 MINS) Communicating Learning Objectives and Review

Teacher Tip:

1. The learning outcomes will be presented and the overall idea on how organisms may be modified will be discussed.

Make a quick review of the previous lesson on DNA replication and protein synthesis.

2. In order to survive, man has successfully domesticated selected plants and animals. He has taken an active part in choosing desired traits of plants and animals. Traits that were considered valuable (i.e. high fruit yield; high milk production, etc.) were sought out and propagated. The processes involved may include classical breeding practices such as controlled pollination of plants, and the mating of animals with desired traits. In today’s modern science, molecular biology techniques are being employed in the insertion and expression of proteins in different organisms for various purposes.

MOTIVATION (5 MINS) Teacher Tip: Desirable Traits

1. Ask for volunteers to enumerate plants and animals that have desirable or enhanced traits. 2. Ask learners to explain how each of the traits was introduced or developed (i.e. classical breeding or recombinant DNA technology). E N H A N C E DT R A IT

M O D I F Y I N GT E C H N I Q U E

Kobe / Wagyu Beef (Beef with good fat distribution)

Classical breeding

Guapple (Large sized guava) Human Insulin-producing bacteria Flavr-Savr (Delayed-ripening tomatoes) Macapuno trait in coconuts

Classical breeding Recombinant DNA Technology Recombinant DNA Technology Classical breeding

Group the learners into 3’s or 4’s and allow each group to discuss examples of “enhanced” animals/ plants.


Teacher Tip:

Genetic Engineering

Pictures of common domesticated plants and animals may be shown in class.

1. Classical breeding practices focus on the mating of organisms with desirable qualities. 2. Genetic engineering involves the use of molecular techniques to modify the traits of a target organism. The modification of traits may involve: I. introduction of new traits into an organism II. enhancement of a present trait by increasing the expression of the desired gene III. enhancement of a present trait by disrupting the inhibition of the desired genes’ expression. 3. A general outline of recombinant DNA may be given as follows: I. cutting or cleavage of DNA by restriction enzymes (REs) II. selection of an appropriate vector or vehicle which would propagate the recombinant DNA ( eg. circular plasmid in bacteria with a foreign gene of interest) III. ligation together) of the gene of interest (eg. from animal) with the vector ( cut bacterial(join plasmid) IV. transfer of the recombinant plasmid into a host cell (that would carry out replication to make huge copies of the recombined plasmid) V. selection process to screen which cells actually contain the gene of interest VI. sequencing of the gene to find out the primary structure of the protein 4. After outlining the key steps in recombinant DNA, the teacher can proceed to describe the ways in which these plasmids may be introduced into host organisms. Biolistics. In this technique, a “gene gun” is used to fire DNA-coated pellets on plant tissues. Cells that survive the bombardment, and are able to take up the expression plasmid coated pellets and acquire the ability to express the designed protein. Plasmid insertion by Heat Shock Treatment. Heat Shock Treatment is a process used to transfer plasmid DNA into bacteria. The target cells are pre-treated before the procedure to increase the pore sizes of their plasma membranes. This pretreatment (usually with CaCl2) is said to make the cells “competent” for accepting the plasmid DNA. After the cells are made 32

High cost of medicine and other agricultural products may be mentioned.

competent, they are incubated with the desired plasmid at about 4 C for about 30min. The plasmids concentrate near the cells during this time. Afterwards, a “Heat Shock” is done on the plasmid-cell solution by incubating it at 42 C for 1 minute then back to 4 C for 2 minutes. The rapid rise and drop of temperature is believed to increase and decrease the pore sizes in the membrane. The plasmid DNA near the membrane surface are taken into the cells by this process. The cells that took up the plasmids acquire new traits and are said to be “transformed”. !

!

!

Electroporation. This technique follows a similar methodology as Heat Shock Treatment, but, the expansion of the membrane pores is done through an electric “shock”. This method is commonly used for insertion of genes into mammalian cells.

5. Some methods to screen recombinant cells are as follows: Selection of plasmid DNA containing cells

A selection marker within an theantibiotic inserted resistance plasmid DNA sequence allows the selection of gene) is “transformants”. Usually, gene (e.g. AMP ampicillin resistance included in the plasmid DNA. This allows only “transformed” cells to survive in the presence of the antibiotic (e.g. ampicillin). Plating the plasmid-cell solution on antibiotic-containing media will select for these “transformants” and only allow plasmid-containing cells to grow and propagate into colonies. Selection of transformed cells with the desired gene

Certain inserted genes within the plasmids provide visible proof of their presence. These include the antibiotic resistance genes that allow for the selection of the transformed cells within the solution. Some inserted genes also produce colored (e.g. chromogenic proteins) or fluorescent products (e.g. GFP) that label the colonies/cells with the inserted gene. In some cases, the location of the cloning site within the plasmid is in the middle of a gene (i.e. !-galactosidase, lacZ) that generates a (blue) colored product in the presence of a substrate (i.e. isopropyl !-D-1 thiogalactopyranoside, or IPTG). Cells transformed with these “empty” plasmids will turn blue in the presence of IPTG. Insertion of a gene in the cloning site disrupts the sequence of the !-galactosidase gene and prevents the generation of the colored

Teacher Tip: Agarose gel electrophoresis (AGE) allows the identification of PCR products and estimation of their sizes. This is done by running a molecular weight (MW) ladder alongside the samples. The MW ladder is made up of DNA fragments of known size (e.g. 100bp, 200bp, 300bp, 500bp, etc). The size of the PCR product may be approximated by the DNA fragment in the MW ladder that runs a similar distance.

product in the presence of the substrate. Cells transformed with the disrupted !-galactosidase gene will remain “white” in the presence of IPTG. This “blue-white screening” protocol is thus able to screen for cells that were transformed with the desired gene in the cloning site.

PCR detection of plasmid DNA

Alternatively, the presence of the desired gene in the inserted plasmids may be confirmed using PCR amplification. PCR reactions specific for the desired gene may be done using DNA from cells. Amplification of the expected product would confirm the presence of the gene within the samples. PCR reactions specific for plasmid sequences will also confirm/identify the type of plasmid used for the transformation. Genetically Modified Organisms (GMOs)

With the ability to insert gene sequences, comes the possibility of providing new traits for these target organisms. This has allowed the development of GMOs. Some of these genetic modifications promise higher product yield for their targets. These include the Flavr-Savr Tomato and Bt-Corn. The Flavr-Savr(“Flavor Savor”) tomato was the first genetically modified organism that was licensed for human consumption. The trait modified in this tomato is its ripening process. A gene for an enzyme that causes the degradation of pectin in the cell walls (i.e. polygalacturonase) normally softens the fruit as it ripens. In Flavr Savr tomatoes, an inhibitor (i.e. antisense RNA) disrupts the expression of this gene, thereby delaying the softening of the fruit and extending the time it may be kept in storage and transported to markets. Bt-Cornwas developed to incorporate the production of a toxin (i.e. Bt-endotoxin) from Bacillus thuringensis in corn plants. This toxin results in the death of pests that feed on these plants like the corn borer larvae. The toxin has been shown to be selective for Lepidoptera larvae and is non-toxic to humans, mammals, fish and birds. The selective toxicity of the toxin allows its use in foodcrops. The introduction of the toxin is believed to increase crop production due to decreased losses from pest infestation. The same technology has been applied in the Philippines for the development of Bt-Eggplant. 34

Teacher Tip: Note that antisense RNA strands bind to mRNAs. This prevents their expression into proteins.

Note: Which of the techniques discussed can be used to detect if GMOs were used in a certain food product? Answer: Assuming that the DNA is still intact in the sample, testing for specific marker genes in expression plasmids can be used to detect the presence of these engineered plasmids.

Despite the proposed benefits of GMOs, some people have raised their concerns regarding the consumption of these modified foods. While most of the products are tested for safety, concerns are raised for the possibility of not being able to detect hazards that are present, but are currently undetectable by today’s current technology. Because of these issues, manufacturers are urged to provide labels that notify consumers of GMO presence in their products. While GMOs are believed to be safe when licensed by the food regulatory agencies, it is believed that the consumers must be provided with enough information to make their own choices regarding their use.

PRACTICE (5 MINS) Recitation

1. Ask the learners to differentiate the various technologies for delivering genes into cells. 2. Determine which technologies are most appropriate for which cell types.

Teacher Tip: Biolistics may be more suitable for plants due to their thick cell walls.

(Answers: Biolistics for plants; Electroporation for mammalian cells; Heat shock for bacterial cells)

ENRICHMENT (5 MINS) Poster Making

1. Learners may be asked to make a poster on the steps and other methods involved in recombinant DNA.

EVALUATION (5 MINS) Assignment

1. Give an assignment and allow learners to research on the pros and cons of genetic engineering. 2. Ask them for their opinion on the matter, and ask them to support these opinions with facts learned in class. Be sure that issues of biosafety are included in the discussion.

Teacher Tip: This may also be given as an assignment.

General Biology 2

60 MINS

Lesson 7: Discuss the Applications of Recombinant DNA Content Standard LESSON OUTLINE

The learners demonstrate an understanding of recombinant DNA and examples of products from Recombinant DNA Technology. Performance Standards

The learners shall be able to:


5

Motivation

Thought Experiment

5

•

describe some techniques for the expression of desired traits in target organisms; and

Instruction

Presentation of Recombinant DNA

•

search online databases for specific traits and source organisms.

Practice

Steps in PCR and Gene Cloning

5

Learning Competency

Enrichment

The learners should be able to discuss the applications of Recombinant DNA Technology (STEM_BIO11/12-III a-b-7)

User of PCR and GMOs

5

Evaluation

Sample Exercise

5

Specific Learning Outcomes:

Materials


35

•

give examples of products from recombinant DNA technology;

Writing materials, recyclable materials for models of plasmids, tape, pens

•

illustrate the use of databases to search genes for desired traits;

Resources

•

describe steps in PCR to amplify and detect a gene of interest;

•

identify the parts of an expression vector;

(1) Genbank, www.ncbi.nlm.nih.gov (2) Protein Data Bank, www.pdb.org

•

explain how genes may be cloned and expressed

36


1. The learning objectives will be presented and the processes in the Central Dogma of Molecular Biology will be reviewed: DNA (gene) ! RNA (transcript)! Protein (trait) 2. Different organisms have different traits based on their genes (DNA sequences). For example, frogs have antimicrobial peptides on their skin. Some jellyfish have proteins that allow them to glow in the dark. Mutations in hemoglobin genes lead to anemia.

Teacher Tip: Be sure to stress that for a gene to add a trait to an organism, the gene for the trait must be inserted within the target organism, and the organism should have the necessary “equipment” (i.e. enzymes, materials ) to produce the protein that results in the trait or desired phenotype.

3. Based on the central dogma, if transcription and translation of genes lead to some traits, then the insertion of certain genes in a given organism may provide it with new traits. This is the basis for the development of genetically modified organisms (GMOs).

MOTIVATION (5 MINS) Thought Experiment

1. The learner may be given a group activity/ thought experiment for constructing a genetically modified organism/trait in a fruit. “Designer Genes group work” I. Arrange the learners into groups of 3 or 4. II. Have them identify a special trait (e.g. large fruit size)

Teacher Tip: Discuss the merits of the different proposed “designer genes” based on the following criteria: 1. 2.

III. Have them identify a source organism (e.g. jackfruit / langka) IV. Have them identify a target organism (e.g. aratilis) V. Have them identify the modified / added trait (e.g. langka-sized aratilis). VI. Have the learners present their work to the rest of the class, and let the class decide on the best proposal.

3.

Originality of the study (i.e. Has anyone done studies of this type before?) Feasibility of the study (How possible is the proposed modification? Can the target organism support the proposed trait? ) Potential Applications of the new organism (What benefits would the recombinant organism provide to society?)

Some examples: Flood-resistant rice Delayedripening fruits

INSTRUCTION (35 MINS) Teacher Tip:

Presentation of Recombinant DNA

1. After the exercise, the learners should now be aware that there are many different traits that can be introduced to organisms to change their properties. The following table shows examples of modified traits using cloned genes and their applications:

MODIFIED TRAIT

Insulin Production

GENE

RECIPIENT

APPLICATION

MODIFICATION

ORGANISM

(FIELD)

Insertion of Human Insulin Gene

Bacteria

Ask the learners on the significance of finding many versus few entries on a given topic in the database.

(Medicine) Production of Human Insulin in Bacteria

FEW entries

MANY

in the database

entries in the database

Topic has not been extensively studied

Topic is much studied

High chance to discover novel traits / applications

information available on is the topic

Low number of research to verify the observations

Difficult to discover new information on the topic

Much

PROS

Pest Resistance

Insertion gene of Bt-toxin

Corn / Maize

(Agriculture) Production of corn plants with increased resistance to corn boxer

Delayed Ripening

Disruption of a gene for a ripening enzyme (e.g. polygalacturonase)

Tomato plant

Agriculture)

CONS

Production of plants with fruits that have delayed ripening fruits. These fruits will survive longer transport time, allowing their delivery to further locations (i.e. export deliveries)

38

Chymosin Production

Insertion of a gene for chymosin

Bacteria

(Industry) Enhance large scale production of chymosin. This enzyme serves as a substitute for rennet in the coagulation of milk. Rennet has to be harvested from calves. The large scale production of this enzyme in bacteria provides an abundant supply of this important component for the cheese production industry.

Web based research:

Search for these different traits and how they may be made useful. This involves the collection of gene sequences in accessible locations, such as databases (e.g. Genbank (www.ncbi.nlm.nih.gov) ; Protein Data Bank (www.pdb.org)). These databases serve like libraries that may be consulted when trying to find specific traits that belong to different organisms. For example, one would want to find out if any work has been done on spider silks. The databases (e.g. Genbank:Nucleotide database) may be searched for entries that contain information on “Spiders, and Silk” (Result: 93615 entries). The results may be screened for more specific studies (e.g. Malaysia, Spiders, and Silk- Result two entries).

PCR Amplification

Once a desired trait is chosen, information must be acquired for either its detection or expression in a given organism.

1.

Detection

Teacher Tip:

Some researchers may be interested in determining if a given gene/trait is available in a particular organism. If no previous research provides this information, researchers may test the DNA of different organisms for the presence of these specific genes. A technique that allows the detection of specific genes in target organisms is called PCR.

Mention that unlike DNA replication in vivo, PCR reactions do not use too many helper enzymes such as helicases and gyrases to help denature and stabilize the template DNA strands. The cyclic heating of the samples is meant to provide the physical separation of the template DNA strands through heat denaturation of the inter-strand H-bonds.

PCR amplification is an in-vitro method that simulates DNA replication in vivo. It utilizes a thermostable (heat-resistant) DNA polymerase that builds single stranded DNA strands unto unwound DNA templates. PCR uses repeated cycles of incubation at different temperatures to promote the unwinding of the DNA template (~95°C); the annealing of a primer (a ~20bp oligonucleotide (recallofRNA primers in DNA replication) onto the strand (~54 - 60°C); andsequence the extension the generated ssDNA strand through thessDNA bindingtemplate of complementary bases to the template strand (~72° C). The thermostability of the polymerase allows it to survive the repeated cycles of denaturation, annealing and extension with little loss of enzyme function. Each cycle of PCR doubles the amount of the target sequence. A typical PCR experiment uses about 35 cycles of amplification. This increases the srcinal amount of the target sequence by 235 (i.e. ~34 billion) times. Gene detection by PCR involves the design of primers that would only bind to sequences that are specific to a target. For example, researchers would want to find out if gene X (e.g. the gene for insulin) is available in a target organism (e.g. a mouse, Mus musculus). Primers may be designed by looking at the available sequences for gene X in the databases (e.g. all the genes for insulin in different organisms; humans, pigs, cows, etc.). The different gene X sequences must be aligned/ compared to match areas of sequence similarity (conserved sequences) and areas of sequence dissimilarity (non-conserved sequences). Primers designed to have the same sequence as the conserved areas will be specific for binding gene X sequences in all the target organisms. Primers designed to have the same sequence as the non-conserved areas will only be specific for the organisms which match its sequence. 40

Primers may be classified as forward or reverse primers. Forward primers are complementary and bind to the reverse complementary (non-coding) sequence of the gene. Reverse primers are complementary and bind to the coding sequence of the gene. STEPS in PCR Amplification Step 0: Undenatured Template ; Temp ~ 54 C; !

Template: double stranded (ds) DNA strand. Complementary sequences are held together by H-bonds 5’ A T GCGATGAGGATATGACCCGATAGATAGAGGTATCTAGAGAT 3’ (Coding strand) 3’ T A CGCTACTCCTATACTGGGCTATCTATCTCCATAGATCTCTA 5’ (Non-coding strand)

Step 1: Template denaturation ; Temp ~ 95 C; !

Template: single stranded (ss) DNA strands; DNA strands are separated; H-bonds between complementary sequences are broken 5’ A T GCGATGAGGATATGACCCGATAGATAGAGGTATCTAGAGAT 3’ (Coding strand) 3’ T A CGCTACTCCTATACTGGGCTATCTATCTCCATAGATCTCTA 5’ (Non-coding strand) Step 2: Primer Annealing ; Temp ~ 54 C (dependent on primer melting temperature); !

Template: ssDNA strands. H-bonds are formed between complementary sequences on the primers and the target sequences. 5’ A T GCGATGAGGATATGACCCGATAGATAGAGGTATCTAGAGAT 3’ (Coding strand) Direction of elongation 5’ GCGATGAGG 3’

CCATAGATC (Reverse Primer)

Direction of elongation (Forward Primer)

3’ T A CGCTACTCCTATACTGGGCTATCTATCTCCATAGATCTCTA 5’ (Non-coding strand)

Teacher Tip: Let the learners recall the antiparallel orientation of the bound primers to the template DNA. If the template is represented from left to right in the 5’ ! 3’ orientation; then the primers should bind near the 3’ end and the primers would be represented 3’ ! 5’ going left to right.

Teacher Tip:

Step 3: New DNA strand elongation ; Temp ~ 72 C; !

The two new dsDNA strands are formed by the elongation of the generated ssDNA and the H-bonds between the complementary sequences on these new strands and their templates. Each of the new dsDNA strands is made up of one old strand from the srcinal template, and one new strand that was generated as a reverse complement of the template. This is called semiconservative replication of the sequence.

Illustrate how by the 2 nd round of PCR the two newly synthesized DNA strands can now be used as templates. For the given example, new strand synthesis will again generate a 37 base pair long product. Repeated cycles of PCR will make this product the predominant type of double stranded DNA in the solution.

New Strand 1:

5’ A T GCGATGAGGATATGACCCGATAGATAGAGGTATCTAGAGAT 3’ (Coding strand) (old) 3’ CGCTACTCCTATACTGGGCTATCTATCTCCATAGATC-5’ (Reverse Primer) (new) New Strand 2:

5’ GCGATGAGGATATGACCCGATAGATAGAGGTATCTAG-3’ (Forward Primer) (new) 3’ T A CGCTACTCCTATACTGGGCTATCTATCTCCATAGATCTCTA 5’ (Non-coding strand) (old) Step 4: Repeat step 1 to 3 for N number of cycles (N is usually 35) PCR Results

The expected product of PCR amplification will depend on the sequences / position at which the primer sequences bind. If the forward primer starts binding at nucleotide 3 (coming from the 5’ end) of a 43bp long gene, and the reverse primer binds at a position complementary to nucleotide 39 of the coding strand, then a 37bp product is expected per cycle of PCR.

New Strand 1:

Nucleotide # 3

Nucleotide # 39 37 bp product

CTAGAGAT 3’ (Coding strand) (old) 5’ A T GCGATGAGGATATGACCCGATAGATAGAGGTAT

3’- CGCTACTCCTATACTGGGCTATCTATCTCCATAGATC – 5’ (Reverse Primer) (new) 42

Note: Other types of organisms (e.g. Yeast, Mammalian Cells, etc.) may also be “transformed” to exhibit new traits. The type of DNA constructs used for insertion of genes into these organisms will vary (e.g. Bacmids, Cosmids, etc.)

New Strand 2:

Nucleotide # 3

Nucleotide # 39 37 bp product

5’ GCGATGAGGATATGACCCGATAGATAGAGGTAT CTAG -3’ (Forward Primer) (new) 3’ T A C GCTACTCCTATACTGGGCTATCTATCTCCATAGATC TCTA 5’ (Non-coding strand) (old)

PCR Applications

Teacher Tip:

PCR may be used to detect the presence of a desired gene in an organism. Depending on the primer design, the expected product may represent only a specific region of the gene or the entire gene itself.

The multiple cloning site (MCS) may contain sequences that may be cut by different restriction enzymes. Stress how the use of two restriction enzymes may control the orientation of the inserted gene in the plasmid. Note: Forward and Reverse primers should not be complementary.

The first case is useful for detection of the gene, or the detection of organisms with that specific gene within a sample. The second case is useful for the amplification of the entire gene for eventual expression in other organisms. The direct amplification/copying of a full gene is part of the process for “cloning” that gene.

2. Cloning and Expression

Some genes provide economically, and industrially important products (e.g. insulin-coding genes; genes for collagen degradation). In some cases, scientists would want to put these genes into organisms for the expression of their products. One example would be the insertion of an insulincoding gene from the human genome into bacteria. This allows the “transformed” bacteria to now produce human insulin as a product. Certain types of bacteria are capable of this process since they are able to take genes within their cell membranes for eventual expression. The genes are normally in the form of small, circular DNA structures called plasmids. The genes found in the inserted plasmid DNA sequence will be expressed as proteins that provide specific traits to the transformed bacteria. The basic components of an expression plasmid are listed in the following table. The purpose of each of these is also provided.

C OM P O N E N T

P U RP OS E

Promoter

Allows the controlled expression of the desired gene in the presence of an inducing agent (e.g. beta- galactosidase; heat treatment (~65 C)

Multiple Cloning Site

DNA sequence or portion for the insertion of the desired gene. This section may contain sequences that will be cut by specific restriction endonucleases ( cuts within the molecule) If both the amplified gene and the plasmid are cut with the same restriction enzyme, then complementary sequences will be generated for each, allowing them to bind together or anneal. The desired gene is inserted into the multiple cloning site through this process.

!

Restriction enzymes cut at specific sequences. EcoR1 Target Sequence:

5’ GAATTC 3’ 3’ CTTAAG 5’

Digestion Reaction Undigested:

Digested dsDNA:

5’ GAATTC 3’

5’ G AATTC3’

3’ CTTAAG 5’

3’ CTTAA G5’

If the desired cut sites are not found in the gene that needs to be inserted; the sequences can be added by including the target sequences in the primers used for PCR amplification. 44

C OM P O N E N T

Multiple Cloning Site

P U R P OS E

PCR Primers: 5’ GCGATGAGG 3’ (Forward Primer) 3’ CCATAGATC 5’ (Reverse Primer) Forward Primer + EcoRI target sequence: 5’ GAATTCGCGATGAGG 3’ Reverse Primer + EcoRI target sequence: 3’ CCATAGATCCTTAAG5’

Inserted Gene Sequence Successful insertion of a gene allows the expression of its protein product. usually provides a specific trait Fluorescent to the “transformed” bacteria. This For example, if the gene for Green Protein is placed within the expression plasmid, bacteria transformed with this plasmid will produce protein (GFP) that will allow the bacterial cells / colonies to glow green in the dark.

Antibiotic Resistance Gene

Provides a way to screen a population of bacteria for those that took up the plasmid. For example, if an ampicillin resistance gene is encoded in the plasmid, then only bacteria which took up the plasmid will be able to grow on media with ampicillin. However, if the ampicillin resistance gene is cut and the gene is inserted here for cloning, then the cell will no longer be resistant to ampicillin. This is a way to select which among the colony of cells actually contain the inserted gene sequence. Bacterial cells whose ampicillin resistance gene have been cut will die in the presence (agar plate) of ampicillin.

PRACTICE (5 MINS)

Teacher Tip:

Steps in PCR and Gene Cloning

1. Let learners give other hypothetically modified or genetically engineered plants and animals which can be used for health, industry, agriculture and for the protection of the environment. 2. Ask learner to draw the parts of an expression vector. 3. Using pieces of paper, allow the learners to illustrate the steps in restriction digestion and PCR

At this point, learners’ imagination could be stretched, but caution the learners that certain ethical principles should be followed and adhered to in the production of genetically modified organisms. Animal welfare should be taken cared of and human cloning must never be conducted.

ENRICHMENT (5 MINS) Uses of PCR and GMOs

1. Discuss how PCR may be used for the detection of disease causing pathogens in a population. For example, it may be used to check if a patient has a dengue virus infection. This is done by using primers that are specific for complementary DNA (cDNA) sequences that correspond to the dengue viruses. If PCR amplification occurs using cDNA from a patient’s blood sample then the patient likely has dengue viruses in his/her blood. 2. Discuss how the cloning and expression of certain genes allows for massive production of the desired product. For example, the cloning and expression of insulin in bacteria allows for the mass production of this necessary protein for use by diabetic patients. Prior to insulin production in bacteria, insulin was harvested from other animals such as pigs. Teacher Tip: Try using other classic restriction enzymes: Ex. Xho1; HindIII

46

EVALUATION (5 MINS) Sample Exercise 1. Give learners a set of known Restriction Enzyme (RE) cut sites: EcoRI

BamH1

5’ GAATTC 3’

5’ GGATTC 3’

3’ CTTAGG 5’

3’ CTTAGG 5’

DNA Sequence (69 bp long)

28

49

5’ ATGCATGGTACGTAGAGTTCCATGAATTCGCCCCTATAGGGTAGCCGAGGATCCTATGCCCGAATGTC 3’ 3’ TACGTACCATGCATCTCAAGGTACTTAAGCGGGGATATCCCATCGGCTCCTAGGATACGGGCTTACAG 5’

Expected Fragment sizes:

With EcoR1 digestion : 28 bp, 41 bp With BamH1 digestion : 20 bp, 49 bp With both EcoR1 and BamH1: 20bp, 28bp, and 21 bp

3. Ask the learners to scan a double stranded DNA sequence to determine the presence of these cut sites. Allow them to provide the fragment sizes expected for using different combinations of the RE on the given sequence. You may choose to give the sequence as linear or circular DNA. Discuss how the fragment sizes will vary if the target sequence is in circular or linear DNA. 4. A similar exercise may be done to locate areas where primer sequences can bind. The expected fragment sizes for PCR amplification using different primers can be tested Example: Forward Primer: 5’ CATGGTACGTAG3’ Reverse Primer: 3’ GCTCTATACGGG 5’

Target Sequence: 4

Product Size: 62 - 4 = 48bp

62

5’ ATGCATGGTACGTAG AGTTCCATGATAGAGCCCCTATAGGGTAGCCGAGCGAGATATGCCCGAATGTC 3’ 3’ TACGTACCATGCATCTCAAGGTACTATCTCGGGGATATCCCATCGGCTC G CTCTATACGGG CTTACAG 5’

48

General Biology 2

60 MINS

Lesson 8.1: History of Life on Earth Content Standard

The learners demonstrate understanding of the major events in the history of life on Earth. Performance Standards


LESSON OUTLINE - DAY ONE


5

Motivation

Discussion: How Old is the Earth?

15

•

create a personal timeline and compare it with the geologic time scale

Instruction

Picture Timeline and Short Film

20

•

design a poster tracing evolutionary changes in a crop plant (e.g., rice or corn) that occurred through domestication

Enrichment

GTS Introductory Worksheet

10

Evaluation

My Life History: A Short Narrative

10

Learning Competency

The learners describe general features of the history of life on Earth, including generally accepted dates and sequence of the geologic time scale and characteristics (STEM_BIO11/12-IIIc-g-8 ) Specific Learning Outcomes


identify the dates and sequence of the periods in the geologic time scale;

•

identify the major events in each major period;

•

describe the characteristics of the major groups of organisms present during a time period;

•

identify types of fossils; and

•

describe causes of mass extinctions.

Materials Visual aids on the geologic time scale; 20 printed pictures of events/ structures/ organisms; computers and internet connection

All Resources listed at the End of this Lesson


Introduction

Communicate Learning Objectives

Introduce the following objectives by asking volunteers to read them aloud: 1. I can identify the dates and sequence of the geologic time scale 2. I can describe the characteristic features of major groups of organisms in each time period.

MOTIVATION (10 MINS) Discussion: How Old is the Earth?

1. What is the age of the Earth? The learners may give various answers from thousands to millions of years. Some will give answers near to 4.6 billion years. Write all the answers on the board and let them think of what the age of the Earth is.) 2. What was the Earth like million of years ago?

When we study the Earth’s age, we are also studying the fossil record and ultimately, the theory of evolution. The Earth is approximately 4.6 billion years old – a very big number ordinary humans can’t easily relate with, especially, the specific time frame when we appeared. Comparing the Earth’s age to one calendar year, events such as the extinction of d inosaurs and the re-discovery of the New World by Columbus would appear relatively much easier. “Understanding the geologic time scale reminds us of our time and place in the universe.”

Big Ideas:(May be written on the board or manila paper and posted on the board. • The Earth is 4.6 billion years old. • Life on Earth arose around 3.5 bill ion years •

Ask learners: “Have you seen the movies Ice Age and The Land Before Time? How was the Earth presented in movies such as these?” Based from what you may have read, describe the Earth million of years ago. The following answers may be given by learners: (1) covered with thick blanket of ice, (2) lots of volcanoes and high mountains, (3) large organisms roamed the land, (4) the atmosphere did not have high oxygen content, (4) asteroids/ meteors frequently hit the surface, (5) the lands moved a lot or the continents were a little closer to each other, (6) volcanic eruptions, (7) a little bit warmer, (8) plants were bigger, (9) humans were not yet around. Accept all answers and ask them what are the possible conditions on the early Earth. The teacher may show a clip from any of the movies depicting ancient earth conditions.) 3. When did man first appear on Earth? Learners may give answers such as millions to thousands years ago. Ask learners to choose the more probable dates and provide evidence for its accuracy. They may enumerate the different hominid species but ask them the approximate time when our species (modern humans) first appeared. Tell them that humans did not co-exist with dinosaurs as what movies 50

ago. Over Earth’s vast history, both gradual and catastrophic processes have produced enormous changes.

Misconceptions: • • •

Humans and dinosaurs existed on the Earth at the same time. Plants and animals on Earth have always existed. The Earth is too big to change.

Teachers must correct the misconceptions learners have about the history of life on Earth.

usually depict. Man could have first appeared about 100 – 150 thousand years ago as shown by artefactual evidences in various sites. The human timeline is rather flexible and debatableevery time we know a specific date, a new discovery is announced and everything gets redated to fit the best estimates.) 4. Distribute the 15 – 20 pictures to some volunteers. Ask each volunteer to post them along the length of the board based on what each thinks occurred first. 5. Let the other learners check what have been posted. They can suggest a possible rearrangement of the pictures. 6. When everybody is satisfied with the lineup, tell them that they are going to watch a short video.

INSTRUCTION (20 MINS) 1. Watch a short clip I. Geologic Time Scale (https://www.youtube.com/watch?v=nofyRleo3Vc ) II. “Four Ways to Understand the Earth’s Age.” (https://www.youtube.com/watch?v=tkxWmhtFGs&spfreload=10 2. Tell everyone to listen andwatch attentively. 3. Use the following questions to guide the learners as they watch the video. I.

What are the four ways mentioned in the film?

II. Why is i t hard to create a timeline of events chronicling Earth’s history? III. What are the divisions of the geologic time scale? 4. Share in class what you have learned from the video. 5. Ask the learners to take a closer look at the timeline constructed on the board. 6. Let them re-arrange (if necessary) based on what they learned from the video.

Teacher Tip: It’s hard for learners to understand geologic events and the time frame where each event took place. It will be easier if everything is connected in a 1- year time frame (calendar year). It is more relevant to see how everything unfolds in a short time span. However, tell them t hat a lot of things can happen in the span of a year. The teacher will print 15 - 20 events (preferably with pictures, if necessary) to be used for this lesson. Refer to the Sample Events List. The pictures should be posted on the front board that will serve as a 1-year timeline. Tell them that they will view the Earth’s history in this time frame. To make it more interesting, attach the 12 months of the year. Ask interesting questions, such as,“Who would like to have a birthday party with dinosaurs?”

Unlocking of division Terms: of the geologic time • EON- largest • • •

scale; spans hundreds to thousands of million of years ago (mya) ERA- division in an Era that span time periods of tens to hundreds of millions of years PERIOD-a division of geologic history that spans no more than one hundred million years EPOCH-the smallest division of the geologic time scale characterized by distinctive organisms

Tip: The teacher may also ask the learners to plot their birthdates side-by-side with the geologic events.

Ask: In which timeframe were you born? What specific events happened the day you were born, using the geologic time scale.

Alternate Video: Geologic Time Scale: Major Eons, Eras, Periods and Epochs- https://www.youtube.com/watch? v=nofyRleo3Vc

ENRICHMENT (10 MINS) 1. Answer the following in your journal. I. The Earth has an incredibly long history. How does understanding of geologic time and the significant geologic events of the past impact your understanding of humans’ unique responsibility and place on earth? II. How does understanding the past help us understand the present? III. Calculate how many generations of humans it would take for us to exist now (assume an average life span of 80 years) (What must we humans do to ensure we are able to exist this long for many generations? 2. Form a dyad and discuss your answers. EVALUATION (5 MINS) 1. Answer the Worksheet on Geologic Time Scale. Submit next meeting. 2. My Life History:Create a timeline of events that happened to you since you were born up to the present time. Choose only 20 events that you think are the most important. Be ready to present your timeline next meeting.

ASSIGNMENT: (5 MINS) 1. Make a table in your notebook of the geologic time scale (GTS) and include the following details; I. Major divisions of the GTS II. Major events and characteristic organisms

52

Teacher Tip: Journaling is a good technique to help some passive learners to jot down their thoughts first then share whatever they have written with a partner. Volunteers may be tapped in advance. The best output will be posted in the room.

Alternate Activity: Time Machine: 1. Look around your community. Make a narrative on how the place looked like several years ago and how it will be several years (maybe after 50 years) from now.

Going Further: If time and space permits, the following activity can be done. Understanding Geologic Time (From: http://www.jsg.utexas.edu/glow/files/ Understanding-Geologic-Time-6-8.pdf)

General Biology 2

60 MINS




LESSON OUTLINE - DAY TWO


5

Motivation

Discussion: How Old is the Earth?

5

•


Instruction

Lecture of the Geologic Time Scale

20

•


Enrichment

The Anthropocene

20

Learning Competency

Evaluation

Quiz

10

The learners describe general features of the history of life on Earth, including generally accepted dates and sequence of the geologic time scale and characteristics (STEM_BIO11/12-IIIc-g-8 )

Materials


All Resources listed at the End of this Lesson



•


•


•


•

describe causes of mass extinctions

Visual aids on the geologic time scale; 20 printed pictures of events/ structures/ organisms; computers and internet connection


Teacher Tip:


This lesson will present formally the lesson on GTS. The learners will understand better the highlights of each time frame in the GTS.

The lesson for today will cover the following topics: 1. Major events in the Geologic Time Scale (GTS) 2. Cambrian Explosion

MOTIVATION (5 MINS) Discussion: How Old is the Earth?

Discussion: How Old is the Earth? Ask the following questions: 1. How old is the Earth? 2. What is the biggest time frame in the GTS? 3. What is the smallest time frame in the GTS?

INSTRUCTION (20 MINS) Teacher Tip:

Lecture of the Geologic Time Scale

The Geologic Time Record is a tabular representation of the major divisions of the Earth’s history. The time intervals are divided and described from the longest to the shortest as EONS, ERAS, PERIODSand EPOCHS.

1. Present a lecture discussion on the Geologic Time Scale 2. The following outline can guide the teacher in the discussion: I. The Geological Time Scale (GTS) A. Four eras- Precambrian; Paleozoic; Mesozoic; Cenozoic B.

Periods under the Paleozoic era - Cambrian, Ordovician, Silurian, Devonian,

Carboniferous, Permian C.

Periods under the Mesozoic era -

Triassic, Jurassic, Cretaceous

D. Periods under the Cenozoic era- Tertiary and Quaternary II. Age in millions of years of each time period III. Major events in the history of life 54

Each period has an approximated time frame and characterized by distinctive features (events and organisms).

The Geologic time is divided into four large segments called Eons: Hadean, Archean, Proterozoic and Phanerozoic. The Phanerozoic is divided into Eras: Paleozoic, Mesozoic, and Cenozoic. Extinction events and appearance of new life forms characterized the divisions among Eras. Smaller divisions, called Periods, characterized by a single type of rock system, make up each Era. Some Periods are further divided into smaller time frame called Epochs. (From: http://goo.gl/ITmoty) There is a mnemonics (memory device) to remember the Periods in exact order (from the earliest to the recent); jumps between periods and epochs. Pregnant

Plentiful

Camels

Early

Often

Oiling

Sit

Might

Down

Prevent

Carefully.

Partial

Perhaps

Rheumatism!

Their Joints Creak?

The teacher can also discuss CAMBRIAN EXPLOSION. CAMBRIAN EXPLOSIONis

the belief that there was a sudden, apparent explosion of diversity in life forms about 545 million years ago. The explosion created the complexity of multi-celled organisms in a relatively short time frame of 5 to 10 million years. This explosion also created most of the major extant animal groups today. SOURCE:http://d32ogoqmya1dw8.cloudfront.net/images/NAGTWorkshops/time/

visualizations_teachtips/variable_time_geologic_time.jpg

The start of the Cambrian was characterized by the breaking up of supercontinent Gondwana into smaller land masses opening up new environmental niches where organisms can colonize and specialize.

** The following PowerPoint presentations might help in organizing your

discussion on this lesson. • • • • •

http://goo.gl/Xfu2dz http://goo.gl/YMUvFL http://goo.gl/yRa5c7 http://goo.gl/45c27A http://goo.gl/CoumSB

Teacher Tip:

ENRICHMENT (20 MINS)

Ask the learners to research if there are evidences to support that the “explosion” is as sudden and spontaneous as it is used to d escribe the fossil record.

The Anthropocene

1. Present to the learners a new proposed Epoch, the Anthropocene. I. What are the evidences that suggest that we are entering/ have entered a new epoch?

This is also a good time to d iscuss how new findings can affect an existing body of knowledge.

2. This can be discussed in a small group of 5 learners.

Let the learners read the following articles about a proposed new epoch, the Anthropocene. • Human impact has pushed Earth into the Anthropocene - http://goo.gl/ fxggQf (04/13/16) • What Is Anthropocene and Are We in It? - http://goo.gl/mq7I9V (04/13/16) • Welcome to the Anthropocene - http://www.anthropocene.info (04/13/16)

EVALUATION (10 MINS) 1. Geologically speaking with reference to the entire history of the earth, the dinosaurs went extinct… A. Shortly after the formation of Earth B. In the first billion years of Earth’s history C. In the most recent 2% of the history of Earth D. Before the first fish formed

3. The Earth is ________ years old. A. 6,000 B. 46,000,000 C. 4,600,000,000 D. There is no way to know

II. How do scientists decide if a new finding should be validated?

4. 100,000 years in the geologic history of Earth would be considered

2. Relative to the percent of time dominating the surface of Earth which organisms have the longest reign? A. Dinosaurs B. Plants C. Prokaryotes D. Eukaryotes E. Humans

A. B. C. D. 56

Immensely long A drop in the bucket Half of Earth's history An extremely significant amount of time

5. Understanding geologic time is significant because it helps us A. Understand humans’ impact on our environment

6. Which organism first dominated Earth? A. Dinosaurs

B. Understand the evolution of organisms over time C. Understand the possibility for life on other planets

B. Insects C. Plants

D. Understand the process of evolution E. All of the above

D. Fish E. Bacteria

ASSIGNMENT

Answer Key:

1. What are fossils? How are they formed?

Answer with discussion must b e given by the teacher. 1. C 2. C 3. C 4. B

2. List down the types of fossils and given examples. 3. How do we measure the age of fossils? 4. What are mass extinctions? How many mass extinctions events happened in the GTS?

5. 6.

B E

Teacher Tip: See to it that everyone has a clear understanding of the geologic time scale. There is no need to remember all the events in each period.

General Biology 2

60 MINS




create a personal timeline and compare it with the geologic time scale; and

•


Learning Competency


LESSON OUTLINE - DAY THREE


5

Motivation

Questions on Dinosaurs

5

Instruction

Types of Fossils

50


Resources (1) Freeman, S. Biological Science. 3rd ed. 2008. California: Pearson Benjamin Cummings. pp. 503-525. (2) Reece, JB, LA Urry, ML Cain, S Wasserman, PV Minorsky, RB Jackson. Campbell Biology. 9th ed. 2014. Illinois: Pearson Education Inc. pp. 480-499.




•


•


•


•


58

(3) Russell PJ, SL Wolfe, PE Hertz, C Starr, B Mc Millan. Biology: the Dynamic Science. 2008. California: Brooks/Cole CENGAGE Learning. pp. 419-439.

Additional Resources listed at the End of this Lesson

INTRODUCTION (5 MINS) The lesson for today will cover the following topic: 1. The types of fossils 2. Ways fossils are formed and how fossils’ ages are determined 3. Mass extinctions- causes and frequency in the GTS MOTIVATION (5 MINS) 1. Where did scientists discover the first dinosaurs? 2. Who coined the term dinosaurs? 3. How did the discovery of dinosaurs make scientists become more interested in the geologic record? 4. How can fossils be used as evidence for the evolution of living forms? INSTRUCTION (50 MINS) 1. The teacher will post on the board examples of fossils and let the learners identify the type. FOSSILS are evidences of organisms that lived in the past. They can be actual remains like bones, teeth, shells, leaves, seeds, spores or traces of past activities such as animal burrows, nests and dinosaur footprints or even the ripples created on a prehistoric shore. In exceptional preservation, fine details such as srcinal color and individual muscle fibers are retained, features often visible in electron microscopes. This is referred to as the “Medusa effect.” (From: http://www.bbc.co.uk/nature/fossils/Lagerstätte)

Teacher Tip: An alternative could be to show a clip f rom the movie Jurassic Park or Jurassic World.

The following sites provide information about Fossils: • http://teacher.scholastic.com/scholasticnews/ magazines/scienceworld/assets/SWPOWERPOINT-FOSSILS.ppt - (Downloaded 04/15/16) • http://www.enchantedlearning.com/subjects/ dinosaurs/dinofossils/Fossiltypes.html (Downloaded 04/15/16) • http://www.livescience.com/37781-how-dofossils-form-rocks.html - (Downloaded 04/15/16) • http://www.bbc.co.uk/nature/fossils (Downloaded 04/15/16) •

http://www.whatisafossil.net - (Downloaded 04/15/16)

T YP E S OF F O SSI L S

DE SC R I P T I O N

E X A M P LE S

Molds

Impression made in a substrate = negative image of an organism

Casts

Whenamoldisfilledin

Petrified

Organicmaterialisconvertedintostone

Shells Bonesandteeth Petrifiedtrees; Coal balls (fossilized plants and their tissues, in round ball shape)

Original Remains

Preserved wholly (frozen in ice, trapped in tar pits, dried/ dessicated inside caves in arid regions or encased in amber/ fossilized resin)

Carbon Film

Carbon impression in sedimentary rocks

Trace / Ichnofossils

Record the movements and behaviors of the organism

Woolly mammoth; Amber from the Baltic Sea region Leaf impression on the rock Trackways, toothmarks, gizzard rocks, coprolites (fossilized dungs), burrows and nests

THE SIX WAYS OF FOSSILIZATION

Teacher Tips:

1. Unaltered preservation - Small organism or part trapped in amber, hardened plant sap 2. Permineralization/ Petrification - The organic contents of bone and wood are replaced with silica, calcite or pyrite, forming a rock-like fossil

The teacher may also mention that more than 90 percent of all organisms that have ever lived on Earth are extinct (http://goo.gl/K83SA). This is due to mass extinctions events that wiped out organisms in the past. The following sites offer explanations on these mass extinction events.

3. Replacement - hard parts are dissolved and replaced by other minerals, like calcite, silica, pyrite, or iron 4. Carbonization or Coalification - The other elements are removed and only the carbon remained

•

5. Recrystalization - Hard parts are converted to more stable minerals or small crystals turn into larger crystals

•

6. Authigenic preservation - Molds and casts are formed after most of the organism have been destroyed or dissolved

60

•

Big 5 Mass Extinction Events - http:// www.bbc.co.uk/nature/extinction_events (Downloaded 04/16/16) The Great Dying - http://science.nasa.gov/ science-news/science-at-nasa/ 2002/28jan_extinction/ - (Downloaded 04/16/16) Mass Extinctions - http:// science.nationalgeographic.com/science/ prehistoric-world/mass-extinction (Downloaded 04/16/16)

DATING FOSSILS

Knowing the age of a fossil can help a scientist establish its position in the geologic time scale and find its relationship with the other fossils. There are two ways to measure the age of a fossil: relative dating and absolute dating. 1. RELATIVE DATING

I. Based upon the study of layer of rocks II. Does not tell the exact age: only compare fossils as older or younger, depends on their position in rock layer III. Fossils in the uppermost rock layer/ strata are younger while those in the lowermost deposition are oldest How Relative Age is Determined

I. Law of Superposition: if a layer of rock is undisturbed, the fossils found on upper layers are younger than those found in lower layers of rocks II. However, because the Earth is active, rocks move and may disturb the layer making this process not highly accurate Rules of Relative Dating

(From: http://staff.harrisonburg.k12.va.us/~esutliff/forms/Relative_Dating_1334236393.ppt) : Sedimentary layers are deposited in a specific time- youngest A. LAW OF SUPERPOSITION rocks on top, oldest rocks at the bottom : Deposition of rocks happen horizontally- tilting, B. LAW OF ORIGINAL HORIZONTALITY folding or breaking happened recently

C. LAW OF CROSS-CUTTING RELATIONSHIPS: If an igneous intrusion or a fault cuts through existing rocks, the intrusion/fault is YOUNGER than the rock it cuts through Try this exercise on radioactive dating: Carbon-14 Dating:http://www.starhop.com/library/pdf/studyguide/high/

brsp-15carbondating.pdf INDEX FOSSILSguide ( fossils/ indicator fossils/ zone fossils): fossils from short-lived

organisms that lived in many places; used to define and identify geologic periods 2. ABSOLUTE DATING

•

Determines the actual age of the fossil

•

Through radiometric dating, using radioactive isotopes carbon-14 and potassium-40

•

Considers the half-life or the time it takes for half of the atoms of the radioactive element to decay The decay products of radioactive isotopes are stable atoms.

•

Take a look at the table below. A living organism has carbon-14. For the amount of Carbon in the organism’s body to become half, it will take about 5,700 years; which is the half-life of carbon-14. Fill up the remaining data in the table. What is the limit in using carbon-14 as a measure to determine a fossil’s age?

62

General Biology 2

60 MINS


The learners demonstrate understanding of the major events in the history of life on Earth. Performance Standard



•


LESSON OUTLINE - DAY FOUR

Practice

Creation of Fossils

50

Wrap Up

Clean Up

10


Resources

Learning Competency

(1) Freeman, S. Biological Science. 3rd ed. 2008. California: Pearson


Benjamin Cummings. pp. 503-525. (2) Reece, JB, LA Urry, ML Cain, S Wasserman, PV Minorsky, RB Jackson. Campbell Biology. 9th ed. 2014. Illinois: Pearson Education Inc. pp. 480-499.


(3) Russell PJ, SL Wolfe, PE Hertz, C Starr, B Mc Millan. Biology: the Dynamic Science. 2008. California: Brooks/Cole CENGAGE Learning. pp. 419-439.


identify the dates and sequence of the periods in the geologic time scale

•

identify the major events in each major period

•

describe the characteristics of the major groups of organisms present during a time period

•

identify types of fossils and

•

describe causes of mass extinctions


Teacher Tip: PRACTICE (50 MINS) Making fossil is a fun way to get involved in 1. The learners are going to make fossils from a natural and man-made object. science. There are a lot of online sites to guide you 2. There are two methods used to create fossils. on how to create cheap replicas of fossils. A. Imprint The activity can be a little messy, so instruct the I. Choose the object you want to make a fossil of. Any natural object (shells, leaves, learners to use newspapers or this can be done in animal bone) will do as long as it fits in the container. If you choose leaves, be sure it is an open area. not dry. The following materials are needed for this activity. II. Coat the object with petroleum jelly. This will keep the object from sticking to the 1. A small natural object (shell, bone, leaf) plaster when you try to remove it. Coat it thoroughly. 2. Any small toy 3. Clay III. Mix plaster and water in a bowl. Follow the directions on the plaster of Paris 4. Petroleum jelly packaging. Mix them together thoroughly and let the concoction sit for a few minutes 5. Plaster of Paris without stirring. You should need about 2x more water than plaster, but you can adjust 6. Disposable dish the ratio as you see fit. IV. Press the object into the plaster of Paris. Be careful not to push too hard! Now your Teacher Tip:

part is done; all it has to do is dry. Set it aside and check it the next day; drying will take at least one day. V. Remove the object. After you've waited 24 hours, pop your natural item out of the plaster of Paris. It's just like a shell that was enveloped in soil for thousands of years. It was disintegrated and this image was left behind. B. 3-D Object (Cast)

I. Choose the object you want to make a fossil of. Any natural object (shells, leaves, animal bone) will do as long as it fits in the container. If you choose leaves, be sure it is not dry.

Given that this can be messy, tell learners to work on top of old newspapers. Tell them not to throw plastic of Paris in the sink or drainage in order for them not to get clogged with the dried up materials. Provide a container for them to put all waste materials. It will take 1 - 2 days to completely dry and harden the fossil model. Give incentives/ small tokens to those who made the best fossils.

II. Combine the plaster of Paris with water. Use 1 part plaster of Paris to 2 parts water and mix well in a paper cup with a plastic spoon. Let it sit while you work with the clay. III. Choose an object as the template of your fossil. Generally, leaves, shells, branches, or bones work best. Just make sure you have enough clay and plaster to cover it. IV. Knead the modeling clay until it is soft and pliable. This will be what your object rests and forms an impression in. It needs to be kneaded until it can cover the area of your object. V. Coat the object with petroleum jelly. Firmly yet slowly press it into the modeling clay to 64

make an impression. The petroleum jelly prevents it from sticking to the clay, so be generous. Remove the object carefully to create a mold in the shape of the item you used. VI. Fill the impression left by your object with plaster of Paris. Smooth the plaster to the level of the clay to form a flat surface. Place your clay and plaster mold on a newspaper, paper towel, or other disposable surface and allow it to harden. You'll need to wait at least overnight, but 2 or 3 days is preferable and safer. VII. Peel the clay off the hardened plaster to free the fossil. The shape of your object should be recreated in the plaster, details intact.

WRAP UP (10 MINS) 1. Tell the learners to clean up and put all the output in one corner of the room for them to dry up. 2. Tell them to label their works with masking tape.

General Biology 2

60 MINS


The learners demonstrate understanding of the major events in the history of life on Earth.

LESSON OUTLINE - DAY FIVE

Performance Standards

Evaluation


Materials

Summative Assessment

•

create a personal timeline and compare it with the geologic time scale; and Visual aids on the geologic time scale; 20 printed pictures of events/

•


Learning Competency

The learners describe general features of the history of life on Earth, including generally accepted dates and sequence of the geologic time scale and characteristics (STEM_BIO11/12-IIIc-g-8 ) Specific Learning Outcomes



•


•


•


•


66

60

structures/ organisms; computers and internet connection

Resources (1) Freeman, S. Biological Science. 3rd ed. 2008. California: Pearson Benjamin Cummings. pp. 503-525. (2) Reece, JB, LA Urry, ML Cain, S Wasserman, PV Minorsky, RB Jackson. Campbell Biology. 9th ed. 2014. Illinois: Pearson Education Inc. pp. 480-499. (3) Russell PJ, SL Wolfe, PE Hertz, C Starr, B Mc Millan. Biology: the Dynamic Science. 2008. California: Brooks/Cole CENGAGE Learning. pp. 419-439.


SUMMATIVE ASSESSMENT

1. Geologic Time Scale Practice Go to this site and try the quiz. (There is no need to memorize the smaller divisions of the geologic time scale.) http:// www.geosci.ipfw.edu/gildner/TimeScalePractice.html (Downloaded 04/16/16) 2. Geologic Time Scale Events Go to this site and try the quiz. http://www.glencoe.com/qe/ scienceOLC.php?qi=6024 (Downloaded 04/16/16) 3. Practice Quiz for the Nature of Fossils Go to this site and try the quiz. http://anthro.palomar.edu/time/ quizzes/timquiz1.htm (Downloaded 04/16/16) MULTIPLE CHOICE . Choose

the letter of the correct answer.

1. The largest division of the geologic time scale is the A. Eon B. Era C. Period D. Epoch 2. The Mesozoic Era was the Age of Reptiles while the current Cenozoic Era is the Age of A. Mammals B. Birds C. Humans D. Technology

3. The layers in sedimentary rocks are also called A. eras B. epochs C. strata D. gaps 4. The movie “Jurassic Park” got its title from which era? A. Paleozoic B. Mesozoic C. Cenozoic D. Holozoic 5. During which era were the first land plants formed? A. Cambrian B. Pre-Cambrian C. Paleozoic D. Mesozoic 6. The era of middle life, a time of many changes on Earth A. Paleozoic B. Mesozoic C. Cenozoic D. Holozoic 7. What is the longest part of Earth’s history where trace fossils appeared. A. Pre-Cambrian B. Paloezoic C. Mesozoic D. Cenozoic

8. The geologic time scale is subdivided into 4 groups. List them from the largest to the smallest.

TRUE OR FALSE. Write

True if the statement is correct and False if

it is not.

A. Eons, periods, epochs, eras B. Eras, eons, periods, epochs

1. Fossils give clues about the past. 2. Animals that are extinct are still alive today.

C. Epochs, periods, eras, eons D. Eons, eras, periods, epochs

3. Scientists do not know for sure what happened to the dinosaurs. 4. A mold is a cast filled in with sediments. 5. Soft body parts cannot be fossilized. 6. Paleontology is the study of fossils.

9. The end of this era was believed to be caused by a comet or asteroid colliding with Earth, causing a huge cloud of dust and smoke to rise into the atmosphere, blocking out the sun.

7. A wooly mammoth’s footprint is a trace fossil. 8. Distinctive fossils used to determine the ages of rocks are called scale fossils.

A. Paleozoic B. Holozoic

9. Saber - toothed tiger is more likely preserved in amber.

C. Mesozoic D. Cenozoic

10. Fossils are most likely found in sedimentary rocks.

10. Which geologic event occurred during the Mesozoic era? A. Pangaea formed B. Asteroids killed the dinosaurs C. The Rocky Mountains formed D. The Pleistocene Ice Age began

68

RESOURCES:

NOTES:

1. 2. 3. 4.

The Geologic Time Scale: http://www.uky.edu/KGS/education/geologictimescale.pdf (Retrieved 07/08/15) What Is a Fossil: http://www.discoveringfossils.co.uk/whatisafossil.htm (Retrieved 04/16/16) BBC- Fossils: http://www.bbc.co.uk/nature/fossils (Retrieved 04/16/16) How Fossils Form: http://www.enchantedlearning.com/subjects/dinosaurs/dinofossils/Fossilhow.html (Retrieved 04/16/16)

VIDEOS:

1. 2. 3. 4. 5. 6.

Evolution (1971 animation)- https://www.youtube.com/watch?v=T1_vnsdgxII (viewed 07/08/15) Geologic Time Scale The Geologic Time Scale: https://www.youtube.com/watch?v=r10oh1NHKv4&spfreload=10 (viewed 07/08/15) The Geologic Time Scale: https://www.youtube.com/watch?v=nofyRleo3Vc (viewed 07/24/15) Four Ways to Understand the Earth’s Age: https://www.youtube.com/watch?v=tkxWmh-tFGs&spfreload=10 (viewed 07/08/15) The History of Earth: https://www.youtube.com/watch?v=RQm6N60bneo (viewed 07/08/15)

FURTHER:

1. 2. 3. 4. 5. 6. 7. 8. 9.

Advance learners can explore these sites beyond class. Deep Time: A History of the Earth – Interactive Infographic: http://deeptime.info (viewed 07/09/15) National Museum of Natural History – Geologic Time: http://www.nmnh.si.edu/paleo/geotime/index.htm (viewed 07/09/15) Abiogenesis: https://www.youtube.com/watch?v=W3ceg--uQKM (viewed 07/08/15) http://mitep.mtu.edu/include/documents/2013/presentations/What_is_the_Geologic_Time_Scale_DWagner.pdf http://ed.ted.com/lessons/the-earth-s-age-in-measurements-you-can-understand-joshua-m-sneideman#review http://www.stratigraphy.org/index.php/ics-chart-timescale http://deeptime.info http://www.nmnh.si.edu/paleo/geotime/index.htm http://www.enchantedlearning.com/subjects/dinosaurs/dinofossils/Fossiltypes.html

Other possible sources of quiz items on fossils: (Downloaded 04/16/16) 1. https://mrssmiths4thportfolio.wikispaces.com/file/view/fossil+quiz.pdf 2. http://www.marcom.com.au/SGuides/ZZVECS/6VCSQS06.pdf 3. https://www.nps.gov/blca/learn/education/upload/fossils-2.pdf 4. http://www.biorules.org/Biology/articles/hist_life/Chap12PracTest.pdf 5. http://scioly.org/wiki/images/4/44/2015CT_FOSS1_TESTKEY.pdf

General Biology 2

100 MINS

Lesson 9.1: Mechanisms that Produce Change in Populations (1 of 2) LESSON OUTLINE

Content Standard

The learner will be able to understand the Hardy- Weinberg Principle and use its equation to test whether a gene (or a population in a larger scale) is in equilibrium or it is changing.

Introduction Definition of Terms Motivation

Observation

Learning Competency

Instruction

Lecture on Hardy-Weinberg Principle

The learners shall be able to explain the mechanisms that produce change in populations from generation to generation ( STEM_BIO11/12-IIIc-g-9 )

60

Practice

Word Problem

10


Enrichment

Group Work

15

Evaluation

Assignment

20

Attachment

Teaching Hardy-Weinberg in the Classroom


explain that genetic variation is the prerequisite and should therefore be present for any genetic process to cause change in populations from generation to generation;

•

state the Hardy-Weinberg Principle;

•

enumerate the conditions that should be present for a gene or in a larger scale, a population, to attain Hardy-Weinberg equilibrium; and

•

calculate gene and genotype frequencies and derive the Hardy-Weinberg equation

10 5

Materials Pictures; chocolate and milk coated fish-shaped pretzels available in most supermarkets; paper, pen, and calculator


70

Additional Resources at the End of this Lesson

INTRODUCTION (5 MINS) Definition of Terms

1. Describe examples of genetic variation observed in a population. 2. Discuss the sources of variation. 3. Define the following terms: gene pool, gene orallele frequency, and genotype frequency.

Teacher Tip: Remind your learners about the process of meiosis discussed in the previous semester. Let them recall how genetic variation is generated through meiosis. • independent assortment mixes paternal and maternal chromosomes in the gametes • crossing over leads to new combination of alleles You may also mention that fertilization mixes alleles from two parents. Discuss mutation as the ultimate source of variation since it is the only genetic process that can create new alleles.

MOTIVATION (5 MINS) Observation

1. Show your learners different photographs showing variation or differences among individuals. Examples: family picture showing differences in appearance of parents and siblings; group pictures of friends or colleagues or even a class picture; picture of different dog breeds; picture of different varieties of pepper or any fruit or vegetable; etc.

Teacher Tip: From the pictures, let the learners recognize the similarities and more importantly the differences between individuals belonging to the same species.

2. You may also ask them to look at each other and tell them that all of us belong to the same species yet we look differently.

INSTRUCTION (60 MINS) Lecture on Hardy-Weinberg Principle

1. Give a lecture on the following: I. Statement of the Hardy-Weinberg Principle II. Conditions that should be satisfied for a gene in a population to be in Hardy-Weinberg equilibrium III. Mathematical equation of the Hardy-Weinberg Principle

Teacher Tip: You have to emphasize to the class that when gene frequencies remain constant from generation to generation, the population exhibits HardyWeinberg equilibrium and is therefore a nonevolving population. When any of the conditions is not fulfilled, there would be changes in gene frequencies and the population is said to be evolving.

2. Demonstrate to the class the Hardy-Weinberg Principle. The demonstration can be adapted from: Berkeley, C. Teaching Hardy-Weinberg in the classroom (http://www.carolina.com/ teacher-resources/Interactive/teaching-hardy-weinberg-in-the-classroom/tr10630.tr). Demonstrate only the given Activity 1 (Hardy Weinberg Equilibrium). The other activity will be done in the second part of the lesson. 3. Show how to calculate the gene and genotype frequencies and how the Hardy-Weinberg mathematical equation is derived. Consider flower color in a hypothetical population of 1000 plants with two alleles, R 1 and R2. These alleles show incomplete dominance, thus plants homozygous for allele R1 will have red flowers (R1R1), plants homozygous for allele R2 will have white flowers (R2R2) and heterozygote plants (R1R2) will have pink flowers. Supposed this population include 490 plants with red flowers, 420 with pink flowers and 90 with white flowers. Calculate the gene and genotype frequencies in the given generation and in the next generation. Here is the solution to this given problem. Since the plants are diploid, there will be a total of 2,000 copies of the alleles for the locus (1,000 x 2 = 2,000). R 1 accounts for 980 of these copies (490 x 2 = 980) for R 1R1 plants plus 420 x 1 = 420 for R 1R2 plants. Thus, the frequency of the R1 allele is 1,400/2,000 = 0.7 (70%). Let us use p to designate the frequency of this allele (R1) and q for the frequency of the other allele (R2). Therefore, the frequency of R1 in the gene pool of this population is p = 0.8 and since there are only two alleles for this gene, the frequency of R2, represented by q is q = 1-p = 0.3 (30%). The sum of allele frequencies must always be equal to 1. Let us now see how we can use the gene and genotype frequencies to illustrate a population in Hardy-Weinberg equilibrium for this given locus. Let us assume that the members of the population have equal chances of mating with each other meaning there is random union of sperms and eggs. Using a diagram similar to a Punnett square and using the rule of multiplication, the genotypes of the progenies of the next generation can be obtained.

72

Teacher Tip: For the class demonstration, instead of the given American brand of crackers, use locally available brands like the chocolate and milk coated fishshaped biscuits available in most supermarkets (e.g. Knick Knacks). Alternatively, this can be done as a group activity especially if you have the right amount of resources. It is much easier to teach the Hardy-Weinberg equation if the learners calculate gene and genotype frequencies with you. Therefore, you should pause frequently to give the learners enough time to actively process the information and practice the calculations.

The probability that two R1 alleles will come together is p x p = p2 = 0.7 x 0.7 = 0.49; therefore the frequency of R1R1 individuals in the next generation is 49%. The frequency of R1R2 plants is expected to be q x q = q2 = 0.3 x 0.3 = 0.09, or 9%. The heterozygotes (R1R2) can arise in two different ways: 1) the egg provides the R1 allele and the sperm provides the R2 allele, thus the resulting heterozygote will be p x q = 0.7 x 0.3 = 0.21; 2) the egg provides the R2 allele and the sperm provides the R1 allele, thus the resulting heterozygote will be q x p = 0.3 x 0.7 = 0.21. The frequency of the heterozygote is the sum of these two possibilities: pq + qp = 2pq = 0.21 + 0.21 = 0.42, or 42%. The genotype frequencies must add up to 1 (100%). The equation for Hardy-Weinberg equilibrium for a locus with two alleles can be stated as:

If you compute for the gene frequencies in the next generation: p (frequency of R1) is the square root of p2, that is the square root of 0.49 = 0.7; and the frequency of R2 is q = 1- p, that is 1- 0.7 = 0.3. Take note that the gene and genotype frequencies of the srcinal population and the next generation are the same or are constant, implying that the population with regards to flower color is in Hardy-Weinberg equilibrium.

Teacher Tip:

PRACTICE (15 MINS) Word Problem

1. Aside from the example you used, give another problem for the learners to work on.

Problems/questions can be obtained from the listed references. If you do not have copies of the books in the list, you may refer to any General Biology books or Genetics books.

ENRICHMENT (15 MINS) Group Work

2. Divide your learners into groups, with each group having five to six members. Let the learners in each group discuss among themselves how they answered the given problems. After ten minutes of group discussion, explain to the class the correct answers.

Teacher Tip: You have to go around the groups to check if they are doing things correctly.


1. Give two questions/problems (one on dominant trait and another on co-dominant trait) as assignment to be submitted the next meeting. Instruct your learners to show the solution to the problems. 2. The assignment will be given 10 points for perfect score. The solution will be 70% of the score and the final answer is 30%.

Resources PAPERS ONLINE:

TEACHING HARDY-WEINBERG IN THE CLASSROOM Adapted from: Candace Berkeley, http://www.carolina.com/teacher-resources/Interactive/teaching-hardyweinberg-in-the-classroom/tr10630.tr Materials

•

2 Large Bags of Milk-coated Fish-shaped Biscuits (e.g. Knick Knacks)

•

2 Large Bags of Chocolate-coated Fish-shaped Biscuits (e.g. Knick Knacks)

•

Plates or Napkins

•

Learner Data Sheet (optional) 74

(1) Brewer, MS and E Grant. Teaching evolution through the Hardy-Weinberg Principle: A realtime, active-learning exercise using classroom response devices. 2013. The American Biology Teacher, 75(7):476-479; DOI: 10.1525/abt.2013.75.7.6. (2) Berkeley, C. Teaching Hardy-Weinberg in the classroom. http://www.carolina.com/teacherresources/Interactive/teaching-hardyweinberg-in-the-classroom/tr10630.tr (3) The teacher friendly guide to evolution: Hardy-Weinberg Equilibrium. http:// bivalves.teacherfriendlyguide.org/index.php? option=com_content&view=article&id=30:har dy-weinbergequilibrium&catid=27&Itemid=126

Preparation and Procedure

1. Pour the contents of all 4 bags of Fish-shaped Biscuits into a large bowl which will represent the lake. 2. Depending on class size and your resources, you may wish to divide your class into pairs or groups. 3. Give each pair or group a copy of the Learner Data Sheet, if desired, and a plate or napkin; have them wash their hands before beginning. 4. Explain that dark brown (chocolate-coated) biscuits are homozygous recessive individuals (gg) and that white (milk-coated) biscuits display the dominant phenotype and therefore may be either homozygous dominant (GG) or heterozygous (Gg). Activity 1: Hardy-Weinberg Equilibrium

1. Have each learner pair or group remove 10 fish-shaped biscuits from the lake and place them on the plate or napkin. In order to ensure random choice, have learners close their eyes. 2. Learners record the number of white and brown biscuits in Table 1 as Generation 1. 3. Instruct learners to close their eyes and to select and eat 3 of their 10 biscuits at random. (It is important that this step be random; learners must not introduce bias.) 4. Have learners return to the lake, close their eyes, and randomly select 3 new biscuits to replace those that were eaten. 5. Learners then record their new count of white and brown biscuits in Table 1 as Generation 2. 6. Have learners repeat steps 3–5 until they have data for 5 generations. 7. After data have been collected, have learners use the Hardy-Weinberg equation to calculate p, q, p2, q2, and 2pq for each generation. 8. Collect class data. Activity 2: Hardy Weinberg and Natural Selection

1. Have each learner pair or group remove 10 fish-shaped biscuits from the lake and place them on the plate or napkin. In order to ensure random choice, have learners close their eyes. 2. Learners record the number of white and brown biscuits in Table 2 as Generation 1.

3. Instruct learners to select and eat 3 of their brown biscuits. (If they do not have 3 brown ones on their plate, have them substitute a white one. The point, though, is to select against the brown phenotype over a few generations.) 4. Have learners return to the lake, close their eyes, and randomly select 3 new biscuits to replace those that were eaten. It is important that this step be random; learners must not introduce bias. 5. Learners then record their new count of white and brown biscuits in Table 2 as Generation 2, and then, as before, select 3 brown ones to eat. 6. Have learners repeat steps 3–5 until they have data for 5 generations. 7. After data have been collected, have learners use the Hardy-Weinberg equation to calculate p, q, p2, q2, and 2pq. 8. Collect class data. After the Performance of Activities 1 and 2

Once class data are collected, have learners compare the genotype frequencies in both simulations. The class data from the first activity should result in fairly constant frequencies over the 5 generations. When selection is introduced in the second activity, the genotype frequencies should vary over the 5 generations. Discuss what conditions must exist for frequencies to remain stable over multiple generations. What do changing frequencies indicate in a population?

76

General Biology 2

120 MINS

Lesson 9.2: Mechanisms that Produce Change in Populations (2 of 2) Content Standard

The learner will be able to understand how different genetic mechanisms change the gene and genotype frequencies and ultimately cause change in populations.

Introduction Quick Review

5


Motivation

Inquiry

5

Instruction

Lecture on Genetic Mechanisms

60

Learning Competency

Practice

Word Problem

15

The learners shall be able to explain the mechanisms that produce change in populations from generation to generation (STEM_BIO11/12-IIIc-g-9)

Enrichment

Group Work

15


Evaluation

Assignment

20

LESSON OUTLINE


calculate problems that involve changes in gene and genotype frequencies


Materials

•

enumerate the genetic mechanisms that cause change in populations;

•

explain how each genetic mechanism causes change in populations; and

Chocolate and milk coated fish-shaped biscuits available in most supermarkets; paper, pen, and calculator

•

calculate the change in gene and genotype frequencies cause by selection


Additional Resources at the Back


Teacher Tip:

Quick Review

Let your learners recall the Hardy-Weinberg principle and the conditions that should be satisfied for equilibrium to be attained.

1. Give a quick review of Hardy-Weinberg principle and the conditions that should be satisfied to attain equilibrium.

MOTIVATION (5 MINS)

Teacher Tip:

Inquiry

1. You may ask your learners: ‘What would happen if any one of the conditions is not satisfied?’ Ask them to recite their answers.

You have to make your learners realize that if any one of the conditions is not met or satisfied, equilibrium (constant gene and genotype frequencies) will not be attained. Therefore, the gene and genotype frequencies will change and eventually this will cause changes in the population and will ultimately lead to species change and evolution.

INSTRUCTION (60 MINS) Lecture on Genetic Mechanisms

1. Give a lecture on the genetic mechanisms that change gene and genotype frequencies of populations: I. mutation II. selection III. gene flow or migration IV. genetic drift 2. Demonstrate to the class how gene and genotype frequencies change when selection is present. The demonstration can be adapted from: Berkeley,C. Teaching Hardy-Weinberg in the classroom (http://www.carolina.com/teacher-resources/Interactive/teaching-hardyweinberg-in-the-classroom/tr10630.tr). Use the given Activity 2 (Hardy Weinberg and Natural Selection). 3. Based on the calculations done during the activity, discuss how selection changes the gene and genotype frequencies in a population. Let us assume that these are the calculated values from an activity described above done by a class where there was selection against the white fish phenotype: 78

Teacher Tip:

For the class demonstration, instead of the given American brand of crackers, use locally available brands like the chocolate and milk coated fishshaped biscuits (e.g. Knick Knacks) available in most supermarkets. Alternatively, this can be done as a group activity especially if you have the right amount of resources. It is much easier to teach the use of HardyWeinberg equation in the presence of selection if the learners calculate gene and genotype frequencies with you. Therefore, you should pause frequently to give the learners enough time to actively process the information and practice the calculations.

Generation

No. of black No. of white fishes fishes

p

q

p2

q2

2pq

1

100

80

0.34

0.66

0.12

0.44

0.44

2

128

72

0.37

0.63

0.14

0.46

0.40

3

126

54

0.45

0.55

0.20

0.50

0.30

4

138

42

0.52

0.48

0.27

0.50

0.23

5

150

30

0.59

0.41

0.35

0.48

0.17

4. Illustrate to your learners the change in gene and genotype frequencies by showing graphs that reflect the changes. Make two graphs, one for genotype frequencies and another for gene frequencies. Plot the values of the gene/genotype frequencies in the x axis and the generations in the Y axis. Discuss to your learners what they can observe about the graphs. They should clearly see the occurrence of change across five generations. 5. You may also compute the change in gene frequency from one generation to another generation. Example: change in p and q from generation 1 to 2: !p = p2 – p1 = 0.37 – 0.34 = 0.0 3; !q = q2 – q1 = 0.63 – 0.66 = -0.03

This means that there is increase in the frequency of p by 0.03 and a corresponding decrease in q after one generation of selection against the white phenotype. 6. Take note that since there is selection against the white phenotype, there was continuous decrease in the genotype and gene frequencies and a corresponding increase in the gene and genotype frequencies for the black phenotype.

PRACTICE (15 MINS) Word Problem

1. Aside from the examples that you used to illustrate the effect of selection, give another word problem on selection for the learners to work on.

Teacher Tip: Problems/questions can be obtained from the listed references. If you do not have copies of the books in the list, you may refer to any General Biology books or Genetics books.

ENRICHMENT (15 MINS) Group Work

Teacher Tip:

1. Divide your learners into groups, with each group having five to six members. Let the learners in each group discuss among themselves how they answered the given problem. After ten minutes of group discussion, explain to the class the correct answer.

You have to go around the groups to check if they are doing things correctly.


1. Give a questions/problem on selection as assignment to be submitted the next meeting. Instruct your learners to show the solution to the problem. 2. The assignment will be given 10 points for perfect score. The solution will be 70% of the score and the final answer is 30%.

Resources PAPERS ONLINE:

(1) Brewer, MS and E Grant. Teaching evolution through the Hardy-Weinberg Principle: A realtime, active-learning exercise using classroom response devices. 2013. The American Biology Teacher, 75(7):476-479; DOI: 10.1525/abt.2013.75.7.6. (2) Berkeley, C. Teaching Hardy-Weinberg in the classroom. http://www.carolina.com/teacherresources/Interactive/teaching-hardyweinberg-in-the-classroom/tr10630.tr (3) Stanhope, J. Hardy Weinberg Equilibrium. http://www.accessexcellence.org/AE/AEPC/ WWC/1994/hwintro.php (4) The teacher friendly guide to evolution: Hardy-Weinberg Equilibrium. http:// bivalves.teacherfriendlyguide.org/index.php? option=com_content&view=article&id=30:har dy-weinbergequilibrium&catid=27&Itemid=126 SUGGESTED VIDEO:

http://www.brightstorm.com/test-prep/apbiology/ap-biology-videos/hardy-weinbergequilibrium/

80

General Biology 2

180 MINS

Lesson 10: Evolution and Origin of Biodiversity: Patterns of Descent with Modification

LESSON OUTLINE

Content Standard

The learners demonstrate an understanding that organisms exhibit patterns of descent with modification from common ancestors (also known as evolution) and that evolution can account for the organismal diversity observed today.

Introduction Quick Review

5

Motivation

Classifying Animals


Instruction

Species

115


Practice

Activity

20

Enrichment

Film Viewing

20

The learners shall be able to show patterns of descent with modification from common ancestors to produce the organismal diversity observed today.

Evaluation

Quiz

STEM_BIO11/12-IIIc-g-10

Materials

•

present a short skit or play to illustrate modes of speciation

Learning Competency

15

5


Photographs of different species of plants and animals showing the various isolating mechanisms and the different modes of speciation


Resources

•

define species according to the biological species concept;

•

distinguish the various types of reproductive isolating mechanisms that can lead to speciation;

•

discuss the different modes of speciation; and

•

explain how evolution produce the tremendous amount of diversity among organisms.

(1) Freeman, S. Biological Science. 3rd ed. 2008. California: Pearson Benjamin Cummings. pp. 503-525. (2) Reece, JB, LAUrry, ML Cain, S Wasserman, PV Minorsky, RB Jackson. Campbell Biology. th9 ed. 2014. Illinois: Pearson Education Inc. pp. 480-499. (3) Russell PJ, SL Wolfe, PE Hertz, C Starr, B Mc Millan. Biology: the Dynamic Science. 2008. California: Brooks/Cole CENGAGE Learning. pp. 419-439.



Teacher Tip:

Quick Review

Let your learners recall the mechanisms that cause changes in gene frequencies.

1. Give a quick review of the different mechanisms that bring about changes in the population and ultimately lead to evolution.

MOTIVATION (15 MINS) Classifying Animals

1. Ask your learners to give an organism which can be an animal or a plant species. 2. Ask them further if they had seen different kinds or variants of this species and also other species which look like them because they are related. An example is the cat family where lion, tiger, cheetah, etc. belong. 3. Then tell them that the lesson is about how different kinds of organisms or species are produced over time.

INSTRUCTION (115 MINS) Species

1. Define species according to the biological species concept. Ernst Mayer’s definition: “Species are groups of interbreeding natural populations that are reproductively isolated from other such groups.” 2. Discuss the reproductive isolating mechanisms A. Pre-zygotic isolation mechanisms prevent fertilization and zygote formation. – potential mates occupy different I. geographic or ecological or habitat isolation areas or habitats thus, they never come in contact – different groups may not be reproductively mature II. temporal or seasonal isolation at the same season, or month or year – patterns of courtship are different III. behavioral isolation – differences in reproductive organs prevent successful IV. mechanical isolation interbreeding – incompatibilities between egg and sperm prevent fertilization V. gametic isolation 82

Teacher Tip: 1. Take note that there are different species concepts but the best used and most popular among biologists is the biological species concept. 2. All reference books in General Biology gives examples of the occurrence of the isolating mechanisms in different organisms and also specific examples of the three models of speciation. To make things more interesting it will help to show photographs of the species to your learners. You may download the photographs or illustrations from the internet using google images. 3. Give examples of organisms or instances for each reproductive isolating mechanism. Think of local examples.

B. Post-zygotic isolation mechanisms allow fertilization but nonviable or weak or sterile hybrids are formed. – fertilized egg fails to develop past the early embryonic stages I. hybrid inviability II. hybrid sterility– hybrids are sterile because gonads develop abnormally or there is abnormal segregation of chromosomes during meiosis III. hybrid breakdown- F1 hybrids are normal, vigorous and viable, but F 2 contains many weak or sterile individuals 3. Let your learners recall the different genetic mechanisms that can change gene frequencies. Discuss with them that in the presence of a reproductive isolating mechanism, genetic drift, natural selection, mutation and gene flow are free to operate on the population. These will lead to genetic divergence and ultimately to species formation or speciation. 4. Discuss the modes of speciation: A. Allopatric speciation or geographic speciation (allo – other, patric – place; ‘other place’) occurs when some members of a population become geographically separated from the other members thereby preventing gene flow. Examples of geographic barriers are bodies of water and mountain ranges. (sym – same, patric – place; ‘same place’) - occurs when members of B. Sympatric speciation a population that initially occupy the same habitat within the same range diverge into two or more different species. It involves abrupt genetic changes that quickly lead to the reproductive isolation of a group of individuals. Example is change in chromosome number (polyploidization). (para – beside, patric – place; ‘beside each other’) – occurs when C. Parapatric speciation the groups that evolved to be separate species are geographic neighbors. Gene flow occurs but with great distances is reduced. There is also abrupt change in the environment over a geographic border and strong disruptive selection must also happen. 5. You may show the following diagram to differentiate the three models of speciation. 6. You can wrap up your lecture by mentioning that present-day species evolved from earlier species and that the relatedness of organisms is the result of common ancestry. This can be

supported by morphological and anatomical data, homology, biogeography, DNA and protein sequences (molecular data), and embryology. All these evidences of evolution (descent with modification) will be discussed in a separate topic.

PRACTICE (20 MINS) Activity

Based on the descriptions let your learners identify the given isolating mechanisms: 1. Two species of garter snakes live in the same region but one lives in water and the other on land 2. Two species of meadowlarks with different mating songs 3. Two species of trout that breed in different seasons 4. Mule is the sterile offspring of a horse and a donkey 5. Two species of plants flower at different months

84

Based on the descriptions let your learners identify the mode of speciation: 6. The hemp nettle, Galeopsis tetrahit is a tetraploid found to thrive in the same area as two other diploids species, Galeopsis pubescens and Galeopsis speciosa. 7. The Panama porkfish, Anisotremus taeniatus, found in the Pacific Ocean is morphologically similar to the porkfish, Anisotremus virginiacus, found in the Caribbean Sea are separated by a land bridge between North and South America called the Isthmus of Panama. 8. The Siberian lesser black-backed gull, lesser black-backed gull and herring gull are all found in the Arctic region. The lesser black-backed gull interbreeds with the Siberian lesser black-backed gull but not with the herring gull.

ENRICHMENT (20 MINS) Film Viewing

1. Show a short film (~15 minutes) about the “The Beak of the Finch” made by the Howard Hughes Medical Institute. The film can be streamed from the HHMI Biointeractive website http://www.hhmi.org/biointeractive/origin-species-beak-finch) or through YouTube h( ttps://www.youtube.com/ (watch?v=mcM23M-CCog ).

EVALUATION (5 MINS) You may give a quiz about this topic. Here are some sample questions. 1. Which of the following statements about biological species is(are) correct? I. Biological species is a group of individuals whose members interbreed with one another. II. Biological species are the model used for grouping extinct forms of life. III. Members of biological species produce viable, fertile offsprings. A. I only B. II only C. I and III D. II and III E. I, II, and III

Answer Key: 1. C 2. B 3. B 4. A 5. C

Resources

2. The following isolating mechanisms prevent fertilization and formation of zygote except A. Temporal isolation

PAPERS THAT ARE AVAILABLE ONLINE:

(1)

B. Hybrid breakdown C. Gametic isolation D. Ecological isolation

(2)

E. Behavioral isolation For numbers 3-5, use the following choices:

(3)

A. Allopatric speciation B. Sympatric speciation C. Parapatric speciation

(4)

3. Occurrence of abrupt genetic change cause reproductive isolation between groups of individuals. 4. Occurs when populations are separated by a geographic barrier. 5. Abrupt change in the environment over a geographic border and strong disruptive selection affects gene flow between neighboring populations.

(5)

Filson, R.P. Island Biogeography and Evolution: Solving a Phylogenetic Puzzle with Molecular Genetics. Available at http:// www.ucmp.berkeley.edu/fosrec/ Filson.html Flammer, L., J. Beard, C.E. Nelson, & M. Nickels. 1998. ENSIWEB. Evolution/Nature of Science Institutes. Available at http://www.indiana.edu/ ~ensiweb/home.html Flammer, L. Quick Speciation Activity. Available at http://www.indiana.edu/ ~ensiweb/lessons/ quick.speciation.html A Step in Speciation: The Analysis of Field Observations of the California Salamander. Ensantina eschschsoltzii. Available at http://www.indiana.edu/ ~ensiweb/lessons/ quick.speciation.html National Academy of Sciences. Investigating Common Descent: Formulating Explanations and Models (Grades 9-12). Available at the website of the Smithsonian National Museum of Natural History http:// humansrcins.si.edu/education/ lesson-plans/investigating-commondescent-formulating-explanationsand-models-grades-9-12

SUGGESTED VIDEO:

The Origin of Species: The Beak of the Finch. Video is available at the Biointeractive website of the Howard Hughes Medical Institute (HHMI) http:// www.hhmi.org/biointeractive/srcinspecies-beak-finch 86

General Biology 2

Lesson 11: Development of Evolutionary Thought LESSON OUTLINE

Content Standard

The learners will be able to appreciate and understand the events, people and their contributions in the development of evolutionary thought. Performance Standard


Introduction Own Definition of Evolution

5

Motivation

Schema Building

15

Instruction

Lecture: Evolutionary Thought

50

Flash Cards

20

Film Viewing Quiz

30 10

make a list of scientists/ people who contributed to early evolutionary ideas Practice

Learning Competency

STEM_BIO11/12-IIIc-g-11

Enrichment Evaluation


Materials


Photographs of different species of plants and animals showing the various isolating mechanisms and the different modes of speciation

The learners shall be able to trace the development of evolutionary thought.

•

enumerate the scientists and cite their respective contributions in the development of evolutionary thought;

•

describe Jean Baptiste Lamarck’s hypothesis on evolutionary change;

•

discuss Charles Darwin’s theory of evolution by natural selection; and

•

explain the Modern Synthesis as the unified theory of evolution

Resources (1) Freeman, S. Biological Science. 3rd ed. 2008. California: Pearson Benjamin Cummings. pp. 503-525. (2) Reece, JB, LAUrry, ML Cain, S Wasserman, PV Minorsky, RB Jackson. Campbell Biology. th9 ed. 2014. Illinois: Pearson Education Inc. pp. 462-470. (3) Russell PJ, SL Wolfe, PE Hertz, C Starr, B Mc Millan. Biology: the Dynamic Science. 2008. California: Brooks/Cole CENGAGE Learning. pp. 401-418.


Teacher Tip: To illustrate evolutionary relationships show pictures of plants or animals that are members of the same genus or family (evolutionarily related). Or you may show a phylogenetic tree with illustrations of the species. The internet is a very good source of illustrations like this. Point out how similar they look like and relate it to the definiti on of evolution.

Own Definition of Evolution

1. Ask learners to make their own definition of evolution

MOTIVATION (15 MINS)

Teacher Tip

Schema Building

1. Ask your learners what they know about evolution. This will give you an idea about the current perception of your learners about evolution, which to some remains to be a controversial topic.


It is highly probable that you will get answers about creationism vs evolution. Make sure that you read well so that you may be able to provide answers to their questions.

Teacher Tip

Lecture: Evolutionary Thought

1. Give a lecture about early scientists who contributed in shaping and developing evolutionary thought. Put emphasis on the following: A. Carolus Linnaeus – order in the diversity of life; hierarchy of taxonomic categories B. Thomas Malthus – ‘Essay on the Principle of Population’ C. Georges Cuvier – fossils, paleontology and the theory of Catastrophism D. James Hutton – theory of Gradualism E. Charles Lyell – principles of geology 2. Give a lecture on Jean Baptiste Lamarck’s theory on evolutionary change A. Principle of use and disuse B. Inheritance of acquired characteristics 3. Describe Charles Darwin’s voyage and his observations that led him to write ‘The Origin of Species’ 88

Use the internet to get images or pictures of the following: A. People that will be mentioned in your lecture. This would personify the scientists and will better familiarize the learners with them. B. Images that exhibit Lamarck’s theory (e.g. giraffe) C. Map of the Galapagos Islands and organisms observed by Darwin

A. Voyage of the Beagle and organisms in the Galapagos islands B. Darwin’s reflections after his voyage C. Darwin’s use of common knowledge D. Writing and publication of ‘The Origin of Species ’

Take note that it is not only Charles Darwin who is credited in the development of the theory of evolution through natural selection. Another scientist, Alfred Russel Wallace from his exploration of the Amazon Basin is considered as the co-discoverer of the theory of evolution by natural selection.

4. Explain to the class Darwin’s theory of evolution by natural selection. Make sure that you will be able to include the following in your discussion: A. Descent with modification B. Existence of variation C. Struggle for existence D. Artificial selection, natural selection and adaptation

The table on the upper right part is from Russell et al. (2008; page 410) is a summary of Darwin’s observations and inferences.

5. Give a lecture on the Neo-Darwinian theory or Modern Synthesis which is a unified theory of evolution. It should include the contributions of the following to substantiate Darwin’s idea about evolution. A. Contribution of Mendelian Genetics B. Birth of Population Genetics C. Use of data from biogeography, comparative morphology, comparative embryology, A. Paleontology, taxonomy, etc.

Take note that the very last portion is somehow an introduction to the next topic about the evidences of evolution.

PRACTICE (20 MINS) Flash Cards

1. With flash cards, allow learners to identify the name of the scientist and his contribution to early evolutionary ideas.

ENRICHMENT (30 MINS) Film Viewing

1. You may ask your learners to watch the following video: The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video posted at YouTube (https:// www.youtube.com/watch? v=XOiUZ3ycZwU)

Teacher Tip: This can be done by the learners on their own time and at home.

Answer Key:

EVALUATION (5 MINS) You may give a quiz about this topic. Here are some sample questions.

1. Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of A. Evolution. B. The fossil record. C. Uniformitarianism. D. The srcin of new species. E. Natural selection. 2. Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus? A. Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future. B. Populations tend to increase at a faster rate than their food supply normally allows. C. Earth changed over the years through a series of catastrophic upheavals. D. The environment is responsible for natural selection. E. Earth is more than 10,000 years old. 90

1. 2. 3. 4. 5. 6. 7.

B B C E C A C

3. In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of A. Cuvier. B. Hutton. C. Lamarck. D. Darwin. E. Lyell. 4. Which of the following ideas is not included in Darwin’s theory? A. All organisms that have ever existed arose through evolutionary modifications of ancestral species. B. The great variety of species live today resulted from the diversification of ancestral species. C. Natural selection drives some evolutionary change. D. Natural selection preserves favorable traits. E. Natural selection eliminates adaptive traits. 5. Which of the following statements is not compatible with Darwin’s theory? A. All organisms have arisen by descent with modification. B. Evolution has altered and diversified ancestral species. C. Evolution occurs in individuals rather than in groups. D. Natural selection eliminates unsuccessful variations. E. Evolution occurs in because some individuals function better than others in a particular environment.

6. Which of the following must exist in a population before natural selection can act upon that population? A. Genetic variation among individuals B. Variation among individuals caused by environmental factors C. Sexual reproduction D. Three of the responses are correct. E. Two of the responses are correct. 7. Which of the following does not contribute to the study of evolution? A. Population genetics B. Inheritance of acquired characteristics C. Fossil records D. Comparative embryology E. Comparative morphology

General Biology 2

120 MINS

Lesson 12: Evidences of Evolution Content Standard

The learners demonstrate understanding of evidences of evolution.

LESSON OUTLINE


Introduction Review of Previous Lesson


5

•

illustrate the evidences of evolution

Motivation

Videos on Fossil Evidences

•

explain how the fossil record has aided in the development of the theory of evolution

Instruction

Report

30

5

Practice

Giving Evidences for Evolution

10

The learners explain evidences of evolution (e.g. fossil record, biogeography, DNA/ protein sequences, homology and embryology (STEM_BIO11/12-IIIc-

Enrichment

Evidences to Support Evolution in Recent Times

10

g-12) Specific Learning Outcomes

Materials

Learning Competency

Downloaded videos, internet sources, worksheets, laboratory sheets


describe the evidences to support evolution and

•

explain some modern evidences of evolution

Resources (1) Evidence for Evolution: http://necsi.edu/projects/evolution/evidence/ evidence_intro.html (Retrieved 09/08/15) (2) Evidence of Evolution: https://www.boundless.com/biology/textbooks/ boundless-biology-textbook/evolution-and-the-srcin-of-species-18/ understanding-evolution-124/evidence-of-evolution-498-11724/ (Retrieved 09/08/15) (3) Evidence of Evolution: http://www.classzone.com/science_book/ mls_grade7_FL/508_514.pdf (R etrieved 09/08/15) (4) Evolving Ideas: How Do We Know Evolution Happens http:// www.pbslearningmedia.org/resource/tdc02.sci.life.evo.howhappens/ evolving-ideas-how-do-we-know-evolution-happens/ (5) The Day the Mesozoic Died: The Asteroid That Killed the Dinosaurs — HHMI BioInteractive Video - https://www.youtube.com/watch? v=tRPu5u_Pizk (Retrieved 04/16/16) Additional Resources at the Back

92

INTRODUCTION (5 MINS) Communicate Learning Objectives

1. Introduce the following objectives by asking volunteers to read them aloud. I. I can explain each evidence of evolution. II. I can use scientific evidence to infer relationships among organisms

Teacher Tip: During Darwin’s time, people had b een searching for evidences that will support evolution. Some evidences like fossil and structural similarities were used by scientists to explain evolution. Other evidences were obtained using inferences developed after Darwin’s time.

Guide Questions

1. What evidences did scientists use to support the theory of evolution? 2. What evidences are supported by modern technologies? 3. What recent evidences prove that evolution is taking place?

MOTIVATION (5 MINS)

Alternative

Videos on Fossil Evidences

The following pictures can be shown and the learners are asked to identify the evidence presented.

1. Could a Fossilized Mosquito Resurrect Dinosaurs? (2:36 minutes) - https://www.youtube.com/ watch?v=8kHyNOa7cuc (Retrieved 04/16/16)

1. Fossil of a dinosaur 2. Organisms found in different places (but belong to the same group)

The following videos will be shown to start the lesson, as well as, to review an evidence discussed in the past topic.

2. There’s a Dinosaur that Survived Mass Extinction (1:45 minutes) - https://www.youtube.com/ watch?v=8kHyNOa7cuc (Retrieved 04/16/16) 3. How Dinosaurs Went Extinct? (2:20 minutes) - https://www.youtube.com/watch?v=Y8Ij9xboreA (Retrieved 04/16/16) Guide Questions

1. Is it possible to resurrect the organism (by cloning) whose DNA was sucked by the mosquito? 2. What period did most dinosaurs become extinct? How could a dinosaur possibly escape the fate suffered by other organisms?

3. Vestigial structures in two related organisms 4. DNA sequence in two related organisms 5. Domestication of dogs 6. The case of the peppered moth 7. Antibiotic resistance in bacteria

INSTRUCTION (40 MINS) 1. After showing the introductory videos, tell the learners that are other evidences that are used to support the theory of evolution. 2. The leaders will draw numbers to determine who will report first. 3. The following topics are to be presented by the assigned group. I. Evidence from molecular biology II. Structural evidences: homology, analogy, vestigial structures III. Evidence from biogeography IV. Evidence from embryology 4. Each group will be given 7-10 minutes to present. 5. Other learners must remain quiet and take down notes during each report. 6. The scores by the teacher will be given next meeting. EVIDENCES OF EVOLUTION Evidence from Fossils

Teacher Tip: The topics for reporting should be given 1 – 2 days before to give the learners enough time to research. Four leaders will be chosen and they will be the ones to choose their members. 1. Evidence from molecular biology 2. Structural evidences: homology, analogy, vestigial structures 3. Evidence from biogeography 4. Evidence from embryology The following criteria should be followed in the report: 1. Content- should include the important details about the topic 2. Creativity- must be engaging and interesting 3. Concise- brief and focused 7-10 minutes are allotted for each topic

Fossils are remains of ancient organisms trapped in rocks, tar pits, frozen in ice or embedded in amber. The activities and behavior of ancient life forms also left behind fossil traces (such as footprints, dungs, gastric stones, nests and burrows) which scientists can study. The records found in the rocks show a gradual evolutionary descent from simpler to more complex life forms. Paleontologists use the fossils found in rocks to track the evolutionary history of many organisms. Example:

The ancestors of modern horses were short browsers with diet of broad-leaved plants, shrubs and trees. They had more toes (four in front, three at the back) which prevented them from sinking in the soft, marshy ground. As the climate changed to drier conditions, foliage plants were replaced by grass fields. Those with the characteristics suited for this (tooth structure fit for eating hard, dry grass) survived better. The forced grazers also became runners (with longer leg bones and lesser toes) to be able run more efficiently in the hard ground and to escape from predators. 94

To engage everyone in reporting, the teacher may grade the report and add the points to a future assessment like long test or project. A certain score in the report must be acquired to get the added point in the future assessment. For example, the following may be used as points for the various criteria: Content = 10 Creativity = 10 Conciseness = 5 20 – 25 pts = +3 15 – 20 pts = +2 10 – 15 pts = +1 below 10 = no additional points

Evidence from Structures

Teacher Tip:

Structures in different organisms can be compared to infer common lineage.

The principle of homology illustrated by the adaptive radiation of the forelimb of mammals. All conform to the basic pentadactyl pattern but are modified for different usages. The third metacarpal is shaded throughout; the shoulder is crossed-hatched.

HOMOLOGOUS STRUCTURES are

structures with the same set of bones that presumably evolved from a common ancestor. Theyappear different and may havevaried functions.

(From: https://goo.gl/8yrjdd)

ANALOGOUS STRUCTURES are structures that perform the same function but have very different embryological development or set of structures like bones.

96

Teacher Tip: The wings of the bat are made of skin, hair and bone; the wings of the bird are made of skin, feather and bones; the wings of an insect are made of chitin and bones are absent.

VESTIGIAL STRUCTURES are

structures or attributes that have lost most of its ancestral function in

more recent species.

The human vermiform appendix has lost much of its ancestral functions (distant ancestors ate more vegetation).

Teacher Tip: Other vestigial structures in humans include the following: 1. Tail bone/ coccyx 2. Sinuses 3. Wisdom teeth 4. Muscle in the external ear 5. Erector pili muscles 6. Tonsils 7. Male nipples 8. Palmar grasp reflex of infants 9. Plica semilunaris in the eyelid From: http://goo.gl/9qjcYK

EVIDENCE FROM EMBRYOLOGY

Embryology is the study of the development of an organism from an embryo to its adult form. Common structures are shared in the embryo stage and disappear by the time the embryo reaches the juvenile or adult form.

EVIDENCE FROM MOLECULAR BIOLOGY

Many organisms have similar molecules of life (RNA, DNA, proteins) that suggest descent from a common ancestor with modifications. The near universality of the genetic code reflects an evidence of common ancestry and relatedness and can be inferred from the similarities in the DNA sequences between and among organisms.

Vertebrates have similarities in their embryo forms such as the pharyngeal gill slits and the post-anal tail. In aquatic vertebrates, the gill slits become part of the gills and tails are retained while land vertebrates become covered with skin and some lose the tail in adult forms.

Many organisms have similar molecules of life (RNA, DNA, proteins) that suggest descent from a common ancestor with modifications. The near universality of the genetic code reflects an evidence of common ancestry and relatedness and can be inferred from the similarities in the DNA sequences between and among organisms. Many organisms have similar molecules of life (RNA, DNA, proteins) that suggest descent from a common ancestor with modifications. The near universality of the genetic code reflects an evidence of common ancestry and relatedness and can be inferred from the similarities in the DNA sequences between and among organisms.

Human Beta Chain

0

Gorilla

1

Gibbon

2

Rhesus monkey

8

Dog

15

Horse, cow

25

Mouse

27

Evidence from Biogeography

Gray Kangaroo

38

Biogeography is the study of geographical distribution of fossils and living organisms. Organisms usually arise in areas where similar forms already exist. Similar organisms may also be found in different locations which could mean that the two places were previously connected.

Chicken

45

PRACTICE (10 MINS) Identify the evidence shown by the picture and explain how it supports evolution.

98

Frog

67

Lamprey

125

Sea slug

127

Soybean

124

Given the evidence, the learner should be able to explain how it supports evolution.

Evidence from homologous structures - structures with different functions but the same ancestral srcin

Evidence from fossils - shows the changes in the organism through time and how recent organisms compare with it

Evidence from embryology - show that related organisms have similar structures in their earlier forms; in some, the function is lost and the structure becomes vestigial

Evidence from biochemistry - show similarities in the molecules of life such as proteins, DNA and RNA; similarities in the sequence reflects relationship

(taken from http://goo.gl/0W09FY)

FURTHER DISCUSSION

Teacher Tip:

Evidences to support that Evolution is happening in recent times

Sometimes the learners can’t visualize something that happened millions of years ago or something that they can’t see with their naked eyes. They might ask if evolution can happen within their lifetime.

1. Antibiotic Resistance in Bacteria 2. Pesticide Resistance 3. Variation in the Beaks of Finches 4. Industrial Melanism in Peppered Moth

At this point, the teacher can discuss some evidences that evolution can be proven to be going on in recent years.

5. Domestication of Dogs 6. Cultivation of Crops

Worksheets and other information can be acquired from the following sites.

ASSIGNMENT

1. How do we infer relationships among organisms given the various evidences of evolution? 2. Download and accomplish with a partner the Evidence of Evolution worksheet found in this site. 3. TCSS Biology: Unit 4- Evolution Information - http://www.msfta.org/cms/lib6/FL02001163/ Centricity/Domain/54/Evidence%20of%20Evolution.pdf - (last accessed 04/17/16, 10:36am) 4. The teacher can also download the pdf worksheet and provide the class a hard copy or post the drawings on the board and ask questions as part of class recitation.

For antibiotic and pesticide resistance TCSS Biology: Unit 4- Evolution Information http://goo.gl/0W09FY (last accessed 04/17/16, 10:36am) For the variation in the beaks of finches Battle of the Beaks: http://www.sepa.duq.edu/darwin/pdf/ UniqueBeakPhysique.pdf (last accessed 04/17/16, 11:09am) Famous Beaks: https://www.nsta.org/publications/press/extras/ files/virus/Virus-Activity5.pdf (last accessed 04/17/16, 11:09am) The Beaks of Finches http://www.allhallows.org/ourpages/auto/ 2015/5/26/53452671/biolab18.pdf (last accessed 04/17/16, 11:11am) Peppered Moth Simulation http://biologycorner.com/worksheets/ pepperedmoth.html (last accessed 04/17/16, 11:17am)

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Additional Resources:

Fossils Evidence

•

http://www.nicholls.edu/biol-ds/biol155/Lectures/Evidence%20for%20Evolution.pdf

• http://goo.gl/Hq7wAO • http://web.iitd.ac.in/~amittal/SEH_Evolution_Evidence.pdf •

http://evolution.berkeley.edu/evolibrary/article/evograms_03

• http://creation.com/the-evolution-of-the-horse Structural Evidence

•

https://www.boundless.com/biology/textbooks/boundless-biology-textbook/evolution-and-the-srcin-of-species-18/evidence-ofevolution-129/homologous-structures-523-13101/

•

http://sdrdbiology.blogspot.com

Embryological Evidence

•

http://www.nicholls.edu/biol-ds/biol155/Lectures/Evidence%20for%20Evolution.pdf

Biogeographic Evidence

• https://opencurriculum.org/5404/evidence-for-evolution/ Evidence for Evolution : http://necsi.edu/projects/evolution/evidence/evidence_intro.html (Retrieved 09/08/15) Evidence of Evolution : https://www.boundless.com/biology/textbooks/boundless-biology-textbook/evolution-and-the-srcin-of-species-18/ understanding-evolution-124/evidence-of-evolution-498-11724/ (Retrieved 09/08/15) Evidence of Evolution : http://www.classzone.com/science_book/mls_grade7_FL/508_514.pdf (Retrieved 09/08/15) Evolving Ideas: How Do We Know Evolution Happens http://www.pbslearningmedia.org/resource/tdc02.sci.life.evo.howhappens/evolvingideas-how-do-we-know-evolution-happens/

General Biology 2

120 MINS

Lesson 13: Evolutionary Relationships of Organisms LESSON OUTLINE

Introduction Communicating Learning Objectives Content Standard

Motivation

The learners demonstrate an understanding as to how organisms are related to each other. Performance Standard


describe the criteria used to establish relationships among groups of organisms

Review

5 15

Instruction Worksheets and Practice

70

Evaluation

Cladogram of Horses

20

Enrichment

Comparison of Wings

10

Materials

Papers, pens, colored pens, worksheet, diagrams The learners should be able to infer evolutionary relationships among Resources organisms using the evidences of evolution (STEM_BIO11/12-IIIc-g-13 ) (1) Evidence for Evolution: http://necsi.edu/projects/evolution/evidence/ Learning Competency

evidence_intro.html (Retrieved 09/08/15) (2) Evidence of Evolution: https://www.boundless.com/biology/textbooks/ boundless-biology-textbook/evolution-and-the-srcin-of-species-18/ recognize how comparisons of similarities and differences can understanding-evolution-124/evidence-of-evolution-498-11724/ suggest evolutionary relationships; (Retrieved 09/08/15) explain the significance of using multiple lines of evidence to identify (3) Evidence of Evolution: http://www.classzone.com/science_book/ mls_grade7_FL/508_514.pdf (Retrieved 09/08/15) evolutionary relationships; (4) Molecular Evidence for Evolutionary Relationship http:// infer the degree of relationships among organisms based on the www.pbslearningmedia.org/resource/tdc02.sci.life.gen.lp_cytoc/ amino acid sequence in the cytochrome c molecule; molecular-evidence-for-evolutionary-relationships/ compare four species of horses by measuring structures in their hind (5) Taxonomy: Classifying Life http://www.biology-pages.info/T/ legs; and Taxonomy.html (Last accessed 04/21/16, 3:10pm) (6) Activity: Comparing Horse Hooves and Teeth Fossils http:// differentiate various hominids by describing their physical features. www.amnh.org/content/download/39770/581405/file/horsefossil.pdf (Last accessed 04/23/16, 9pm)


At the end of the lesson, the learners will be able to: • • • • •

102


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can explain each evidence of evolution. II. I can use some evidences to infer relationships among organisms

MOTIVATION (15 MINS) Review

1. Ask learners to recall evidences of evolution from the previous lessons.

INSTRUCTION AND PRACTICE (70 MINS) 1. Distribute the worksheets to learners. Let them work with their groupmates. I. Molecular Connection Worksheet II. How Do Fossils Show Change? 2. Tell them to start at once in order for them to finish the activity on time. 3. Move around to check on each group. 4. You may ask learners on the spot some questions about the activity to check if they understand what they are doing. 5. The members may divide tasks in order to finish the activity. In case they are not able to finish, they can continue working after class and submit the paper next meeting. INFERRING RELATIONSHIPS FROM EVIDENCES OF EVOLUTION

Living things share some biomolecules which may be used to prove relationships. These chemicals include DNA and proteins. The building blocks of these chemicals may be analyzed to show similarities and differences among organisms. The more similarities, the closer the relationships. One of these is the protein cytochrome-c, an important enzyme found in virtually all organisms. It is a highly conserved protein which functions in the electron transport chain system of the

Teacher Tip: Laboratory groups should have been assigned at the start of the school year. Each learner must take a role in each group (leader, secretary, materials manager). The teacher must see to it that all members of the group contribute to the task. Allocate the time properly. Refer to the following sites that offer activities which can be modified for this lesson: •

The Molecular Connection: http://goo.gl/ Kfivwx (Last accessed 04/21/16, 8:15am) http://goo.gl/aeoEvu (answer key- Last accessed 04/21/16, 8:15am)

•

Cytochrome C Comparison Lab http:// www.indiana.edu/~ensiweb/lessons/ molb.ws.pdf (Last accessed 04/25/16, 2:30pm) http://www.indiana.edu/~ensiweb/ cytows.r.pdf (answer key-Last accessed 04/25/16, 2:30pm)

•

How Do Fossils Show Change https:// www.nps.gov/flfo/learn/education/upload/ unit3lesson10.pdf (Last accessed 04/25/16, 3:35pm)

mitochondria which is needed for the release of energy from food. It also performs a role in apoptosis (programmed cell death) by being released into the cytosol activating the events of cell death. The diagram below shows the structure of cytochrome c and its location in the mitochondrial inner membrane.

Teacher Tip: Laboratory groups should have been assigned at the start of the school year. Each learner must take a role in each group (leader, secretary, materials manager). The teacher must see to it that all members of the group contribute to the task. Allocate the time properly. Refer to the following sites that offer activities which can be modified for this lesson:

The learners will compare the amino acid sequences of this protein for different animals. From this information they will infer the evolutionary relationships between the animals. Then they will compare this molecular data to a cladogram, a branching diagram of possible evolutionary relationships based on the anatomical structures of the animals. There are 104 amino acids in the human cytochrome c, 37 of which have been found at the same position in every cytochrome c that has been sequenced. The molecules are assumed to have descended from a primitive microbial cytochrome that existed over two billion years ago. The data can then be tabulated to show the number of differences. A cladogram, or branching tree can then be made to show the relationship among the organisms. 104

•

The Molecular Connection: http://goo.gl/ Kfivwx (Last accessed 04/21/16, 8:15am) http://goo.gl/aeoEvu (answer key- Last accessed 04/21/16, 8:15am)

•

Cytochrome C Comparison Lab http:// www.indiana.edu/~ensiweb/lessons/ molb.ws.pdf (Last accessed 04/25/16, 2:30pm) http://www.indiana.edu/~ensiweb/ cytows.r.pdf (answer key-Last accessed 04/25/16, 2:30pm)

•

How Do Fossils Show Change https:// www.nps.gov/flfo/learn/education/upload/ unit3lesson10.pdf (Last accessed 04/25/16, 3:35pm)

IMAGES FROM: • From: https://en.wikipedia.org/wiki/ Cytochrome_c • From: http://goo.gl/3bcQva

http://www.indiana.edu/~ensiweb/cytows.r.pdf

http://www.indiana.edu/~ensiweb/cytows.r.pdf

Basic features (cells and anatomical structures) can also be used to infer relationship among organisms. The types of cells (prokaryotic or eukaryotic), presence and number of limbs, presence of wings or hair can be compared to show relationships which can be plotted in a cladogram. WORKSHEET FOR PRACTICE C EL LS

L EG S

LE 6 GS

W IN G S

WORM SPIDER CARPENTER ANT (BLACK) FLY

Place the organisms above in the cladogram below and indicate the traits that made the organisms different from each other.

Vertebrates possess common structures (pharyngeal gill slits, notochord, dorsal nerve cord, and post-anal tail) which are present in embryo stage and are lost, modified or become vestigial in adult forms. The presence of these structures implies descent from a common ancestor. A complex cladogram can then be created to show the positions of the organisms in the evolutionary tree.

Teacher Tip: The dry laboratory will serve as a guide for learners to understand better how the evidences can be used to infer relationships among organisms. 106

EVALUATION (20 MINS) The leg structures of modern-day horses can be compared with those of fossilized remains. Worksheet

Compare the leg structures and tooth structures of the horse species shown below. A. Color the toe bones red, marked with an x. B. Color the foot bones blue, marked with a y. C. Color the ankle bones green, marked with a w. D. Color the heel bones yellow, marked with a z. After accomplishing the worksheet, make a cladogram of the horse. https://www.nps.gov/flfo/learn/education/upload/unit3lesson10.pdf

EQ U U S

NUMBER OF TOES NUMBER OF TOE BONES NUMBER OF FOOT BONES NUMBER OF ANKLE BONES NUMBER OF HEEL BONES TOTAL NUMBER OF FOOT BONES LENGTH OF FOOT (MEASURE IN SET DIAGRAM, IN MM) GEITH OF TEEH, MM

H Y D R A CO T H E R I U M

M Y OH IP P U S

M ET Y C H IP P U S

Teacher Tip:

Additional Questions

1. What environmental changes happened from the time of the earliest to the most recent horses? 2. How did the species adapt through time?

This activity was taken from http://goo.gl/5dALps (Last accessed: 04/24/16, 4pm) Use this worksheet to evaluate the learners in inferring relationships from evidences.

ENRICHMENT (10 MINS) 1. This may be given as a take home assignment 2. Compare and contrast the two structures. 3. What do scientists infer from the similarities between these two structures? 4. What do scientists call such similar structures? 5. Describe how DNA evidence might be used to confirm scientists’ conclusions about any relationship between the bird and the seal.

Analyzing Cladograms: http://www.isd622.org/cms/lib07/MN01001375/ Centricity/Domain/718/ Learning_Target_4.6_Cladograms.pdf (Last accessed 04/24/16, 4:47pm)

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General Biology 2

180 MINS

Lesson 14: Systematics Based on Evolutionary Relationships: Tree of Life and Systematics LESSON OUTLINE


20

The learners demonstrate an understanding of Basic Taxonomic Concepts and Principles, Description, Nomenclature, Identification and Classification.

Motivation

Think Pair Share

30

Instruction

Group Work

65


Practice

Collaborative Learning through 3D Tree

50

Content Standard


demonstrate understanding of basic taxonomic principles.

Learning Competency

The learners should be able to Explain how the structural and developmental characteristics and relatedness in DNA sequences are used to classify living things (STEM_BIO11/12IIIh-j-14)

Building Enrichment Inquiry and Research

15

Materials Pieces of paper, wires, cartolina, colored papers, pen, markers, scissors, glue. They may bring reading materials pertaining to the tree of lif e or some materials from the internet concerning Mammalian and Human Evolution.



describe the multiple lines of evidence used to infer evolutionary relatedness;

•

discuss how anatomical, developmental and relatedness in DNA sequences are used as evidence to infer the relatedness of taxa; and

•

explain that classification is based on evolutionary relatedness

Resources (1) Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology.10 th edition. San Francisco, California, USA: Pearson Education Inc.; 2014. p.465, p. 508, pp.510-514, pp. 536(2) Eric Lee. 2004. Making 3D Models of the Tree of Life. http:// toweb.org/online contributors/app?service-external/ ViewTreehouses&sp=2974. 24 August 2015. (3) The family tree. http://evolution.berkeley.edu/evolibrary/article/ evo_03.24 August 2015


Teacher Tip: Here are some definition of terms:


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud)

Phylogeny-the evolutionary history of a species or group of species

I. I can discuss multiple lines of evidence used to infer evolutionary relatedness. II. I can discuss how anatomical, developmental and relatedness in DNA sequences are used as evidence to infer the relatedness of taxa.

Systematics- the study of the kinds and diversity of organisms and of any and all relationships among them.

III. I can explain that classification is based on evolutionary relatedness.

Homology-similarity due to shared ancestry

Review

1. Say, “Look around you and realize the enormous diversity of life you can observe. Life on earth is amazing and over the last 3.7 billion years or so, living organisms on Earth have diversified and adapted to almost every environment. Though life is so diverse, all living organisms do share certain similarities. Systematists use data ranging from fossils to molecules and genes to infer evolutionary relationships. These information are used to construct the phylogenetic tree of life. TRIVIA: A

Window to Early Life? An instrument on the research submarine Alvin samples the water around a hydrothermal vent in the Sea of Cortes. More than 1.5km below the surface, the vent releases hydrogen sulfide and iron sulfide, which react and produce pyrite (fool’s gold) and hydrogen gas. Prokaryotes that live near the vent use the hydrogen as an energy source. Such environments are among the most extreme in which life exists today, and some researchers favor the hypothesis that life may have begun in similar regions of early Earth.

2. Ask learners to define the following biological terms in their own words: I. homology II. molecular clock III. phylogeny IV. systematics

110

Molecular clock - a yardstick for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates

3. Stress the importance of understanding how trees are constructed and how multiple lines of evidence are used to infer evolutionary relatedness.

Teacher Tip: Ask learners to work in pairs and then discuss the significance of the activity and why such specific question was asked.

4. Outline of topics: I. multiple lines of evidence used to infer evolutionary relatedness II. anatomical, developmental and relatedness in DNA sequences as evidences to infer the relatedness of taxa III. classification is linked to phylogeny IV. classification as basis of evolutionary relatedness

MOTIVATION (30 MINS) Think Pair Share

1. Instruct your learners to work with a partner. Ask “What makes you unique and what makes you similar?” Discuss this with your partner. Ask them to write in a piece of paper the information they shared with their partners and take note of the features (e.g. physical or genetic) that makes them unique and similar to each other. 2. Ask for a volunteer to present in class what they have discussed in pairs. 3. Explain to learners, “The foremost question that every systematist would ask himself is what makes one unique and what makes one similar to one another. One of the major tasks of systematics is to determine by means of comparison what the unique properties of each species and higher taxon are. Another is to determine what properties certain taxa have in common and the biological causes of the differences or shared characters. In this way, one begins to understand the relatedness and relationships of organisms in the tree of life. Systematics has been used to construct the evolutionary relationship of life’s diverse forms. In recent years, we have gained insight into the very deepest branches of the tree of life through molecular systematics.

Systematics is the study of the kinds and diversity of organisms and of any and all relationships among them. Tracing phylogeny is one of the goals of systematics; hence, it is considered as the study of biological diversity in an evolutionary context. Systematists use data ranging from fossils to molecules and genes to infer evolutionary relationships. These information enable biologists to construct a comprehensive tree of life that will continue to be refined as additional data are collected.

NOTE: Systematics encompasses

following fields: a. biodiversity b. evolutionary biology c. phylogenetics d. taxonomy

the


Teacher Tip:

Group Work: Construction of 3D models of the Tree of Life

1. Say, “It is difficult to grasp the tree of life. oT understand this, we need to construct 3-D models One model would show the big picture, including the 3 Domains of Life: Bacteria, Archaea, and Eukarya along with themajor divisions of eachdomain. However, it is a tedious process of making (such a big tree!). For the sake of this exercise and just to give us the feeling on how to go about in constructing trees, we will construct a 3-D model of the phylogenetic tree of life (see figure below). 2. Divide the class into two groups. The task is to create a 3-D model of the tree of life using the listed materials. This 3-D model will help learners understand that all organisms evolved from 3 lineages: Archaea, Bacteria and Eukarya.

Beforehand, ask learners to bring materials when they come to class (wires, cartolina, colored papers, pen, markers, scissors, glue); They may bring reading materials pertaining to the Tree of Life or some materials from the internet concerning Human Evolution

Ask the learner to make a personal review on the multiple lines of evidence used to infer evolutionary relatedness. Explain the rationale of the activity.

https://upload.wikimedia.org/wikipedia/commons/b/b7/PhylogeneticTree.png 112

Lines of evidence to infer evolutionary relationships :

Teacher Tip:

1. Fossil evidence

Discuss to learners different lines of evidence used to construct trees.

2. Homologies- Similar characters due to relatedness are known as homologies. Homologies can be revealed by comparing the anatomies of different living things, looking at cellular similarities and differences, studying embryological development, and studying vestigial structures within individual organisms. Each leaf has a very different shape and function, yet all are homologous structures, derived from a common ancestral form. The pitcher plant and Venus' flytrap use leaves to trap and digest insects. The bright red leaves of the poinsettia look like flower petals. The cactus leaves are modified into small spines which reduce water loss and can protect the cactus from herbivory. Another example of homology is the forelimb of tetrapods (vertebrates with legs). - Frogs, birds, rabbits and lizards all have different forelimbs, reflecting their different lifestyles. But those different shareseen the same set of - thetransitional humerus, the radius, and the ulna. , Eusthenopteron These areforelimbs the sameallbones in fossils of bones the extinct animal, which demonstrates their common ancestry. Organisms that are closely related to one another share many anatomical similarities. Sometimes the similarities are conspicuous, as between crocodiles and alligators, but in other cases considerable study is needed for a full appreciation of relationships. Developmental biology - Studying the embryological development of living things provides clues to the evolution of present-day organisms. During some stages of development, organisms exhibit ancestral features in whole or incomplete form.

3. Biogeography - the geographic distribution of species in time and space as influenced by many factors, including Continental Drift and log distance dispersal. 4. Molecular clocks help track evolutionary- time The base sequences of some regions of DNA change at a rate consistent enough to allow dating of episodes in past evolution. Other genes change in a less predictable way.

See Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology.10 th edition. San Francisco, California, USA: Pearson Education Inc. Chapter 26: Phylogeny and the Tree of Life

Classification is linked to Phylogeny

Sources:

5. Biologists use phylogenetic trees for many purposes, including: I. Testing hypotheses about evolution

•

II. Learning about the characteristics of extinct species and ancestral lineages III. Classifying organisms

•

•

The connection between classification and phylogeny is that hierarchical classification is reflected in the progressively finer branching of phylogenetic trees. The branching patterns in some cases match the hierarchical classification of groups nested within more inclusive groups. In other situations, however, certain similarities among organisms may lead taxonomists to place a species within a group of organisms (for example genus or family) other than the group to which it is closely related. If systematists conclude that such mistake has occurred, the organism may be reclassified (that is placed in a different genus or family) to accurately reflect its evolutionary history.

•

•

https://upload.wikimedia.org/ wikipedia/commons/3/34/ Snow_Leopard_(PSF).png http://s3.amazonaws.com/ thumbnails.illustrationsource.com/ huge.101.507103.JPG http://quaker-animals.co.uk/wpcontent/uploads/2013/04/otterdrawing.jpg http://s3.amazonaws.com/ thumbnails.illustrationsource.com/ huge.102.510229.JPG http://comps.canstockphoto.com/canstock-photo_csp6538507.jpg

The Connection between Classification and Phylogeny. Hierarchical classification can reflect the branching patterns of phylogenetic trees. This tree traces possible evolutionary relationships between some of the taxa within order Carnivora, itself a branch of class Mammalia. The branch point (1) represents the most recent common ancestor of all members of the weasel (Mustelidae) and dog (Canidae) families. The branch point (2) represents the most recent common ancestor of coyotes and gray wolves.

114

PRACTICE (50 MINS)

Teacher Tip:

Collaborative Learning Groups through 3D Tree Building

Practice more on constructing a branch on the tree of Life. This time work with Class Mammalia.

1. Learners will still work as a group 2. The task is to create a 3-D model of a branch of the Tree of Life and tell multiple lines of evidence that converge to tell the story of Mammalia as a branch in the big Tree of Life. Mammalia(Mammals) 22 Prototheria Monotremata(Egg-laying mammals) Ornithorhynchidae (Platypus) Tachyglossidae (Echidnas) Theria Eutheria(Placentals) Afrotheria(Golden mole, hyrax, shrew, elephant, manatee, aardvark) Carnivora(Dog, cat, mongoose, hyena, skunk, otter, weasel, bear, pinniped) Cetartiodactyla (Whale, dolphin, hippopotamus, ruminantes, pig) Chiroptera(Bats) Dermoptera(Flying lemur) Edentata(Sloth, armadillo, anteater) Insectivora(Hedgehog, shrew, moles) Lagomorpha(Rabbits and hares) Perissodactyla(Odd-toed ungulates: horses, zebra, rhinoceros, tapir) Pholidota(Pangolins) Primates(Old and New World monkeys, hominid, gibbon, lemur) Rodentia(Rats, mice, guinea pig, chinchilla, capybara, porcupine, squirrel) Scandentia(Tree shrews)

Metatheria(Marsupials) Dasyuromorphia(Marsupial mice, Tasmanian devil, dunnart)) Didelphimorphia(Opossums) Diprotodontia(Possums, tree kangaroo, wallaby, koala) Microbiotheria(Monito del monte) Notoryctemorphia(Marsupial moles) Paucituberculata (Shrew opossums) Peramelemorphia(Bandicoots)


`

Inquiry and Research Project

Case Presentation: Applying Phylogenies Possible Evaluation:

Why do biologists care about phylogenies? One reason is that species’ phylogeny provides enormous amount of information. Example: Corn or maize is the second most important source of food worldwide. From the phylogeny of maize based on DNA, data researchers identified two species of wild grasses that may be the closest relatives of maize. These two closest relatives may prove useful as “reservoirs” of beneficial genes that can be transferred to cultivated maize by plant breeding or genetic engineering. The phylogenetic analysis of maize also led to the identification of the gene responsible for maize’s unique fruiting body, the cob.

Phylogenetic trees have played a key role in a wide range of other applications. Research on other cases and present it to class. I. Investigation whether food sold as “whale meat” in Japan was illegally harvested from whale species protected under international law. II. Application of DNA identification related to bioterrorism. In the fall of 2001, several politicians and journalists were sent envelopes containing anthrax bacteria. Researchers used DNA to identify the strain of bacterium sent inside the envelopes. 116

a. What are the multiple lines of evidence and how are these used to infer evolutionary relatedness? b. Prove that classification is based on evolutionary relatedness.

General Biology 2

180 MINS

Lesson 15: Systematics Based on Evolutionary Relationships: Taxonomy LESSON OUTLINE

Content Standard

The learners demonstrate an understanding of Basic Taxonomic Concepts and Principles, Description, Nomenclature, Identification and Classification. Performance Standard


construct a dichotomous key


20

Motivation

Classification Tasks

30

Instruction

Discussion on Linnaean Classification

60

Practice

Use of dichotomous keys for identification

45

Enrichment

Assignment

15

Evaluation

Group Work

10

Learning Competency

The learners should be able to identify the unique/distinctive characteristics of a specific taxon relative to other taxa STEM_BIO11/12IIIh-j-15 Specific Learning Outcomes


Materials

•

describe the Linnaean system of classification;

Writing materials, sheets of paper, photos of plants (citrus fruits) and animals (turtles)

•

classify organisms into a hierarchy; and

Resources

•

construct and use dichotomous keys for identification.

(1) Pancho JV, William G SM. Vas cular Flora of Mount Mak iling and Vicinity (Luzon: Philippines). Part 2. Laguna, Philippines: National Academy of Science and Technology (NAST) Philipp ines, Department of Science and Technology, Bicutan, Taguig City and Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños College; 2006. 223-241pp. (2) Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology.10 th edition. San Francisco, California, USA: Pearson Education Inc.; 2014. 548-549 pp. (3) Simpson MG. Plant Syst ematics. MA, USA: Else vier Academic Press Publications; 2006. 12-13pp.

Additional Resources at the Back


Teacher Tip: Here are some definitions:


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can describe the Linnaean system of classification. II. I can classify organisms into hierarchy of groups based on similarities and distinct characters. III. I can use and construct dichotomous keys.

Classification– method of grouping organisms; arranging entities into some type of order to provide a system for cataloguing and expressing relationships between these entities

Review

Hierarchy- a system of organizing groups into ranks according to status; putting groups at various levels according to importance or power

2. Say, “The practice of classification is almost everywhere such that, humans tend to classify almost everything. For instance, one can describe the clothes to wear, types of utensils used in the kitchen and even the type of footwear . Classification becomes an essential part of everyday life and the habit can be quite useful. In the past humans have classified living organisms based on their general form and economic use. The type of classification may not be that systematic as

Nomenclature - the formal naming of taxa according to some standardized system. For plants, fungi, and algae, rules for naming are provided by the International Code of Botanical Nomenclature. For animals, rules

compared to the ones we used today. However, it does not deny the fact that they were useful.”

on naming are based on the International Code of Zoological Nomenclature.

Early taxonomists (e.g. Emperor Shen Nung of China around 3000BC) have classified plants based on practical uses—for food, as herbal medicine, for shelter and others.

Identification - is the process of associating an unknown taxon with a known one

At this point, ask learners how they will classify objects or items commonly encountered or used in everyday life such as those found in homes, schools and neighborhood/communities.

Description- is the assignment of features or attributes (characters) to a taxon

The following are sample responses:

Taxonomy- the theory and practice of classifying organisms

I. Kitchen utensils (can be classified based on their use--- spoons, forks, ladles, pots, pans) II. Clothing (skirts, blouses, socks, pants) III. Learners in schools/universities (can be classified based on gender, age group, etc) IV. Books in the Library (can be classified based on Dewey decimal system)

118

Reminder: Taxonomyis a major part of systematics that includes description, identification, nomenclature and classification

3. Ask the learners to define the following biological terms in their own words. I. classification II. description III. hierarchy IV. identification V. nomenclature VI. taxonomy 4. Say, “ About three hundred years ago, a Swedish botanist and doctor named Carl Linnaeus realized: ‘All the real knowledge we have depends on the method by which we distinguish the similar from the dissimilar. The greater the number of natural distinctions we make, the clearer becomes our idea of things…from here Linnaeus set himself the task of devising a method to : “join the similar to the similar, and to separate the dissimilar from the dissimilar in nature” Note that the Linnaeus method was known as Linnaeus’ system of classification or the Linnaean taxonomy. 5. Stress the importance of a classification system, nomenclature and identification 6. Topics to be covered: I. Some Early Taxonomists II. Linnaean System of Classification III. Binomial Nomenclature IV. Classifying organisms based on similar and distinct characters V. The dichotomous key

MOTIVATION (30 MINS) Classification Tasks

1. Tell learners to form a group, with 4 members. 2. Ask them to look inside their bags and gather all possible types of writing and coloring materials they can obtain within their group (e.g. ballpen, sign pen, whiteboard marker, pencil, highlighter, color pens ). Ask learners to classify these materials. 3. Ask learners to write down key features to be used for groupings. Place these features in a table (learners may focus on characters based on absence (-) or presence (+). Sample Table: F e at ur e s

ba l l pe n

short (less than 6 inches)

- -

long (more than 6 inches)

o r d i n ar y pen c i l

+

+

+

+

-

with black ink

+

-

-

without ink

-+

h i g hl i g h t er

whiteboard marker

+ -

-

4. Ask learners to create their own simple hierarchical system of classification by assigning ranks to groups created. They may create a label for the ranks. A flow chart may be constructed.

120

Sample Flow Chart:

5. Ask for a volunteer to present the chart. (This activity will give them the actual feeling of how classification is done.)

INSTRUCTION (60 MINS) Setting the Atmosphere and Discussion

1. After getting a feel of how classification is done, learners begin to appreciate the job of early taxonomists. Discuss a little about the history of classification and the scientists who have contributed to the field of taxonomy. 2. The taxonomic system was devised by Carolus Linnaeus(1707-1778). It is a hierarchical system since organisms are grouped into ever more inclusive categories from species up to kingdom . In 1981, a category higher than a kingdom, called domain, was proposed by Carl Woese. The table below illustrates how four species are classified using the present classification system. (Note that it is standard practice to italicize the genus and species names).

Teacher Tip: Discuss on some scientists’ contribution to the classification system throughout history. For instance, Andrea Cesalpino, John Ray, Augustus Quirinus Rivinus, Joseph Pitton de Tournefort, Robert Whittaker, and Carl Woese. ( Ask learners to make a personal research on their respective contributions.)

D O MA I N

Teacher Tip:

E U K A RYA

KINGDOM

Animalia

Plantae

PHYLUM

Chordata

Arthropoda

Magnoliophyta

CLASS

Mammalia

Insecta

Lilopsida

Diptera

Liliales

ORDER

Primates

FAMILY GENUS

Canivora

Hominidae omoH

specific epithet sapiens SPECIES

Homo sapiens

Canidae Canis

Drosophilidae Drosophila

familiaris Canis familiaris

Liliaceae

melanogaster

cepa

Drosophila melanogaster

human

dog

D O MA I N

E U K A RYA

FE AT U R E S

KINGDOM

Animalia

Organisms that are able to move on their own

fruit fly

Allium capa onion

Note:

PHYLUM

Chordata

Animalswithabackbone

CLASS

Mammalia

Chordateswithfurorhairandmilkglands

ORDER

Primates

Mammalswithgraspingfingers

FAMILY

Hominidae

Primates with relatively flat faces and three-dimensional vision

GENUS

Homo

Hominidswithuprightpositionandlargebrain

specific epithet

sapiens

Membersif thegenus thin skull bones

Homosapiens

COMMON NAME

human

*Classification is based on key characters/ features used in groupings. Take for example the classification of humans. Refer to the table below.

Allium

COMMON NAME

SPECIES

The word ‘species’ is both in singular and plural form; there is no such word as ‘specie’

Homo with a high forehead and notably

122

Most of us are accustomed to the Linnaean system of classification that assigns every organism a kingdom, phylum, class, order, family, genus, and species The Linnean method is artificial since organisms are classified based on morphological similarities and not on evolutionary relationships.

Phylogenetic classification is based on evolutionary history or pattern of d escent.

Teacher Tip: Linnaeus introduced the binomial system of nomenclature for plants, animals, fungi, protozoans and protists. The binomial system consists of the generic name and the specific epithet. Thus, the species name is binomial in nature.

Trivia: What is the longest species name ? Parastratiosphecomyia stratiosphecomyioides This is the scientific name of the soldier fly.

3. The Linnaean taxonomy which is hierarchical in nature is the most employed system nowadays. Note: This system was created long before scientists understood that organisms evolved. 4. Working as teams (4 learners per team) ask learners to come up with their own mnemonic. They may share it with other groups (Which mnemonic works best for you?). 5. Discuss binomial nomenclature. Nomenclature refers to the practice of assigning scientific names. Binomial comes from the words “bi” meaning “two” and “nomen” meaning “name”. A species name consists of two parts: the genus or generic name and the specific epithet. The first letter of the genus is always capitalized (e.g. Canis) while the specific epithet is not capitalized (e.g. familiaris). One can distinguish a species name from the way it is written. Species name can be in bold letters or underlined or italicized.

Sample mnemonics: • •

Kings Play Chess On Fine Glass Sets Kings Play Chess On Finely Green Spaces

• •

Keep Pond Clean Or Froggy Gets Sick Kings Play Chess On Fine Grained Sand

• •

King Philip Came Over For Green Soup Kindly Put Candy Out For Good Learners

Examples: S P E C IE S

Canisfamiliaris Felis catus

ENGLISH MEANING

GEN U S

Canis Felis

adog happy

SPECIFIC EPITHET ENGLISH MEANING

familiaris

familiar

catus

cat

Discuss dichotomous key as a tool in identification. Teacher Tip:

A dichotomous keyis a tool that helps identify unknown organisms to some taxonomic level (e.g., species, genus, family, etc.). The key is constructed in such a way that a series of choices is made that leads the user to the correct identity of a sample organism. "Dichotomous" means, "divided into two parts." Therefore, a dichotomous keyalways offer two choices for each step, each of which describes key characteristics of a particular organism or group of organisms.

Go to 2

1b.Hardtubepackaging

Goto4

2a. Chips have ridged surface

Go to 3

2b. Chips have non-ridged surface

3b.Chipstancolor

Present the plant pictures to learners and give clear instructions on what they need to do.

Note: You may provide photos.

Lays Cheese and Onion

3a. Chips orange color

Tortillos Cheese V-Cut

4a. Chips orange color

Pringles Cheddar Cheese

4b. Chips have other color

Go to 5

Explain the rationale of the activity. The importance of correct identification cannot be underestimated.

Sample Key: Key to common snacks

1a. Plastic bag packaging

Do your personal review on the characteristics of the citrus family before giving this exercise. Be familiar with terms associated with the family.

5a. Chips solid tan with no speckles

Pringles Original

5b. Chips tan with greenish speckles

Lays Stax Sour Cream and Onion 124

6. Now that you have an idea of how a dichotomous is constructed, let us try making one based on real organisms. Let’s try something quite challenging. Practical example/ work with actual groupings

7. Say, ”Many plants in the Philippines are often confused because they share characteristics and look similar….among these are plants belonging to the Citrus family (Family Rutaceae). We are quite familiar with this group but often one identity is interchanged with the other or all examples are treated as the same…” 8. Ask learners to work in groups. Show to class actual fruit samples with few leaves and flowers or if not, colored pictures of these plants belonging to calamansi family (Rutaceae). Generally, family Rutaceae is composed of trees or shrubs that are often spiny and rarely herbal. The leaves can be simple or compound, alternately or oppositely arranged, with few to numerous pellucid glands, and without stipules. In the Philippines, there are 20 genera and 83 species. 9. Using these fruits below from family Rutaceae, tell your learners to observe the features or characteristics of each fruit. Place all these characters in a table. Suggest to them possible characters that they can use like presence/absence of a feature or trait, shape, color etc. Use common names at the end of each choice. I. citron II. key lime III. pomelo IV. makrut lime or Mauritius papeda V. calamondin or calamansi VI. bitter orange VII. mandarin orange VIII.Cochin China Atalantia 10. Ask for group volunteers to show their dichotomous key in class. Comment on how they constructed their key. After the group haspresented their key, showthe correct dichotomous key to your learners. 11. Below is the dichotomous key you will show the learners after they have constructed their own key.

Dichotomous key to the different fruits of family Rutaceae

Teacher Tip

1a. Foliage not constricted; berries less than 2 cm in diameter

Cochin China Atalantia

1b. Foliage constricted; berries exceeding 2 cm in diameter

Citrus

2a. Leaves not constricted; petioles not or narrowly winged; fruits ellipsoid

Citron

2b. Leaves constricted, petioles winged; fruits globose

Go to 3

3a.Flowersinaxillaryracemes 3b.Flowerssolitaryorfascicledinleafaxils

Goto4 Goto5

4a. Basal leaf portion narrowly winged; fruits small

key lime

4b. Basal leaf portion broadly winged; fruits very large

pomelo

5a.Basalleafportionbroadlywinged 5b.Basalleafportionnarrowlywinged 6a.Fruits2-3cmindiameter 6b. Fruits much larger 7a.Fruitstight-skinned 7b. Fruits loose-skinned

makrutlime Goto6 Calamansi Go to 7 bitterorange mandarin orange

12. Ask your learners to compare their key with the one you showed them. After comparing, let them answer the questions below: I. What trait(s) or character(s) did you use to separate the fruits into groups? Give an example to illustrate this. II. Notice differences among fruits. These differences set them distinct from the others. Can you give an example to show this? 13. Stress that the presence of similarities among organisms will place them in a group. Differences among organisms would set them distinct from each other. 126

Glossary of terms 1. axillary–relating to or located in an axil: an axillary bud 2. basal- located at or near the base of a plant stem, or at the base of any other plant part 3. berry –fleshy fruit with many seeds derived from a single flower containing one ovary 4. foliage- collectively, a cluster of leaves 5. fascicled- in bundles or clusters; can be appied to stems, flowers or leaves 6. globose-rounded 7. petiole-the stalk that attaches the leaf blade to the stem; 8. raceme- an inflorescence in which the pedicellate flowers are borne along the main stem, with the oldest flowers at 9.

the base solitary-growing singly

PRACTICE (45 MINS) Learners will still work as a group. 1. Present to each group photos of 4 unknown turtles. Assign a letter or number for each photo. Provide a dichotomous key for each group. 2. Say, “The world has six species of marine turtles with the green sea turtle having two subspecies. The loggerhead, flatback, hawksbill, leatherback and green sea turtle are considered endangered. The olive Ridley is plentiful in some seas. The Philippines is a rich haven for these marine creatures owing that we are part of the Coral Triangle. Now NAME that TURTLE to save it!” 3. Ask learners to use the provided dichotomous key to determine the identity of the unknown turtles. Check if the group got each species correct. Rank each group based on who accomplished the task first. Then, ask each group the difficulties they encountered and how they overcame these difficulties. KEY TO COMMON SPECIES OF TURTLES

1a.Has scutespositions arrangedon in athe distinct patterns forming medial, lateral, and marginal carapace

Go to 2

1b.Has no scutes on the carapace but has longitudinal ridges on the carapace

Leatherback turtle

2a. Medial scutes 5 2b.Medialscutesmorethan5 3a. Lateral scutes 4 3b.Lateralscutesmorethanfour

Go to 3 OliveRidleyturtle Go to 4 Goto5

4a. Medial scutes imbricated and the beak is ‘hooked’ 4b. Medial scutes are not imbricated and the beak is not noticeably hooked

Hawksbill turtle Go to 6

5a. With terminal scute at the centerline along the posterior margin of Kemp’s Ridley turtle the plastron

Teacher Tip Glossary of terms 1. axillary–relating to or located in an axil: an axillary bud 2. basal- located at or near the base of a plant stem, or at the base of any other plant part 3. berry –fleshy fruit with many seeds derived from a single flower containing one ovary 4. foliage- collectively, a cluster of leaves 5. fascicled- in bundles or clusters; can be appied to stems, flowers or leaves 6. globose-rounded 7. petiole-the stalk that attaches the leaf blade to the stem; 8. raceme- an inflorescence in which the pedicellate flowers are borne along the main stem, with the oldest flowers at 9.

the base solitary-growing singly

5b. Without terminal scute at the centerline along the posterior margin of the plastron 6a.Posteriormarginofthecarapacepointed

Loggerhead turtle BlackTurtle

6b. Posterior margin of the carapace rounded

Go to 7

7a. Lateral scutes of the carapace are noticeably larger than the medial scutes

Flatback turtle

7b. Lateral scutes of the carapace are nearly the same size as the medial scutes

Green turtle

Take note of the assigned letter for each picture. A

Black Turtle

E

Kemp’s Ridley Turtle

B

Flatback Turtle

F

Leatherback Turtle

C

Green Turtle

G

Loggerhead Turtle

D

Hawksbill Turtle

H

Olive Ridley Turtle

ENRICHMENT (15 MINS) 1. Ask the learners to submit an assignment on other practical uses of biological classification. EVALUATION (10 MINS) Group Work

2. Divide the class into groups. Learners will still work as a group composed of four (4) members. Ask learners to make their own dichotomous key in order to identify their favorite plants/ vegetables found in a school garden or for instance, in the market. Give them time to think and write down the plants or in their own spare time they can also visit an actual garden. Ask learners to submit their work the following meeting. Ask for difficulties they encountered and strategies they used to make the task easy. 128

Teacher Tip Practice more on using dichotomous keys Practice makes Perfect! Note:

Write down the following in the board. Dermochelys coriacea (Leatherback turtle) Lepidochelys olivacea (Olive Ridley turtle) Eretmochelys imbricata (Hawksbill turtle) Lepidochelys kempii (Kemp’s Ridley turtle) Caretta caretta (Loggerhead turtle) Chelonia mydas agassizii (Black Turtle)subspecies of the Eastern Pacific g reen turtle Chelonia mydas mydas (Green turtle) - subspecies of the Eastern Pacific green turtle Natator depressus (Flatback turtle) Glossary of terms 1. Carapace-a bony or chitinous covering on the dorsal part of the turtle 2. Imbricated- overlapping or layered as scales and shingles 3. Lateral-relating to the side or sides 4. Medial- relating to or situated toward the middle 5. Plastron-the ventral part of the shell of the turtle 6. Posterior-located behind a part or toward the rear of a structure; on or near the hind end 7. Scutes-a chitinous bony external plate, as on the shell of a turtle 8. Terminal-situated at, pertaining to or forming the end; towards the end

General Biology 2

180 MINS

Lesson 16: Systematics Based on Evolutionary Relationships: Cladistics and Phylogeny LESSON OUTLINE


30

Content Standard

Motivation

The learners demonstrate an understanding of Basic Taxonomic Concepts and Principles, Description, Nomenclature, Identification and Classification

Café Conversation

20

Instruction

Works in Pairs

50


Practice

Constructing Cladograms

40


Enrichment

Test your Skill After Class: Peer Evaluation

30 10

•

make simple cladograms

Learning Competency

The learners should be able to describe species diversity and cladistics, including types of evidence and procedures that can be used to establish evolutionary relationships STEM_BIO11/12IIIh-j-16 Specific Learning Outcomes


demonstrate how shared derived characters can be used to reveal degrees of relationship; and

•

build cladograms to infer evolutionary relatedness

Evaluation Materials

Writing materials, sheets of paper, photos of animals ( may be provided as worksheet)

Resources (1) Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. Campbell Biology.10 th edition. San Francisco, California, USA: Pearson Education Inc.; 2014. 551-558 pp. (2) Taxonomic Classification and Phylogenetics Trees.trees.http:// www.mhhe.com/biosci/pae/zoology/cladogram/index.mhtml. 17 August 2015 (3) Cladogram and Phylogenetic Trees:Evoution Classifications.http:// study.com/academy/lesson/cladograms-and-phylogenic-treesevolution-classifications.html. 17 August 2015. (4) Constructing a Phylogenetic tree. http://evolution.berkeley.edu/ evolibrary/article/0_0_0/phylogenetics_11. 17 August 2015.


Teacher Tip: Here are some definition of terms:


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can demonstrate how shared derived characters can be used to reveal degrees of relationship. II. I can build cladograms to infer evolutionary relatedness.

Phylogeny- the evolutionary relationships among organisms Cladogram- a phylogenetic tree that shows relationship of taxa based on shared derived characters

Review

1. Say, “Look around you, and see the enormous diversity the natural world has to offer. However, amidst such diversity is also an amount of similarity which you can observe. This gives us the idea that somehow, organisms are indeed related. Life is somehow interconnected to each other.” Systematics is the study of the diversity of organisms in the evolutionary context. It intends to use phylogeny in classifying organisms. Phylogeny is the study of the evolutionary history and relationships among organisms. Evidences from awide variety of sources including paleontology, embryology, morphology, anatomy and molecular biology can be used to establish phylogeny. Over the last few centuries systematists have developed different approaches to show relationships among organisms. The most commonly used is cladistics. 2. Discuss briefly: Cladisticsstudies relationships between taxa using shared derived characters. The basic assumption behind cladistics is that members of a group share a common recent ancestor and are thus more "closely related" to one another than they are to other groups of organisms. Related groups of organisms are recognized because they share a set of derived characters. These derived characters were inherited from a recent ancestor. 3. Ask your learner to define the following terms in their own words:

Character- any trait of an organism that can be described or measured Character state - describes the character. A particular character can have several character states. Example: Corolla is a character. Character states can be: shape of the corolla, color of corolla, number of petals comprising the corolla. Homologous characters - characters having similar structures because these were derived from a common ancestor -characters that have Analogous characters separate evolutionary srcins, but are superficially similar because they perform the same function. Analogous characters are the result of convergent evolution.

I. analogous character II. character

Example: Bird and bat wings are analogous since both are used for flying.

III. character state IV. clade

Clade- a group of taxa consisting of an ancestor and all of its descendant taxa

V. cladogram VI. homologous character VII. phylogeny 130

4. Stress that similarities among existing organisms (including morphological, developmental, and molecular similarities) reflect common ancestry and provide evidence for evolution. I.

Outline:

A. shared derived characters can be used to reveal degrees of relationship B. constructing and interpreting a phylogenetic tree

MOTIVATION (20 MINS) Café Conversation

1. Ask learners: “Do you remember the last time you had a family reunion? A summer vacation or a family barbecue and the latest family picture taken together? Can you describe your family members? What makes you similar to them and what makes you unique?” 2. Ask learners to list characters or features that served as evidences (e.g. morphological, genetic, etc.) that indeed they belong to the same family. Ask learners to note as many asthey can think of. Sample responses:

• • • • • •

Color of the eyes (e.g. brown, black) Texture and color of the hair (e.g. curly black hair) Color of the skin (e.g. fair complexion) Blood type (e.g. A, AB, O, B) Height Shape of the nose

. Family trees show how people are 3. Explain, “Basically, a family picture represents a family tree related to each other. Similarly, scientists use phylogenetic trees like cladogramsto study the relationships among organisms. Sometimes, family trees are used to show relationships between individuals. Those who are closely related are located closer together than those who are only distantly related. For instance, in a family tree, we can see that the siblings are close together, indicating a close genetic relationship. But the siblings are far from their great aunt, indicating a more distant genetic relationship. Family trees can also be used to see ancestral connections. That is, we can see that all the people in the last generation have the same great-great-grandparents in common.

Teacher Tip: Suggestion: Include a website or video that learners can view to understand how to construct a cladogram. Explain the rationale of the activity.

This same idea of relationships can be used in science. Biologists use phylogenetic trees to illustrate evolutionary relationships among organisms. 4. Stress that for the succeeding activities, focus will be on constructing and interpreting a simple phylogenetic tree.

INSTRUCTION (50 MINS) Discussion:

A. shared derived characters can be used to reveal degrees of relationship B. constructing and interpreting a phylogenetic tree Work in Pairs and Build that Tree

1. Ask learners to choose a partner and work in pairs. 2. For this activity, present to learners a diverse group of vertebrates and ask them to make a phylogenetic tree showing their evolutionary relationships. This tree should be primarily based on physical characteristics , such as: I. Presence or absence of a backbone II. Ability to breathe in air or water III. Cold or warm blooded IV. Carnivore, herbivore, or omnivore

Teacher Tip: Constructing a phylogenetic tree is one way to visualize evolutionary relatedness. In this activity, guide learners on how to construct their own tree from a set of animals provided, using only observable physical features. This activity gives learners an opportunity to classify organisms on their own, and they can visualize the types of evidence used to show evolutionary relationships. Due to the open-ended nature of this activity, learners will come up with many different combinations and layouts. However, the end result should be an evolutionary tree that shows the basic relationship among animals. Arthropods such as the spider and moth should be far apart from an aquatic mammal such as the walrus. This is also a good opportunity to gauge how well learners understand the basis of different classifications, such as reptile, amphibian, and mammal. Phylogenetic systematics emphasize descent and common ancestry in order to determine the evolutionary history of groups of organisms as a determining factor in classification

V. Presence or absence of hair/fur VI. Any other external structures such as horns

132

Note: The following outline drawings of animals are provided for the activity. These can be printed and cut out for learners to work with.

3. Ask learners to work in pairs and individually cut out each animal, including the name. as the first 4. Ask them to lay all the animals on their desks and separate them into two groups using the presence or absence of a backbone character. 5. On a separate sheet of paper, start constructing the phylogenetic tree like the one shown below. 6. Ask learners to continue separating the animals into smaller groups using the characters in number two. 7. When an animal reaches the tip of the branch, glue it. Repeat for all other animals in the collection. 8. Ask volunteers to present their phylogenetic tree in class.

PRACTICE (40 MINS) 1. Learners will still work in pairs. 2. Ask each pair to construct a cladogram based on the data provided. Homalozoa (Outgroup) Water vascular system Number ambulacral of grooves

Closed ambulacral grooves Aboral surface reduced Ambulacral grooves extended from oral to aboral Endoskeleton

A s t e r o id

YES

3

On podia

No

Yes

No No

Highlyflexible

Yes

Notflexible

Flexible

Highlyflexible

Constructing a Cladogram 1. Ask learners to use the data below to arrange the groups of organisms based on their shared derived traits. This time you will be using distantly related organisms or a taxon termed an outgroup. 2. For each group, the traits or characters are already listed. For each character, determine which state is ancestral or primitive and which is derived. This is usually done by comparing with the outgroup. Traits found in the outgroup are likely to be ancestral or primitive. Similarly, traits not found in the outgroup are considered as derived. In cladistics, it is the derived trait shared among taxa that should be placed in the cladogram. 3. Group taxa according to their shared derived character(s). 4. Once you have evaluated all the characters, you may start constructing your cladogram. Where do you place the outgroup?... (Correct, an outgroup is always placed at the base of the cladogram.) 5. Choose a learner to present the cladogram. After this, show them the correct cladogram below. 134

Yes

Yes No

Oral On podia

Yes

No No

Internal On podia

No

No

5

None Absent

Yes

Yes

YES

5

Aboral On podia

O p t h i u r io d

YES

5

Aboral

Non on podia

H olot h ur oid

YES

5

Aboral

C r in o id

YES

5

Madreporita Suckers

E c h in o id

YES

Yes Yes

Highlyflexible

No

Highlyflexible

ENRICHMENT (30 MINUTES) 1. Now you're getting the hang of this! Once again, use the data below to arrange organisms based on their shared derived characters. This time work again with your partner and test your skill in building a cladogram.

Of course, this was just an example of the tree-building process. Phylogenetic trees are generally based on many more characters and often involve more lineages. For example, biologists reconstructing relationships between 499 lineages of seed plants began with more than 1,400 molecular characters.

EVALUATION (10 MINUTES) 1. Go online. Choose a group of organisms you are interested to work with (e.g. invertebrates); 2. Download pictures of different species. 3. Print the pictures. In tabular form, list all the characters. Evaluate the characters (whether primitive or derived). 4. Remember that in building your cladogram, use only shared derived characters. 5. Construct your own cladogram. 6. Share this with your seat mate and discuss your cladogram. 7. The outputs may be submitted as soon as it is discussed. 8. Learners can compare their work and provide each other with feedback (peer assessment). Remind learners to make specific suggestions and recommendations and what could be improved. Ask for difficulties they encountered and strategies used to make the task easy.

General Biology 2

60 MINS

17.1: Introduction to Reproduction LESSON OUTLINE

Content Standard

The learners demonstrate an understanding of Asexual and Sexual Modes of Reproduction Performance Standard


Pictures of Different Types of Reproduction

10

Instruction

Discussion on Two Forms of Reproduction

45

Enrichment

Reporting on Specific Examples of Asexual and Sexual Reproduction


discuss the advantages and disadvantages of sexual and asexual reproduction

Learning Competency

5

Motivation

The learners should be able to compare various modes of asexual and sexual reproduction (STEM_BIO11/12-IVa-h-1)

Materials


Pictures of different examples of reproduction, materials for reporting (i.e. LCD projector and computer or illustrations on Manila paper)


differentiate asexual from sexual reproduction; and

•

describe different modes of sexual and asexual reproduction

Resources

(1) Hickman, C.P. Jr., Roberts, L.S., Larson, A. and l’Anson, H. 2004. Integrated Principles of Zoology, (12 th ed). McGrawHill Education. (2) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. (2012). Campbell Biology, (9th ed). The Benjamin Cummings Publishing Co., Inc.

136

INTRODUCTION (5 MINS) Communicate Learning Objectives

Introduce the following learning objectives: 1. I can differentiate asexual and sexual modes of reproduction. 2. I can describe different modes of sexual and asexual reproduction.

Teacher Tip: Tell the learners that the list of defined terms need not be memorized. They are to be mentioned during the course of the discussions.

Relevant vocabulary

- Mode of reproduction that does not involve the use of gametes or sex cells 1. Asexual reproduction - Mode of reproduction that involves the use of gametes or sex cells 2. Sexual reproduction 3. Fission- Type of asexual reproduction involving the division of body into two or more equal parts 4. Fragmentation- Type of asexual reproduction where the body breaks into two or more parts, with each fragment capable of becoming a complete individual; in animals, fragmentation is usually followed by regeneration where the missing parts are produced. For example, a lost arm of the starfish may be regenerated by mitotic cell divisions. Budding 5. its Type of asexual where a new arisesitself. as an outgrowth (bud) from parent,- develops organs reproduction like those of the parent, andindividual then detaches

6. Sporulation- Type of asexual reproduction where a new individual forms from an aggregation of cells surrounded by a resistant capsule or spore, which later on germinates

Figure 1.Paramecium undergoing

asexual reproduction through fission

7. Isogamy- Fusion of similar gametes which are usually motile 8. Heterogamy- Fusion of dissimilar gametes. In oogamy, a large immotile gamete, the egg is fertilized by a small motile gamete, the sperm. - Type of sexual reproduction involving the union of gametes from two 9. Bisexual reproduction genetically different parents 10. Hermaphrodite- An individual with both male and female reproductive tissues. In animals “self fertilization” is not common. In worms, a hermaphrodite needs a male to donate sperms in order to fertilize the oocytes in its body.

MOTIVATION (10 MINS) 1. Show pictures of the following: A. Paramecium undergoing fission (see figure 1) B. Hydra undergoing budding (see figure 2)

Figure 2.Asexual reproduction

through budding in Hydra

C. A filamentous alga, i.e. Spirogyra, or a starfish arm undergoing fragmentation (see figure 3) D. A fungus, i.e. Rhizopus, producing conidia/spores (see figure 4) E. Two frogs in amplexus (see figure 5) Provide this narrative to the class:

The following pictures depict reproduction across different organisms. As animals, we are only familiar with one form of reproduction, particularly the form depicted by the frogs in amplexus. However, there are other forms of reproduction that exist in nature. Can you spot differences among the depicted forms of reproduction?

Figure 3.Asexual reproduction

through fragmentation

INSTRUCTION (45 MINS) Discussion

1. Differentiate asexual and sexual reproduction. 2. Types of asexual reproduction and give examples I. Fission- Paramecium as example II. Budding- Hydra as example III. Fragmentation- filamentous alga, i.e. Spirogyra or Oedogonium, and a detached starfish arm growing lost parts as example Figure 4.Fungi undergoing asexual

IV. Sporulation- fungus, i.e. Rhizopus, as example 3. Describe types of union of gametes and give examples

reproduction through sporulation

I. Isogamy- Chlamydomonas producing gametes orSpirogyra undergoing conjugation as example II. Heterogamy- animal sperm and egg as examples 4. Special terms for sexual reproduction I. Bisexual reproduction. Examples are in humans, and papaya among others. II. Hermaphrodites- barnacles; worms Figure 5.Frogs mating (in

amplexus) 138

5. Summarize differences between asexual and sexual reproduction ASEXUAL REPRODUCTION

Numberofparentsinvolved Gametes

one

Teacher Tips: SEXUAL REPRODUCTION

two Noneedforgameteunion

Genetic composition of offspring Genetically identical to parent (Clone)

Present;spermhastofertilize the egg Generally are hybrids of parents

ENRICHMENT

1. Ask the learners to research on the advantages and disadvantages of asexual and sexual reproduction. They will then submit their assignment during the next meeting. 2. If microscopes are available, slides of the organisms mentioned above may be observed. The teacher may ask the learners to draw the specimens under low power and high power objectives of the microscope.

Emphasize that in asexual reproduction, an offspring is genetically identical to the parent, which means the offspring is a CLONE of the parent. Sexual reproduction, on the other hand, generally produces variation in the offspring because this results in the recombination of genomes from the parents’ gametes. Note that sporulation is very rare in animals and are only exhibited in some organism like sponges. Note that isogamy may involve either flagellated gametes (as in the case of Chlamydomonas) or non-flagellated cells or structures (as in the case of Spirogyra)

General Biology 2

235 MINS

Lesson 17.2: Compare and Contrast Process in Plants and Animals: Reproduction and Development LESSON OUTLINE


30

The learners demonstrate an understanding of Animal Reproductive Organs and Their Functions; Processes in development

Motivation

Start of Drosophila Life Cycle of Experiment

30


Instruction

Discussion of Different Stages of Animal Development

Content Standard


145

illustrate the life cycle of the common fruit fly, Drosophila/ Debate on when Enrichment Illustration of the Life Cycle of human life begins Drosophila

Learning Competency

The learners should be able to describe processes in the life cycle of animals and explain the process of human development STEM_BIO11/12-IVa-h-1 Specific Learning Outcomes

30

Materials Wide-mouthed clean and empty bottles, potatoes or sweet potatoes or bananas, fruit flies, shallow basin, pen and p aper, pictures of humans at different stages of development

Resources


describe the different stages of animal development;

•

differentiate the developmental process in monozygotic and dizygotic twins;

•

describe human reproductive organ systems;

•

illustrate the human female menstrual cycle;

•

explain processes in human development; and

•

differentiate various forms of contraception in humans

(1) Hickman, C.P. Jr., Roberts, L.S., Larson, A. and l’Anson, H. 2004. Integrated Principles of Zoology, (12 th ed). McGrawHill Education. (2) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. 2012. Campbell Biology, (9th ed). The Benjamin Cummings Publishing Co., Inc. (3) Sheridan, M. 1999. Instructor’s guide for Biology, th5 ed. By Campbell, Reece, Mitchell. Addison Wesley Longman, Inc.

140


Teacher Tip:


Note that even unicellular forms like bacteria and fungi also undergo development

1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can describe the different stages in animal development. II. I can differentiate the developmental process in monozygotic and dizygotic twins. III. I can describe the human reproductive organ systems. IV. I can illustrate the human female menstrual cycle. V. I can explain processes in human development. VI. I can differentiate various forms of human contraception. Relevant Vocabulary

- involves formation of sex cells, zygote formation, subsequent stages in one’s life 1. Development span. Development is terminated by death. 2. Haploid(n) condition- When a cell has only half the chromosome number or only one set of chromosomes 3. Diploid(2n) condition- When a cell has the full chromosome number or two sets of chromosomes - A cell that is capable of differentiating to become any kind of cell 4. Totipotent cell - Stage of development that yields haploid gametes 5. Gametogenesis - Stage of development that results in a unicellular diploid zygote 6. Fertilization 7. Cleavage- Stage of development involving a series of mitotic divisions to produce a multicellular blastula from a unicellular zygote - Stage of development involving morphogenetic movements of the cells to produce 8. Gastrulation a gastrula with distinct germ cell layers; in vertebrates, this will result in three layers: the outermost ectoderm; the inner endoderm, and the middle layer, the mesoderm - Stage of development where the different germ layers differentiate into specific 9. Organogenesis organ systems 10. Growth- Stage of development characterized by an increase in size of an individual - Also known as identical twins; result from the union of a sperm and egg to 11. Monozygotic twins form a single zygote that splits up during the first cleavage stage.

Figure 1.Different stages of human

development

- Also known as fraternal twins; results from the development of two or more 12. Dizygotic twins separate fertilization events where the resulting zygotes develop almost simultaneously 13. Testis- Where sperms are produced 14. Epididymis- Where sperms are temporarily stored - Supports the testis and epididymis 15. Scrotal sac/scrotum 16. Vas deferens- Where the sperm passes through from the testis before it joins the urethra 17. Urethra- Connected to the urethra and the urinary bladder; serves as passageway of both sperm and urine and terminates in the external urinary meatus of the penis 18. Seminal vesicle- Secretes fluid that forms part of the semen; secretion gives the semen its alkaline characteristic to counteract the acidity of the vaginal tract and therefore protect the sperm; the fluid also contains sugars like fructose - Secretes fluid that also provides alkalinity to the semen; it also contains 19. Prostate gland proteolytic enzymes, citric acid, phosphatases, and lipids - Paired glands that produce clear, viscous secretion known aspre-ejaculate 20. Bulbourethral glands that helps to lubricate the urethra for sperm to pass through, neutralizing traces of acidic urine in the urethra, and helps flush out any residual urine or foreign matter 21. Clitoris- The homologue (equivalent) of the penis in females 22. Vagina- Main entrance to the female reproductive tract; receives the penis during sexual intercourse 23. Cervix- Where the vagina ends; projection of the uterus into the vagina; leads to the uterus 24. Uterus- Also known as the womb; where the embryo develops; with thick muscular walls, blood vessels; and the endometrial lining - Innermost lining of the uterus where the embryo implants and 25. Endometrial lining/endometrium develop - Also known as oviducts; paired tubes that are connected to the uterus and 26. Fallopian tubes terminate near the ovaries; this is where fertilization takes place 27. Ovaries- Female gonads that release the oocytes during ovulation, which are then caught by the fimbrae of the fallopian tubes in order for the oocytes to pass on to the fallopian tubes 28. Morula- A human blastula made up of a solid ball of cells - A human blastula composed of the inner cell mass, which becomes the embryo, and 29. Blastocyst the trophoectoderm, which becomes the placenta 142

Figure 2.Human male reproductive system. (See vocabulary for definition of terms.) (WikipediaBlausen.com staff. "Blausen gallery 2014". Wikiversity )

- Process where the blastocyst implants itself in the endometrium; this signals the start 30. Implantation of pregnancy 31. Gestation- Carrying of the embryo inside the female reproductive tract, specifically the uterus; can last up to 9 months in humans - Corresponds to the first two months of gestation 32. Human embryo 33. Human fetus- Corresponds to the months 3-9 of human gestation - Part of the menstrual cycle of the ovary in humans where the follicles begin to 34. Follicular phase mature; it is marked by secretions of the follicle-stimulating hormone (FSH) and the leutinizing hormone (LH) by the anterior pituitary gland and the estrogen by the ovaries; both FSH and LH stimulate the maturation of the oocytes while estrogen stimulates uterine lining growth in preparation for implantation of the embryo - Part of the menstrual cycle of the ovary after the oocytes are released from the 35. Luteal phase follicles; the remains of the follicle become the corpus luteum, which then secretes progesterone, which stimulates the uterus to undergo final maturational changes that prepare it for gestation to house and nourish an embryo - Part of the menstrual cycle of the uterus; also known as the “period”; 36. Menstrual phase corresponds to the early part of the follicular phase of the ovaries (days 1-5) when endometrium degenerates and sloughs off, producing the menstrual discharge - Part of the menstrual cycle of the uterus; corresponds to the latter part of the 37. Proliferative phase follicular phase of the ovaries (days 8-14) when the endometrium heals and begins to thicken as a consequence of estrogen secretion - Part of the menstrual cycle of the uterus; corresponds to the luteal phase of the 38. Secretory phase ovaries; the endometrium undergoes final changes before it receives the embryo during implantation - Process that blocks any one of the following stages of reproduction in humans: (1) 39. Contraception release and transport of gametes; (2) fertilization; (3) implantation; (4) actual completion of development of the embryo/fetus 40. Ovulation-suppressing methods- Type of contraception that prevents the oocyte to mature - Type of contraception taken in by women to prevent them from ovulating 41. Oral contraceptives - Type of contraception that prevents fertilization 42. Barrier methods

Figure 3.Human female reproductive system. (See vocabulary for definition of terms.) (Wikipedia)

43. Condom- Type of barrier method that is inserted on the male penis to prevent release of sperm into the female reproductive tract 44. Diaphragm- Type of barrier method that blocks the cervix, thereby preventing the passage of the sperm into the uterus - Type of barrier method that covers the cervix and blocks passage of the sperm into 45. Cervical cap the uterus - Type of barrier method that kills the sperm on contact; they are placed 46. Spermicidal jelly or foam inside the vaginal canal - A special type of contraception preventing fertilization that involves surgery 47. Surgical methods - Type of surgical method for men; entails cutting the vas deferens 48. Vasectomy - Type of surgical method for women; entails cutting the fallopian tubes 49. Tubal ligation - Type of contraception that prevents the blastocyst from 50. Implantation-suppressing methods being implanted in the endometrium - Type of implantation-suppressing method that physically blocks the 51. Intra-uterine devise (IUD) blastocyst form implanting into the endometrium - Type of implantation-suppressing method that blocks the action of hormones 52. Morning-after pill that prepare the uterus to receive the embryo 53. Abortion- Type of contraception that involves the deliberate removal of the embryo/fetus before it completes gestation - Type of contraception that requires the man to remove the penis before 54. Coitus interruptus ejaculation - Type of contraception where the man and the woman do not engage in sexual 55. Abstinence intercourse

144

Figure 4.Different types of contraceptives

MOTIVATION (30 MINS) 1. Show a picture of the fruit fly,Drosophila. (see Figure 5) 2. Then, provide this narrative to the class: This is the fruit fly, Drosophila. Like all organisms, it goes through development as manifested by its life cycle. Let us characterize its development by making observations of its life cycle. 3. Divide the class into groups of four, after which he/she explains how to conduct the Drosophila life cycle experiment (see details of the experiment at the end of this document). The learners will carry out the experiment for the next two weeks.

INSTRUCTION (145 MINS) 1. Define development and life cycle I. Stages of Animal Development

A. Gametogenesis i. Recall meiosis from Grade 11 ii.Differentiate diploid and haploid cells within the context of meiosis B. Fertilization C. Cleavage i. Define totipotent cells within the context of cleavage in vertebrate animals D. Gastrulation- formation of three germ layers: ectoderm, mesoderm and endoderm. Each will give rise to specific tissues and organs. E. Organogenesis i. Show fates of each germ layer in a typical vertebrate animal (see table 1 at the end of this document) F. Differentiation and Growth 2. Differentiate monozygotic and dizygotic twins.

Figure 5.Drosophila melanogaster (Wikipedia) Teacher Tips: Explain that development starts with formation of sex cells and ends only by death. Until the old age of a person, for example, some cells still develop or divide. The teacher should note that during gastrulation, the fates of the cells are beginning to be determined. The cells started out as totipotent in cleavage, but as the cells are moved around through morphogenetic movements, they become more specialized in terms of their fates as they get assigned to specific germ layers. The teacher should note that identical twins result from an accident during cleavage when totipotent cells, whose fates have not yet been determined, are separated and continue with their development independently of each group of cells. Identical twins should have i dentical gender, whereas fraternal twins may have different biological sex.

Teacher Tips:

3. Differentiate human male and female reproductive organs

I. Human male reproductive system A. Show illustration of human male reproductive system and give the function of each part II. Human female reproductive system A. Show illustration of human female reproductive system

4.Describe human development I. Fertilization- Occurs in the fallopian tube; results in a unicellular zygote II. Cleavage- Also takes place in the fallopian tube after fertilization III. Describe Morulaand Blastocyst - Attachment of blastocyst to endometrium of uterus; start of pregnancy IV. Implantation V. Gestation- Differentiate embryonic development from fetal development in terms of period covered during gestation

Emphasize that pregnancy officially commences only when the embryo (blastocyst) has successfully implanted into the endometrium. Discuss the topic of contraception with as much objectivity as possible. If the teacher cannot teach the topic on the ground of his/ her religious convictions, then the teacher should refer the task to another teacher who may be willing to teach this sensitive topic. Emphasize that abortion should never be done. Emphasize that elective abortion (when the life of the mother is not threatened by the pregnancy) is illegal in the Philippines. Emphasize that abstinence is the only form of contraception that is guaranteed 100% effective

5. Describe the events in the Menstrual Cycle

: Follicular phase; Ovulation; Luteal Phase I.Ovarian cycle : Menstrual phase; Proliferative phase; Secretory phase II.Uterine cycle 6. Contraception and its Types

I. Ovulation-suppressing methods- Oral contraceptives - Physical (Condom, Diaphragm, Cervical cap) II. Barrier methods III. Chemical- Spermicidal jelly and foam - Vasectomy and Tubal ligation IV. Surgical methods - IUD and Morning-after pill V. Implantation-suppressing methods VI. Others: Abstinence

146

It is the your discretion whether you will show pictures of contraceptives or not.

ENRICHMENT (30 MINS) 1. The learners carry out the Drosophila life cycle experiment, then submit the life cycle illustration to the teacher after two weeks. 2. Show the following pictures (see figure 8 as sample): I. Sperm and egg II. Blastula (morula or blastocyst) III. An embryo (less than two month) implanted in the uterus IV. A fetus inside the uterus (3-9 months) V. A baby VI. An adult human 3. Provide this narrative to the class: The following pictures show humans at various stage of development. Question: when do you think human life begins? How about an embryo? How about a baby? Would you consider a single cell like a sperm or egg human? If so, should a single cell from our body, like a red blood cell or liver cell, be likewise considered human? 4. Group the learners into four and encourages them to discuss among themselves how their answer is correlated to which type of contraception they may use, if any. Materials

•

Wide-mouthed glass bottles

•

Potatoes or sweet potatoes or bananas

•

Paper

•

Rubber bands

•

Shallow basin

Procedure

I. Collecting wild fruit flies A. Prepare a clean glass bottle with a wide mouth (i.e. Gatorade). B. Place banana peels inside the bottle.

C. Leave the bottle open and set aside for a day in a cool, dry place. D. When there are enough flies, cover the bottle with a piece of paper secured by a rubber band.

Table 1. Fates of the cells of each germ layer in vertebrate animals G E R M L AY E R

II. Culturing fruit flies

Nervouss ystem (brain and spinal cord), epidermis, sense organs

Mesoderm

muscles,bones, cartilage, circulatory, excretory, and reproductive

A.Boil sweet potatoes or potatoes. Remove the skin, and mash. (Alternatively, bananas may be used, but do not boil them.) This will serve as the medium/ food for the fruit flies. B. Add a small amount of the food medium into a bottle. (The bottle should only be approximately 1/10 full.) Use the same type of bottle as that used to catch fruit flies so that the mouth openings will be the same. Be sure to flatten the medium at the bottom of the bottle so that the medium will not fall off if the bottle is placed upside down. C. Transfer the fruit flies from the catch bottle to the culture bottle. Do this by placing the culture bottle on top of the catch bottle with their mouths touching each other. Remove the paper cover of the catch bottle and let the flies move to the medium bottle. When there are at least 10 flies in the culture bottle, immediately cover the bottle with paper secured with rubber bands. D. Store the culture bottles in a cool, dry place in the class room or laboratory. Place the bottles on a shallow basin with water to prevent ants from going into the medium. III. Observing the life cycle of the fruit flies

A. Take note of the date when the flies were cultured. This is indicative of the approximate time the eggs will be laid. B. Record the date when the larvae first emerged. These will appear as small maggots crawling on the medium or at the inner side of the bottle. Draw or take pictures of the larvae. C. Record the date when the pupae first emerged. These will appear as small cocoons sticking at the inner side of the bottle. Draw or take pictures of the pupae. D. Record the date when the adult flies first emerged. Draw or take pictures of the adult flies. E. Draw the life cycle of the fruit fly. Include the approximate number of days it takes for each stage to emerge based on observations.

148

FAT E S

Ectoderm

Endoderm

organs digestive and respiratory organs, endocrine glands, germ cells and gametes

General Biology 2

120 MINS

Lesson 17.3: Compare and Contrast Process in Plants and Animals: Reproduction and Development Content Standard

LESSON OUTLINE

The learners demonstrate an understanding of Plant Reproductive Organs and their Functions.



Instruction

Discussion of General Life Cycle of

Enrichment

Plants, and the Parts of the Flower Classification of Flowers


identify the parts of the flower, classify flowers, and explain plant development

Learning Competency

The learners should be able to compare and contrast different types of plant life cycles, and explain processes in flowering plant reproduction and development (STEM_BIO11/12-IVa-h-1) Specific Learning Outcomes


enumerate the different types of reproductive cycles;

•

illustrate the life cycles of moss, fern, and flowering plant;

•

describe double fertilization in flowering plants; and

•

explain processes in plant development.

5 115

Materials

Gumamela flower, other flowers, scalpel blade, pencil and paper Resources

(1) Hickman, C.P. Jr., Roberts, L.S., Larson, A. and l’Anson, H. 2004. Integrated Principles of Zoology, (12 th ed). McGrawHill Education. (2) Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and Jackson, R.B. 2012. Campbell Biology, (9th ed). The Benjamin Cummings Publishing Co., Inc. (3) Sheridan, M. 1999. Instructor’s guide for Biology, th5 ed. By Campbell, Reece, Mitchell. Addison Wesley Longman, Inc.


Teacher Tip:


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can enumerate the different types of reproductive cycles. II. I can illustrate the life cycles of algae, moss, fern, and flowering plant. III. I can describe double fertilization in flowering plants. IV. I can explain processes in plant development

The glossary of terms need not be memorized. They are to be mentioned as the teacher explains the different aspects of reproduction which are interconnected with processes of development. For instance, reproduction requires that sex cells be developed. Ask the learner to recall the differences between mitosis and meiosis from Biology 1.

Relevant Vocabulary

1. Gametophyte- Stage of the life cycle of a plant that is haploid; stage that produces gametes via mitosis; these gametes fuse to form a zygote that develops into a sporophyte 2. Sporophyte- Stage of the life cycle of a plant that is diploid; it is the most recognizable structure sporangiain most flowering plants; it produces haploid spores by meiosis in structures called - Life cycle where the haploid stage (gametophyte) is multicellular and the 3. Haplontic life cycle only diploid stage is the fertilized egg cell - Life cycle that includes multicellular diploid (sporophyte) and haploid 4. Haplodiplontic life cycle (gametophyte) generations - Life cycle where the diploid stage (sporophyte)is multicellular and the 5. Diplontic life cycle haploid stage (gametophyte) is represented by the single-celled gametes 6. Angiosperms- Also known as flowering plants; group of plants that produce reproductive structures called flowers in their sporophyte stages 7. Flower- Reproductive structure in flowering plants; made up of four major whorls 8. Sepals- The outermost whorls of a flower; collectively called the calyx 9. Petals- Whorl inner to the sepals; may be brightly colored in some; collectively called the corolla 10. Stamen- Whorl inner to the petals; the male reproductive structure of the flower; bears the male sporangia (also known as microsporangia) 11. Anther- Part of the stamen that contains the microsporangia that develops into pollen grains 150

PARTS OF A GENERALIZED FLOWER.

12. Filament- Part of the stamen that serves as the stalk of the anther - Innermost whorl of the flower; the female reproductive structure of the flower; 13. Pistil or carpels bears the female sporangia (also known as the megasporangia) 14. Stigma- Part of the pistil where the pollen grain derived from the microsporangium attaches during pollination 15. Style- Part of the pistil that serves as the stalk of the stigma; leads to the ovary 16. Ovary- Found at the base of the pistil; contains one or more ovules; eventually becomes the fruit 17. Ovule- Contains the female sporangia or megasporangia; eventually becomes the seed 18. Complete flower- A flower with sepals, petals, stamens and carpels 19. Incomplete flower- A flower that lacks one or more of the floral whorls 20. Perfect flower- A flower that has both stamens and carpels; a bisexual structure 21. Imperfect flower- A flower that has only either the stamens (staminate flower) or the carpels (carpellate flower); also known as a unisexual flower - A plant having perfect flowers or both staminate and carpellate flowers on 22. Monoecious plant the same individual - A plant having only either the staminate or carpellate flower 23. Dioecious plant 24. Pollination- The placement of the pollen grain from the anther to the stigma of a carpel 25. Pollen grain- The immature male gametophyte that develops within the anthers of stamens; derived from the microsporocytes inside the microsporangia of anthers. Inside the mature pollen grain, there is a tube cell and a generative cell. The tube cell develops into the pollen tube as it enters the style and eventually enters the micropyle of the ovule. The generative cell divides into two sperm nuclei and traverses the pollen tube 26. Embryo sac- The female gametophyte found inside the ovule; derived from the megasporocyte inside the megasporangia; a mature embryo sac contains 8 nuclei. Eventually, these nuclei become enveloped by membranes to become real cells. These are the one egg cell; two synergids that flank the egg; two polar cells that are often fused; and three antipodals opposite the synergids and egg. 27. Micropyle- The opening through the integuments of the ovule that surrounds the embryo sac; this is where the pollen tube enters in order to reach the embryo sac

PARTS OF A GUMAMELA

Hibiscus rosa-sinensis

28. Endosperm- Part of the mature seed that is derived from the fusion of the sperm nucleus and the two polar nuclei of the embryo sac. This becomes a nutritive tissue with triploid cells that serves to store food for the developing embryo 29. Zygote- Part of the mature seed that forms as a result of the fusion of the egg and one of the sperm nuclei 30. Cotyledon- Embryonic leaf that forms inside the seed 31. Monocot- A plant with only one cotyledon inside its seed (monocotyledonous) 32. Dicot- A plant with two cotyledons inside its seed (dicotyledonous) 33. Seed germination- Process that transforms a seed into a seedling 34. Imbibition- The first step in seed germination; absorption of water 35. Radicle- Embryonic root that emerges from the seed 36. Plumule- Embryonic shoot that emerges from the seed and breaks through the soil surface 37. Epicotyl- Part of the plumule above the cotyledon 38. Hypocotyl- Part of the plumule below the cotyledon

INSTRUCTION (115 MINS) 1. Divide the class into groups of four and will assign each group to bring flowers and fruits to class. The flowers (particularly gumamela) and fruits will be used during the delivery of the lesson. 2. Describe the general life cycle of plants: The mature, multicellular organism is a diploid sporophyte. Later, some cells undergo meiosis to produce haploid gametes which are then released. Gametes fuse and form the zygote which develops by mitosis to become the multicellular diploid sporophyte. 3. In some plants, the dominant part of the life cycle is a multicellular, haploid gametophyte ( all cells have a haploid chromosome number). Mitosis releases individual cells that can act like gametes (gamete are produced by mitosis). The following terms should be mentioned: Gametophyte, Gametangia, Sporophyte, Sporangia GENERALIZED LIFE CYCLE OF PLANTS

152

4. Describe the different types of life cycles:

I. Haplontic life cycle A. Show life cycle of the green alga Chara i. Chara is a multicellular green alga related to higher plants because it has both chlorophyll a and b and produce plant starch. Its dominant stage is a multicellular haploid stage which produces gametes that eventually fuse to form unicellular zygotes. Each zygote then undergoes meiosis to become haploid, after which it undergoes mitosis to become the multicellular organism. II. Haplodiplontic life cycle A. Show life cycle of a moss (use figure 3 at the end of the document as reference) i.

A moss has a multicellular haploid (gametophyte) stage that produces gametes. These gametes fuse to produce a zygote that undergoes mitosis to produce a multicellular sporophyte. Within a part of the sporophyte called the capsule, cells undergo meiosis to produce meiospores. These spores are eventually released and germinate by dividing

mitotically to become a multicellular gametophyte. III. Diplontic life cycle A. Type of life cycle found in flowering plants (and in most animals). The organism is in the diploid stage ( all cells are diploid in chromosome number) except for mature, haploid sex cells which are called gametes.

LIFE CYCLE OF THE GREEN ALGA CHARA, DEPICTING A HAPLONTIC LIFE CYCLE WHERE THE DOMINANT STAGE IS A MULTICELLULAR HAPLOID ORGANISM (GAMETOPHYTE) AND THE ONLY DIPLOID STAGE IS THE ZYGOTE WHICH UNDERGOES MEIOSIS

5. The flower

I. The four major whorls A. Sepals B. Petals C. Stamen with Anther and Filament D. Carpels- with Stigma, Style, Ovary and Ovule II. Types of flowers based on the presence of the whorls A. Complete B. Incomplete

LIFE CYCLE OF A MOSS, DEPICTING A HAPLODIPLONTIC LIFE CYCLE WHERE BOTH THE DIPLOID (SPOROPHYTE) AND HAPLOID (GAMETOPHYTE) STAGES ARE MULTICELLULAR. THE MOSS PLANT PROPER IS A GAMETOPHYTE.

III. Types of flowers based on the presence of reproductive whorls A. Perfect / Bisexual B. Imperfect / Unisexual i. Staminate flower ii. Carpellate flower Exercise: use the exercise given at the end of this section to identify different floral parts. Plant types based on the presence of reproductive structures: Monoecious or Dioecious Development in flowering plants

I. Gametophyte - Development through gametogenesis (use figure 6 to illustrate gametogenesis in flowering plants) A. Male gametophyte - The microsporangium in the anther contains numerous microsporocytes. Each microsporocyte will undergo meiosis to produce four haploid microspores each microspore develops into a pollen grain (containing two sperm nuclei and one tube nucleus) B. Female gametophyte - The megasporangium in the ovule contains megasporocytes. One megasporocyte will undergo meiosis to produce four haploid megaspores three megaspores degenerate remaining megaspore divides mitotically three times, an embryo sac with eight haploid nuclei membranes partition to make the embryo sac multicellular

GAMETOGENESIS IN FLOWERING PLANTS

II. Pollination A. Transfer of pollen grain from the anther to the stigma B. May be animal-aided or wind-aided III. Double fertilization A. Inside a pollen grain there is a tube cell and generative cell generative cell divides to produce two sperm cells while the tube cell becomes pollen tube pollen tube elongates along the style and penetrates the ovule in the ovary via the micropyle (an opening) pollen tube discharges the sperm cells into the embryo sac inside the ovule one sperm unites with the egg to form the zygote while the other sperm fuses with the polar nuclei to become the endosperm, which serves as food of the early embryo 154

DOUBLE FERTILIZATION IN FLOWERING PLANTS

IV. Embryo development (embryogenesis) A. Zygote divides mitotically to produce the proembryo and suspensor, which anchors the proembryo and transfers nutrients from the parent plant to it cotyledons appear on the proembryo (monocots have onlyone cotyledon whereas dicots havetwo) proembryo elongates into an embryo. V. Maturation of ovary and ovule A. Ovary matures into fruit while the ovule becomes the seed. The seed may become dormant for some time. VI. Seed germination A. Transformation of seed to seedling B. Seed undergoes imbibition to break dormancy nutrients stored in the endosperm or cotyledons are digested and transferred to the growing regions of the embryo to primary meristems (protoderm, ground meristem, procambium) develop to radicle emerges to plumule breaks through the soil surface LIFE CYCLE OF FLOWERING PLANTS

i.

Epigeal germination occurs when the cotyledon emerges above ground, thereby exposing the hypocotyl of the plumule.

ii. Hypogeal germination occurs when the cotyledon remains below ground, thereby concealing the hypocotyl. VII. Seedling growth to mature plant A. Primary meristems differentiate to become the different plant tissues

TYPES OF GERMINATION

Teacher Tip:

ENRICHMENT

1. What could be the significance of the ability of flowering plants to produce seeds? What advantages does a seed provide? 2. What is the advantage of having seeds covered in fruits?

Seeds can be dormant when conditions become harsh or dry, then germinate when conditions become favorable, i.e. presence of moisture. Fruits allow better dispersal of the seeds in order to minimize competition for resources with their parents. Fruits encourage animals to consume them, discarding the seeds in the process. Other fruits physically disperse the seeds, as seen in the “wings” of the fruits of dipterocarps, also known as samara.

EXERCISE ON PLANT REPRODUCTION

Materials

1. Gumamela flower 2. Scalpel blade or sharp pencil 3. Optional: other available flowers Procedure

1. Obtain a flower of gumamela (Hibiscus rosa-sinensis). 2. Locate the outermost floral whorl. You can find it at the base of the flower and resembles a green crown. These are the sepals, collectively called the calyx. Inner to the sepals but extending beyond them are the prominent petals, collectively known as the corolla. 3. At the center of the flower is a prominent tube. This is called the staminal tube. Surrounding the tube are minute stalks with yellow bulbous tips. These are the stamens. The bulbous tips are the anthers containing the microsporangia while the stalks are the filaments. 4. At the very tip of the staminal tube are five bulbous structures, each borne on a stalk that fuses with the other stalks as they go down the staminal tube. The structures at the tips are the stigmas of the carpels while the stalks are the style. 5. Remove the petals carefully so as not to damage the base. Using a scalpel blade or the sharp end of a pencil, make an incision from the tip of the staminal tube down to the base. Carefully open the staminal tube to reveal the rest of the fused styles. Follow the styles until they terminate at the base. This base is the ovary. 6. Draw the flower and label the following parts: petals, sepals, stamens, anther, filament, carpels, stigma, style, and ovary.

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7. Optional investigation: do the same for other flowers available. Draw and label the parts. Using all the flowers used in this exercise, classify them as to whether they are complete or incomplete, perfect or imperfect. Table 1. Fates of the primary meristems in flowering plant development P R I M A RY M E R IS T E M

M AT U R E T I S S U E

Protoderm

Epidermis

Groundmeristem

Cortex,pith

Procambium

Primary xylem, primary phloem, vascular cambium, cork cambium, secondary meristems

General Biology 2

60 MINS

Lesson 18.1: Compare and Contrast Process in Plants and Animals: Nutrient Procurement and Processing (1 of 3) Content Standard

LESSON OUTLINE

The learners demonstrate an understanding of plant and animal organ systems for nutrient procurement and processing and their functions.



Motivation

Review Physiological Processes


Instruction

Lecture on Plant Nutrition

25

Practice Enrichment

Drawing Activity or Laboratory Work Quiz

15 5

Evaluation

Assignment

•

enumerate the structures or organs involved in nutrient procurement and

•

processing in plants and animals; describe the functions of structures or organs involved in nutrient procurement and processing; and

•

explain how food is processed in a mammalian digestive system

5 5

5

Materials

Learning Competency

The learners shall be able to compare and contrast nutrient procurement and processing in plants and animals. STEM_BIO11/12-IVa-h-1

Microscopes and slides of monocot and dicot root cross sections. In the absence of microscopes, visual aids on monocot and dicot root cross sections.

Resources



define nutrient and cite the nutritional requirements of plants and animals;

•

enumerate nutritional adaptation by plants and feeding mechanisms in animals;

•

distinguish different kinds of digestive compartments in animals; and

•

trace the pathway of food processing in a mammalian/human digestive system. 158

(1) Barrion AA, Tudor MFVA, Colle MCD, Reamillo MCS, and MAP Robles. 2000. BIOLOGY II Laboratory Manual: An Investigative Approach. Institute of Biological Sciences, College of Arts and Sciences, UP Los Baños. ISBN 971-547-099-8. 140p. (2) Johnson GB and PH Raven.1996. BIOLOGY: Principles and Explorations.Austin, USA: Holt, Rinehart and Winston. 1072p. (3) Reece JB, Urry LA, Cain ML, Wasseman SA, Minorsky PV, and RB Jackson. Campbell Biology. Tenth Edition. Boston, USA: Pearson Education, Inc. 1279p. (4) Starr C and R Taggart. 2004. BIOLOGY: The Unity and Diversity of Life. Tenth Edition. Australia: Thomson – Brooks/Cole. 933p.


1. Give the overview of the lesson by enumerating the learning objectives. 2. Present the topic outline for Nutrient Procurement and Processing. An example is given below: I. Plant Nutrition A. Nutritional requirements of plants B. Routes for absorption of water and minerals across the roots C. Nutritional adaptations by plants II. Animal Nutrition A. Nutritional requirements of animals

Teacher Tip The teacher may engage the attention of students by bringing food (e.g. fruits, nuts, biscuits, etc.) to the class as an introduction for nutrition.

Teacher Tip The topic on Nutrient Procurement and Processing can be divided into three parts, with one-hour session being allotted for each part. Part I. Plant Nutrition (1 hour) Part II. Animal Nutrition (1 hour) Part III. The Human Digestive System (1 hour)

B. Food uptake in cells C. Variations in feeding mechanisms and digestive compartments in animals III. The Human Digestive System

MOTIVATION (5 MINS) Recall Physiological Processes

Teacher tip

1. Ask the students what they think are the important activities for the maintenance of life. Sample responses: eating, breathing, ability to respond to stimuli.

In relation to the questions asked, the following concepts may be integrated to answers given by the class: • Maintenance functions refer to the various physiological processes that occur in an organism necessary for the maintenance of life. • Some physiological processes for the maintenance of life include: nutrient procurement and processing, gas exchange, internal transport, and regulation of body fluids among others. • Maintenance functions help the organism attain homeostasis, that is, the state of stable equilibrium in a biological system.

2. Ask them to enumerate the kinds of nutrients that organisms obtain from food. Sample responses: proteins, fats, carbohydrates, vitamins, minerals. 3. Ask them to recite the different organs in the animal body that may be involved in digestion. Sample responses: teeth, tongue, stomach, small intestine.


Misconception:

Lecture on Plant Nutrition

1. Define nutrient and enumerate the two types of organisms based on mode of nutrition. I. Nutrient– refers to any substance required for the growth and maintenance of an organism. The two types of organisms based on the mode of nutrition are: A. autotrophs– organisms that obtain energy from sunlight and chemicals to produce their own food. Examples: plants; chemosynthetic bacteria B. heterotrophs– organisms that cannot make their own food and obtain their energy from other organisms. Examples: animals, fungi 2. Identify the nutritional requirements of plants: A. water B. carbon dioxide Further, note that water and carbon dioxide are the raw materials needed for photosynthesis, the process by which plants convert the energy from sunlight into chemical energy. – which include macronutrients which are normally C. essential nutrients or elements required in amounts above 0.5% of the plant’s dry weight; and micronutrients which are required in minute or trace amounts; : C, H, O, N, K, Ca, Mg, P, S D. examples of macronutrients E. examples of micronutrients: Cl, Fe, B, Mn, Zn, Co, Mo 3. Distinguish between the routes for the absorption of water and minerals across plant roots: A. symplast route– through plasmodesmata – along cell walls B. apoplast route Note that the water and minerals from the soil need to reach the conducting tissues of plants, specifically the xylem. The two routes mentioned show how this can happen.

160

Students may think that plants are self- sufficient in terms of nutrition. Emphasize that although plants are capable of producing their own food (autotrophic organisms) through p hotosynthesis, they also require the raw materials from the environment for the maintenance of life: water, carbon dioxide, and minerals.

Teacher Tips The significant role of essential nutrients in plants can be highlighted by showing pictures of plants with mineral deficiencies or by enumerating symptoms or manifestations of mineral deficiencies. A visual aid on the cross section of a root showing the two routes will be helpful to the learners. The different layers of cells should be illustrated and labelled: epidermis, cortex, endodermis, Casparian strip, vascular cylinder (xylem and phloem)

4. Cite specialized absorptive structures: A. root hairs– slender extensions of specialized epidermal cells that greatly increase the surface area available for absorption. B. root nodules– localized swellings in roots of certain plants where bacterial cells exist symbiotically with the plant. The bacteria help the plant fix nitrogen and in turn, the bacteria are able to utilize some organic compounds provided by the plant. – a symbiotic interaction between a young root and 3. mycorrhizae (singular, mycorrhiza) a fungus. The fungus obtains sugars and nitrogen-containing compounds from root cells while the plant is able to get some scarce minerals that the fungus is better able to absorb from the soil. 5. Enumerate nutritional adaptation by plants: A. Symbiosis of plants and soil microbes B. Symbiosis of plants and fungi C. Parasitism D. Predation

PRACTICE (15 MINS) Drawing Activity or Laboratory Work

6. For those with microscopes, observe slides of monocot root and dicot root cross sections. For those without microscopes, visual aids for monocot and dicot root cross sections may be shown on the board. Ask the students to do the following: A. Draw the monocot and dicot root cross sections. B. For each, label the epidermis, cortex, endodermis, Casparian strip, xylem and phloem. C. On the drawing, use a red ball pen to trace the symplast route, and a blue ball pen to trace the apoplast route for the movement of water from the soil to the xylem.

Teacher Tips Letting the students draw and trace the routes of movement of water and minerals reinforce the concept of absorption through plant roots.

ENRICHMENT (5 MINS) Quiz

1. What is a nutrient? 2. Give the difference between: A. autotrophs and heterotrophs B. apoplast and symplast routes C. macronutrients and micronutrients 3. What is the significance of having root hairs in plant roots? 4. How do plants benefit from symbiotic associations with bacteria? With fungi?

EVALUATION (5 MINS) Quiz

1. Carbon, hydrogen, oxygen, nitrogen, and potassium are examples of ______ for plants. A. macronutrients B. micronutrients C. trace elements D. essential elements E. both a and d

Teacher Tips

2. The nutrition of some plants depends on a root-fungus association known as a ______. A. root nodule B. mycorrhiza C. root hair D. root hypha

162

Letting the students draw and trace the routes of movement of water and minerals reinforce the concept of absorption through plant roots.

3. Th]]]e nutrition of some plants depends on a root-bacterium association known as a ______. A. root nodule

Answer Key:

B. mycorrhiza C. root hair

1. e 2. 2.

D. root hypha

3. b 3 4. 4 a

4. Plants are autotrophic organisms and therefore do not require raw materials from the environment. True or False. 5. Certain plants may acquire nutrients from other organisms through parasitism or predation. True or False. Assignment

6. Give three examples of nutrient deficiencies in plants and the corresponding symptoms. 7. What is the role of the Casparian strip present in endodermal cells? 8. Research on examples of parasitic plants and predator plants. Give an example for each. What structural adaptations are present in these plants that allow them to acquire nutrition through parasitism and predation? Tabulate answers by using three columns with the following criteria: Type of Adaptation (parasitism or predation), Example Plant, and Structural Adaptation. ASSESSMENT GUIDE (FOR THE ACTIVITY AND LABORATORY WORK)

A. 1. (POOR) – disorganized drawing with many errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. B. 2. (SATISFACTORY)– acceptable drawing with some errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. C. 3. (VERY GOOD)– clear drawing with minimal error in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. D. 4. (EXCELLENT)– clear drawing with correct labels for the cell layers in the root cross sections; and accurate tracing of the apoplast and symplast routes.

5. False. Plants need to acquire water from the soil through roots and carbon dioxide from the air through leaves. Both water and carbon dioxide are needed for photosynthesis. 5. True.

General Biology 2

60 MINS


LESSON OUTLINE

The learners demonstrate an understanding of plant and animal organ systems for nutrient procurement and processing and their functions.



Motivation

Observe Nutrition Facts

Instruction

Lecture on Animal Nutrition

25

Practice

Drawing Activity or Laboratory Work

20

Enrichment

Quiz

5

Evaluation

Assignment

5



•


•


2 3

Materials

Learning Competency

The learners shall be able to compare and contrast nutrient procurement and processing in plants and animals. STEM_BIO11/12-IVa-h-1 Specific Learning Outcomes

Microscopes and slides of Paramecium, Hydra, or Planaria. In the absence of microscopes and slides, visual aids of the mentioned specimens may be used. Also, visual aids of an insect’s digestive system and a toad’s digestive system; if available, dissecting pan and d issecting kit.

Resources


define nutrient and cite the nutritional requirements of plants and animals;

•

enumerate nutritional adaptation by plants and feeding mechanisms in animals;

•

distinguish different kinds of digestive compartments in animals; and

•

trace the pathway of food processing in a mammalian/human digestive system. 164

(1) Barrion AA, Tudor MFVA, Colle MCD, Reamillo MCS, and MAP Robles. 2000. BIOLOGY II Laboratory Manual: An Investigative Approach. Institute of Biological Sciences, College of Arts and Sciences, UP Los Baños. ISBN 971-547-099-8. 140p. (2) Johnson GB and PH Raven.1996. BIOLOGY: Principles and Explorations.Austin, USA: Holt, Rinehart and Winston. 1072p. (3) Reece JB, Urry LA, Cain ML, Wasseman SA, Minorsky PV, and RB Jackson. Campbell Biology. Tenth Edition. Boston, USA: Pearson Education, Inc. 1279p. (4) Starr C and R Taggart. 2004. BIOLOGY: The Unity and Diversity of Life. Tenth Edition. Australia: Thomson – Brooks/Cole. 933p.


1. Present the topic outline for Nutrient Procurement and Processing. An example is given below: I. Plant Nutrition A. Nutritional requirements of plants B. Routes for absorption of water and minerals across the roots C. Nutritional adaptations by plants

Teacher Tip The topic on Nutrient Procurement and Processing can be divided into three parts, with one-hour session being allotted for each part.

Part I. Plant Nutrition (1 hour) Part II. Animal Nutrition (1 hour) Part III. The Human Digestive System (1 hour)

II. Animal Nutrition A. Nutritional requirements of animals B. Food uptake in cells C. Variations in feeding mechanisms and digestive compartments in animals III. The Human Digestive System

MOTIVATION (3 MINS) Observe Nutrition Facts

1. Ask the learners to locate the table on Nutrition Facts on the package of the food or snack that they brought in class. 2. Call one or two learners to read aloud the kinds of nutrients listed in the Nutrition Facts table. Example: A 100 g foil pack of peanuts may show the following kinds of nutrients: Fat, Cholesterol, Carbohydrate, Protein, Sodium, Vitamins, Minerals e.g. Iron 3. Ask the class what we need to eat and why. Example: what we need to eat – rice, potato, meat, fish, fruits, vegetables, etc. why we need to eat – to obtain energy for our activities, to grow, to provide our bodies with materials for making bone and muscles, etc.

Teacher Tip You may assign the learners to bring food or snack packed in foil or plastic that shows a table on Nutrition Facts. The different kinds of nutrients listed in the Nutrition Facts table are among the nutritional requirements of animals.


Teacher Tip:

Lecture on Animal Nutrition

You may ask the learners to check the amount of calories indicated in the Nutrition Facts table of the food they brought.

1. Introduce the concept of calories from food. A Calorieis a unit of energy that indicates the amount of energy contained in food. It specifically refers to the amount of heat energy required to raise the temperature of 1 kg (2.2 lb.) of water by 1oC (1.8oF). The greater the number of Calories in a quantity of food, the greater energy it contains (Johnson and Raven, 1996). 2. Identify the nutritional requirements of animals:

Teacher Tips:

I. Carbohydrates– serve as a major energy source for the cells in the body. These are usually obtained from grains, cereals, breads, fruits, and vegetables. On average, carbohydrates contain 4 Calories per gram. II. Proteins– can also be used as an energy source but the body mainly uses these as building materials for cell structures and as enzymes, hormones, parts of muscles, and bones. Proteinsproteins come from products, poultry, fish, meat, and grains. Like carbohydrates, also dairy contain 4 Calories per gram. III. Fats – are used to build cell membranes, steroid hormones, and other cellular structures; also used to insulate nervous tissue, and also serve as an energy source. Fats also contain certain fat- soluble vitamins that are important for good health. Fats are obtained from oils, margarine, butter, fried foods, meat, and processed snack foods. They contain a higher amount of energy per gram than carbohydrates or proteins, about 9 Calories per gram. IV. Essential Nutrients – include substances that animals can only get from the foods they eat because they could not be synthesized inside the body. These include: – needed for synthesis of proteins and enzymes; among the 20 A. Essential amino acids amino acids, eight could not be synthesized by humans: lysine, tryptophan, threonine, methionine, phenylalanine, leucine, isoleucine and valine. – used for making special membrane lipids; an example is B. Essential fatty acids linoleic acid in humans. C. Vitamins– organic molecules required in small amounts for normal metabolism; examples include fat-soluble Vitamins A, D, E, K, and water-soluble Vitamins B, B2, B3, B12, C. 166

Carbohydrates, proteins, and fats are energy-rich compounds present in food. The energy in food is stored in in its chemical bonds. As body cells break the chemical bonds, energy is harvested to make ATP. Essential amino acids, vitamins, and trace elements are important substances for good health. Essential amino acids serve as building blocks for proteins, while vitamins and trace elements are necessary for many cellular chemical reactions. The significant role of essential nutrients in animals can be highlighted by citing examples of t he effects of certain nutrient deficiencies or extreme excess. This may also be given as an assignment to learners to enhance their appreciation of proper nutrition. Examples include: rickets, scurvy, goiter, etc.

– inorganic nutrients needed by the body in minute D. Trace Elements or Minerals amounts; these form part of enzymes, body tissues, and body fluids; examples include: iodine, cobalt, zinc, molybdenum, manganese, selenium.

Teacher Tip: Pictures of phagocytosis and pinocytosis can be shown in class.

3. Describe food uptake in cells via the three types of endocytosis: I. phagocytosis– engulfment of organic fragments or big particles, eg. pseudopod formation in Amoeba. II. pinocytosis– uptake of extracellular fluid by a cell using small vesicles derived from the plasma membrane. – this relies on membrane receptor recognition of III. receptor-mediated endocytosis specific solutes which are then taken up by the cell via receptor-coated pits. 4. Cite the different types of animals based on feeding mechanisms: – animals that live in or on their food source. Examples: earthworms I. substrate-feeders that feed through the soil where they live in; caterpillars that eat through the leaves where they live on. II. filter-feeders– include many aquatic animals which draw in water and strain small organisms and food particles present in the medium. Examples: whales and coelenterates III. fluid-feeders– suck fluids containing nutrients from a living host. Examples: mosquitoes, leeches, head lice, aphids IV. IV. bulk-feeders– eat relatively large chunks of food and have adaptations like jaws, teeth, tentacles, claws, pincers, etc. that help in securing the food and tearing it to pieces. Examples: snakes, cats, man 5. Enumerate the different kinds of digestive compartments in animals: – these fuse with lysosomes that contain I. Food vacuoles in unicellular organisms hydrolytic enzymes. Example: food vacuole in a protozoa like Paramecium

Teacher Tips: Consider a frog’s complete digestive system. The parts between the mouth and anus are: pharynx, esophagus, stomach, small intestine, and l arge intestine.

– composed of a single II. Gastrovascular cavity or incomplete digestive system opening through which food is taken in and where wastes are disposed of; it is a saclike body cavity. Examples: in the cnidarianHydra and in flatworm Planaria – essentially like a tube with an opening at one end for III. Complete digestive system taking in food (mouth) and an opening at the other end where unabsorbed waste materials are eliminated (anus). In between the mouth and anus, are specialized organs that carry out transport, processing, and absorption of digested nutrients. 6. Describe the accessory organs for digestion in a complete digestive system: I. liver – secretes bile for emulsifying fats II. gallbladder– stores bile produced by the liver III. pancreas– secretes enzymes that break down all major food molecules; secretes buffers against HCl from the stomach; secretes the hormone insulin for control of glucose metabolism

PRACTICE (20 MINS)

Teacher Tip:


1. Observe and draw a Paramecium as seen under the microscope or from a visual aid. Label the food vacuole.

Letting the learners draw the structures for digestion allows them to compare different types of digestive compartments in different animals.

2. Observe and draw a Hydra or Planaria as seen under a microscope or from a visual aid. Label the gastrovascular cavity. 3. Draw from a visual aid the complete digestive system of an invertebrate such as a cockroach or grasshopper. Label the parts such as: salivary glands, esophagus, crop, gizzard, gastric caeca, mesenteron, Malpighian tubules, small intestine (ileum), large intestine (colon), rectum, and anus. 4. Pith and dissect a toad. Observe the following organs: mouth or buccal cavity, tongue, pharynx, esophagus, stomach, small intestine, large intestine (colon), cloaca, anus. Also find the accessory organs: liver, gallbladder, pancreas. Draw and label all the parts. If dissection will not be done, let the learners copy and draw from a visual aid.

168

ENRICHMENT (5 MINS)

Teacher Tip:

Quiz

The answers to the review questions can be found in the lecture given by the teacher.

1. State several reasons why carbohydrates are usually needed in more amounts than fats in the diet. 2. Explain why protein should be included in the diet. 3. What will happen to the human body if we are deficient in particular vitamins and trace elements? Give examples of effects of vitamin and mineral deficiencies. 4. There are 20 amino acids needed to make proteins in the animal body. Why aren’t they all considered essential to animal diets? 5. Compare incomplete and complete digestive systems. 6. What are the functions of accessory organs in a complete digestive system?

EVALUATION (5 MINS) 1. State the average amount of energy obtained from the following nutrients in terms of Calories: 1 g of carbohydrate _______ Calories 1 g of protein _______ Calories 1 g of fat _______ Calories 2. Of the 20 amino acids used to make proteins in the human body, _______ must be obtained through food. 3. The two main groups of vitamins include those soluble in _______ and in _______. 4. _______ refer to inorganic nutrients needed by the body in minute amounts. 5. Cells take up food via the process of _______. 6. In terms of feeding mechanisms, earthworms are considered _______, while humans are considered _______. 7. A gastrovascular cavity is considered an incomplete digestive system. True or False. 8. A complete digestive system is characterized by the presence of a mouth at one end and anus at the other end. True or False.

Answer : 4, 4, 9Key Calories, respectively 1. 2. Eight

3. Oil, water (or vice versa) 4. Trace elements or minerals 5. endocytosis 5.

Substrate-swallowers,

6. True 7. True

food-seekers

ASSIGNMENT

Teacher Tip:

1. List four water-soluble vitamins and four oil-soluble vitamins. Present in a tabular form their roles, food sources, and effects of deficiency.

Answers to the assignment may be written on bond paper and submitted on the following meeting.

2. Cite five trace elements or minerals. Tabulate their food sources and roles. 3. What are the roles of the following parts of an insect’s digestive system: crop, gizzard, Malpighian tubules. 4. Enumerate the parts of the toad’s digestive system and give the function of each. 5. Define malnutrition. Are the conditions of undernutrition and obesity considered malnutrition? Explain. Teacher Tips:

ASSESSMENT GUIDE (FOR THE ACTIVITY AND LABORATORY WORK) 1. (POOR) – disorganized drawing with many errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 2. (SATISFACTORY)– acceptable drawing with some errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 3. (VERY GOOD)– clear drawing with minimal error in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 4. (EXCELLENT)– clear drawing with correct labels for the cell layers in the root cross sections; and accurate tracing of the apoplast and symplast routes.

170

Some questions in the assignment may be included for assessment, in addition to the drawings done during the laboratory work.

General Biology 2

60 MINS


The learners demonstrate an understanding of plant and animal organ systems for nutrient procurement and processing and their functions. Performance Standard


LESSON OUTLINE


2

Motivation

The Digestive System Lecture on the Digestive System

30 15

3

•


Instruction


Practice


•

Enrichment

Quiz

5


Evaluation

Assignment

5

•

Learning Competency

Materials

The learners shall be able to compare and contrast nutrient procurement and processing in plants and animals. STEM_BIO11/12-IVa-h-1

Microscopes and slides of a vertebrate small intestine cross-section. In the absence of microscopes and slides, visual aids of the mentioned specimen may be used.


Resources


(1) Barrion AA, Tudor MFVA, Colle MCD, Reamillo MCS, and MAP Robles. 2000. BIOLOGY II Laboratory Manual: An Investigative Approach. Institute of Biological Sciences, College of Arts and Sciences, UP Los Baños. (2) Brooker RJ, Widmaier EP, Graham LE, Stiling PD. 2008.Biology. Boston: McGraw- Hill. 1300 pp. (3) Johnson GB and PH Raven.1996. BIOLOGY: Principles and Explorations.Austin, USA: Holt, Rinehart and Winston. 1072p. (4) Reece JB, Urry LA, ,Wasserman SA, Minorsky PV, Jackson RB. 2011. Campbell Biology (10th Edition). US: Benjamin Cummings. 1488 pp. (5) Starr C and R Taggart. 2004. BIOLOGY: The Unity and Diversity of Life. Tenth Edition. Australia: Thomson – Brooks/Cole. 933p.

•

enumerate and describe the main stages of food processing;

•

describe the organs involved in food processing in the human digestive system and their roles;

•

summarize the mechanisms of digestion, absorption, and delivery of nutrients into cells;

•

explain the regulation of digestion; and

•

cite some health problems associated with the digestive system.

INTRODUCTION (2 MINS) Teacher Tip


1. Present the topic outline for Nutrient Procurement and Processing. An example is given below: I. Plant Nutrition A. Nutritional requirements of plants

The topic on Nutrient Procurement and Processing can be divided into three parts, with one-hour session being allotted for each part. Part I. Plant Nutrition (1 hour) Part II. Animal Nutrition (1 hour) Part III. The Human Digestive System (1 hour)

B. Routes for absorption of water and minerals across the roots C. Nutritional adaptations by plants II. Animal Nutrition A. Nutritional requirements of animals B. Food uptake in cells C. Variations in feeding mechanisms and digestive compartments in animals III. The Human Digestive System

Teacher tip

2. Cite the Specific Learning Outcomes for this topic.

You mayinassign students to bring food on or snack packed foil orthe plastic that shows a table Nutrition Facts.

MOTIVATION (3 MINS) The Digestive System

1. The usual way of presenting food processing in the human digestive system is to follow the fate of food as it passes from mouth to anus. 2. A figure or diagram of the human digestive system may be presented to class as an overview of the components and processes of the digestive system. 3. Demonstrate peristalsis by placing a ball inside a stocking and squeezing to move it along.

INSTRUCTION (30 MINS) Lecture on the Digestive System

1. Enumerate and describe the main stages of food processing: A. Ingestion– the act of eating or feeding; this is coupled with the mechanical breakdown of food into smaller pieces allowing for a greater surface area for chemical digestion. B. Digestion– breakdown of food into particles, then into nutrient molecules small enough 172

The different kinds of nutrients listed in the Nutrition Facts table are among the nutritional requirements of animals.

to be Chemical digestion by enzymes involves breaking of chemical bonds through the addition of water, i.e., enzymatic hydrolysis.

Note to the Teacher

C. Absorption– passage of digested nutrients and fluid across the tube wall and into the body fluids; the cells take up (absorb) small molecules such as amino acids and simple sugars.

The lecture for this part is quite long; some details may be omitted in the delivery. A handout on the lecture may be given to the students so that time may be devoted to listening to the teacher instead of copying the lecture.

D. Elimination–expulsion of the undigested and unabsorbed materials from the end of the gut.

Teacher Tips:

2. Describe the organs involved in food processing in the human digestive system: A. The Oral Cavity, Pharynx, and Esophagus I. Oral Cavity– it is where food is initially chewed into shreds by the teeth, and mixed with saliva by the tongue. Saliva is secreted into the mouth by three pairs of salivary glands located above the upper jaw and below the lower jaw. II. Pharynx–the region in the back of the throat that serves as the entrance to the esophagus that connects to the stomach and trachea (windpipe) that serves as airway to the lungs. To block breathing as food leaves the pharynx, a flap-like valve (the epiglottis) and the vocal cords close off the trachea. III. Esophagus– connects the pharynx with the stomach. No digestion takes place within the esophagus but the contractions within its muscular wall propel the food past a sphincter, into the stomach. The rhythmic waves of contraction of the smooth muscle wall of the esophagus are called peristaltic contractions or peristalsis. The esophagus is about 25 cm (10 in.) long.

Regardless of the variations in the structures of a complete digestive system ( eg.digestive system of a toad versus that of a bird), there are four distinct stages of food processing that are carried out. These are: ingestion, digestion, absorption, and elimination. Saliva has several components. It contains an enzyme (salivary amylase), a buffer ( bicarbonate), slippery glycoproteins (mucins), and antimicrobial agents such as lysozyme. A sphincter is a ring of smooth muscles that close off a passageway or an opening to the body surface. The stomach secretes about 2 L of HCl every day, rendering a very low pH in the stomach (between 1.5 and 2.5), about 3 million times more acidic than the bloodstream. Ask

B. The Stomach I. The stomachis a muscular, stretchable sac located just below the diaphragm. It has three important functions. First, it mixes and stores ingested food. Second, it secretes gastric juice that helps dissolve and degrade the food, particularly proteins. Third, it regulates the passage of food into the small intestine. II. The gastric juiceis a combination of HCl and acid-stable proteases. III. The churning action of the stomach together with the potent acidity of the gastric juice convert food into a thick, liquid mixture called chyme.

the students to research on how the gastric juice can facilitate chemical digestion.

C. Small Intestine I. The small intestineis approximately 6 meters long and is composed of three regions: the duodenum, jejunum, and ileum. II. It is where most enzymatic hydrolysis of the macromolecules from food occurs. The complete digestion of carbohydrates, fats, and proteins occurs in the duodenum, about the first 25 cm. of the small intestine. III. The rest of the small intestine is devoted to absorbing water and the products of digestion into the bloodstream. IV. Absorption of the end products of digestion takes place in the ileum, the surface area of which is increased by villi and microvilli. D. The Accessory Digestive Organs – review the functions discussed in previous I. Pancreas, Liver, and Gallbladder meeting. E. The Large Intestine or Colon I. The large intestineis much shorter than the small intestine, about 1 meter. II. It concentrates and stores undigested matter by absorbing mineral ions and water. A small amount of fluid, sodium, and vitamin K are absorbed through its walls. III. Unlike the small intestine, it does not coil up and does not have villi and has only onethirtieth of the absorptive surface area of the small intestine. IV. Many bacteria live and thrive within the large intestine where they help process undigested material into the final excretory product, feces. F. The Rectum and Anus I. The rectumis a short extension of the large intestine and is the final segment of the digestive tract. It is where the compacted undigested food from the colon are pushed via peristaltic contractions. II. The distention of the rectum triggers expulsion of feces. III. The anus is the terminal opening of the digestive system through which feces are expelled.

174

Teacher Tip: The gut wall consists of four tissue layers surrounding a central cavity –the lumen. In contact with the lumen is the mucosa, followed by the submucosa, circular muscle layer, longitudinal muscle layer, and serosa.

3. Summarize the mechanisms of digestion and absorption: A. Carbohydrate digestion begins in the mouth but could not continue in the stomach due to the acidic pH that destroys the amylase. It resumes in the small intestine where the resulting monosaccharides are absorbed. B. Proteins are digested in the stomach and small intestine. Resulting amino acids are absorbed in the small intestine where they leave the intestinal cell and enter the blood through a facilitated diffusion carrier in the plasma membranes on the opposite side. C. Fat digestion occurs entirely in the small intestine. Although fatty acids and monoglycerides enter epithelial cells from the intestinal lumen, it is triglycerides that are released on the other side of the cell and carried by blood capillaries to be transported throughout the body. D. Most water-soluble vitamins are absorbed by diffusion or active transport. Fat-soluble vitamins follow the pathway for fat absorption. 4. Describe how nutrients are delivered into cells: A. Substances pass through the brush border cells that line the free surface of each villus by active transport, osmosis, and diffusion across the lipid bilayer of plasma membranes. B. The nutrients then proceed into the internal environment and pass to the blood which is collected into the hepatic portal vein leading to the liver. C. After flowing through the liver, the blood carrying the nutrients passes into the hepatic vein which carries the blood back to the heart to be distributed to the different body tissues. 5. Explain the regulation of digestion: A. The digestive system of animals is regulated in part by other organ systems, especially the nervous and endocrine systems. B. The nervous system exerts control on the digestive system in two ways: I. regulation of muscular and glandular activity by the local nerves in the alimentary canal; and II. long-distance regulation by the brain. C. Hormones regulate the rate of digestion.

Teacher Tip: Emphasize that digestion and absorption are inseparable in the total function of providing nutrition to body cells.

6. Cite some health problems associated with nutrition and digestive system: A. Frequent complaints associated with the gastro-intestinal tract include heart burn, ulcers, and diarrhoea.

PRACTICE (20 MINS) Drawing Activity or Laboratory Work

1. As an alternative to a pure lecture discussion, questions related to the anatomy or function of each organ or component may be asked. As each digestive organ is discussed, reference to an overhead transparency or visual can be done. 2. For example: In relation to the oral cavity, ask the students what other structures or secretions may be found and cite the possible function of each in relation to digestion. 3. Sample answers: teeth, tongue, saliva – cite the functions of each; proceed to the succeeding parts of the digestive system 4. Ask the students to observe and draw a cross-section of the vertebrate small intestine (either from a microscopic slide viewed under scanner objective or a visual aid) and label the following components from the inner to outer layer:mucosa, submucosa, circular muscle layer, longitudinal muscle layer, and serosa. 5. If using a microscope to view the small intestine cross-section, shift to the low power objective (LPO) and focus on the infoldings of the mucosa which make up the villi. Draw and label. 6. Also present but could not be seen under an ordinary microscope are the numerous cytoplasmic extensions of the cells lining a villus, which are called microvilli. Keeping in mind the major functions of the small intestine, what is the significance of the presence of villi and microvilli?

ENRICHMENT (5 MINS) Conceptual Questions

1. Distinguish between digestion and absorption. 2. Give some reasons why dietary fiber which can come from fruits and vegetables, is so important in our diet. 176

EVALUATION (5 MINS) 1. The pancreas connects to which part of the alimentary canal? A. Esophagus B. Stomach C. Small intestine D. Cecum E. Large intestine 2. Which of the following statements regarding the vertebrate stomach is not correct? A. Its cells secrete the protease enzyme pepsin. B. It is a saclike organ that evolved to store food. C. Its cells secrete hydrochloric acid. D. It is the initial site of protein digestion. E. Absorption of many nutrients occurs there. 3. Absorption in the small intestine is increased by : A. B. C. D. E.

The many villi that are present on the inner surface of the small intestine. The brush border formed by microvilli on the cells of the villi. The presence of numerous transporter proteins on the epithelial cells. All of the above. None of the above.

4. Which of the following is a function of the large intestine? A. It participates in cellulose digestion by microbes that exist in the cecum of herbivores. B. It stores and concentrates fecal material. C. Its cells absorb salts and water that remain in chyme after it leaves the small intestine. D. Its cells absorb certain vitamins. E. All of the above. 5. Which of the following is correct? A. Carbohydrate digestion starts in the mouth and resumes in the small intestine. B. Protein digestion occurs only in the small intestine. C. Fat digestion occurs in the stomach and small intestine. D. Both water-soluble and fat-soluble vitamins are absorbed by diffusion or active transport. E. All of the above.

Answer Key:

1. C 2. E 3. D 4. E 5. A The teacher may add more items to the quiz to be taken from the lecture material or books with end of chapter review questions.

Assignment

1. Enumerate the major digestive enzymes for carbohydrate, protein, fat, and nucleic acid digestion. Tabulate as follows: ENZYME / SOURCE ORGAN / WHERE ACTIVE / SUBSTRATE / MAIN BREAKDOWN PRODUCTS 2. What contributes to the absorption capacity of the small intestine? 3. Why doesn’t gastric juice destroy the stomach cells that make it?

Note to the Teacher: Answers to the assignment may be written on bond paper and submitted on the following meeting. Answers to the assignment may be found in Reece et al., 2011; Starr and Taggart, 2004, and; any General Biology book.

4. What are the cells making up the gastric glands of the stomach? 5. Describe the following ailments associated with the digestive system and identify their causes: A. Gastric ulcers B. Acid reflux C. Heartburn ASSESSMENT GUIDE (FOR THE ACTIVITY AND LABORATORY WORK NUMBERS 2 AND 3 INVOLVING DRAWING LABELING)

1. (POOR) – disorganized drawing with many errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 2. (SATISFACTORY)– acceptable drawing with some errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 3. (VERY GOOD)– clear drawing with minimal error in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 4. (EXCELLENT)– clear drawing with correct labels for the cell layers in the root cross sections; and accurate tracing of the apoplast and symplast routes. ASSESSMENT GUIDE (FOR QUIZ AND ASSIGNMENT): THE TEACHER MAY ASSIGN POINTS TO THE QUESTIONS

1. (POOR) – 74% and below 2. (FAIR) – 75 TO 79% correct 3. (SATISFACTORY)– 80 to 84% correct 4. (VERY SATISFACTORY) – 85 to 89% correct 5. (OUTSTANDING)– 90 to 100% correct 178

General Biology 2

90 MINS

Lesson 19: Compare and Contrast Process in Plants and Animals: Gas Exchange Content Standard

The learners demonstrate an understanding of plant and animal organ systems for gas exchange and their functions. Performance Standards


enumerate the structures or organs involved in gas exchange in plants and animals;

•

trace the pathway of air in a mammalian respiratory system; and

•

explain the coordination of the respiratory system with the circulatory system in the transport of gases to the body tissues.

Learning Competency

The learners shall be able to compare and contrast gas exchange in plants and animals. STEM_BIO11/12-IVa-h-1 Specific Learning Outcomes


state some basic principles IN gas exchange;

•

describe the structures for gas exchange in plants and animals;

•

compare breathing mechanisms in vertebrates;

•

describe the organs in the human respiratory system and their roles;

•

discuss the coordination of gas exchange and circulation;

•

explain the control of respiration in vertebrates;

•

describe some respiratory adaptations to extreme conditions such as lowoxygen environments; and

•

cite some respiratory problems and impact on public health.

LESSON OUTLINE


5

Motivation

Questions on Gas Exchange

Instruction

Lecture on Gas Exchange

Practice

Cross-section of Species

40

Enrichment

Conceptual Questions

10

Evaluation

Assignment

10

5 100

Materials Microscopes and slides of monocot and dicot lead cross-section, leaf upper and lower epidermis, and insect tracheal system. In the absence of microscopes and slides, visual aids of the mentioned specimens may be used; visual aids on the human respiratory system; insect tracheal system; toad, dissecting pan, dissecting set, gloves.

Resources (1) Barrion AA, Tudor MFVA, Colle MCD, Reamillo MCS, and MAP Robles. 2000. BIOLOGY II Laboratory Manual: An Investigative Approach. Institute of Biological Sciences, College of Arts and Sciences, UP Los Baños. ISBN 971-547-099-8. 140p. (2) Brooker RJ, Widmaier EP, Graham LE, Stiling PD. 2008. Biology. Boston: McGraw- Hill. 1300 pp. (3) Johnson GB and PH Raven.1996. BIOLOGY: Principles and Explorations.Austin, USA: Holt, Rinehart and Winston. 1072p. (4) Reece JB, Urry LA, Wasserman SA, Minorsky PV, Jackson RB. 2011. Campbell Biology (10th Edition). US: Benjamin Cummings. 1488 pp. (5) Starr C and R Taggart. 2004. BIOLOGY: The Unity and Diversity of Life. Tenth Edition. Australia: Thomson – Brooks/Cole. 933p.


1. Present the topic outline for Gas Exchange: I. Basic principles influencing gas exchange II. Structures for gas exchange in plants and animals III. Breathing mechanisms in vertebrates IV. The Human respiratory system V. Coordination of gas exchange and circulation VI. Control of respiration in vertebrates VII. Respiratory adaptations to extreme conditions VIII.Respiratory problems and on public health 2. Cite the specific learning objectives for this topic.

MOTIVATION (10 MINS) Questions on Gas Exchange

1. Ask the students what else do organisms need to acquire from the environment aside from nutrition? Why? Suggested response: oxygen – needed for cellular respiration, in the process of extracting chemical energy from food (with the exception of anaerobic organisms) 2. What gas is considered a metabolic waste product of cellular metabolism? How does it leave the organism’s body? Suggested response: carbon dioxide – it diffuses out of the respiratory surface of the organism 3. Ask the students to cite the structures in plants and animals that allow for gas exchange. Suggested responses: please refer to respiratory structures cited in the lecture 4. Let the students enumerate some respiratory problems encountered by humans. Suggested responses: asthma, emphysema, lung cancer, pneumonia

180

INSTRUCTION (100 MINS) Lecture on Gas Exchange

1. Define gas exchange: I. Gas exchangeis the uptake of molecular oxygen from the environment and the discharge of carbon dioxide to the environment. or respirationbut it should not be confused with II. It is often called respiratory exchange cellular respiration. III. Oxygen is needed in tissues for aerobic cellular respiration to occur and extract ATP from food. IV. Carbon dioxidemust be released to prevent physiological pH in tissues from being very acidic. In plants however, the carbon dioxide that is released as a by-product of cellular respiration may again be taken up for the process of photosynthesis. 2. State some basic principles influencing gas exchange: I. The respiratory surface or organ is the part of an animal’s body where gases are exchanged with the environment. To allow for gas exchange, it must be moist, large enough, and protected from dessication. II. Respiratory systems rely on the diffusion of gases down pressure gradients. A. Partial pressures for each gas in the atmosphere can be computed; for example, the partial pressure of oxygen is 160 mm Hg. B. Fick’s Law states that the amount of diffusion of a gas across a membrane is proportional to the surface area and the difference in partial pressure between the two sides and inversely proportional to the thickness of the membrane. III. Surface-to-volume ratio A. As an animal grows, the surface area increases at a lesser rate than its volume, making diffusion of gases into the interior more difficult B. Animals must have a body design that keeps internal cells close to the surface (e.g. flatworms) or must have a system to move the gases inward. IV. Ventilation A. It refers to the movement of the respiratory medium (air or water) over the respiratory surface.

B. Bony fish moves the gill covers (operculum) for water carrying oxygen to flow across the gill. C. Humans move the muscles of the thorax to expand and contract the chest cavity and move air in and out of the lungs. V. Respiratory Pigments or Proteins A. Adaptations of animals for gas exchange include respiratory pigments that bind and transport gases. B. The respiratory pigment of vertebrates is hemoglobin while that of invertebrates (e.g. arthropods and molluscs) is hemocyanin. C. Blood cannot carry sufficient oxygen and carbon dioxide in dissolved form to meet the body’s requirements; hemoglobin helps enhance its capacity. 3. Describe structures for gas exchange in plants: I. Stomates in leaves

Figure of a leaf cross-section showing stomates.

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II. Lenticels in stems III. Root hairs in aerial roots IV. Pneumatophores or the lateral roots of mangroves 4. Describe respiratory surfaces or organs in invertebrates: I. Cell surface or cell membrane – especially used in unicellular organisms II. Integumentary exchange – refers to the general body surface or skin used by animals with high surface-to-volume ratio; e.g. flatworm and earthworm. Amphibians also use their skin in addition to lungs as gas exchange surface III. External Gills – used by invertebrates that live in aquatic habitats; gills are highly folded, thin- walled, vascularized epidermis that project outward from the body; e.g. crayfish, lobster, sea star, nudibranch IV. Tracheal system in arthropods – utilizes fine air-conducting tubules to provide gaseous exchange at the cellular level; it is not dependent on a circulatory system; e.g. insects, spiders 5. Describe respiratory surfaces in vertebrates: I. External Gills – thin, vascularized epidermis that project from the body surface of a few amphibians; e.g. larval salamander II. Internal Gills – rows of slits or pockets in adult fishes positioned at the back of the mouth such that water that enters the mouth can flow over them as it exits just behind the head. A. Water flows over the gills and blood circulates through them in OPPOSITE DIRECTIONS. B. This mechanism, called countercurrent flow, is highly efficient in extracting oxygen from water, whose oxygen content is lower than air. III. Lungs – internal respiratory surfaces shaped as a cavity or sac; lungs provide a membrane for gaseous exchange; since they are not in direct contact with all other parts of the body, lungs require a circulatory system to transport gases to the rest of the body; found in birds, reptiles, and mammals. A. Air moves by bulk flow into and out of the lung.

B. Gases diffuse across the inner respiratory surfaces of the lungs. C. Pulmonary circulation allows the diffusion of dissolved gases across lung capillaries D. In body tissues, oxygen diffuses from blood! interstitial fluid ! cells; the pathway of carbon dioxide is in reverse E. All lungs receive deoxygenated blood from the heart and return oxygenated blood to the heart.

Different respiratory surfaces or organs in animals: (a) cell surface or cell membrane; (b) integumentary exchange across body surface; (c) body surface with protruding papulae in echinoderms; (d) tracheal system in arthropods; (e) gills in fishes; and (f) alveoli in mammalian lungs. (Source: Raven and Johnson, 2001 PDF copy)

184

6. Compare breathing mechanisms in vertebrates: I. Amphibians ventilate their lungs by positive pressure breathingwhich forces air down the trachea. II. Birds use a system ofair sacsas blower to keep air flowing through the lungs in one direction only, preventing the mixing of incoming and outgoing air. III. Mammals ventilate their lungs by negative pressure breathingwhich pulls air into the lungs when the volume of the lungs expands as the rib muscles and diaphragm contract. However, the incoming and outgoing air mix, decreasing the efficiency of ventilation. 7. Describe the human respiratory system: I. Air enters or leaves the respiratory system through nasal cavities where air is filtered by hair and cilia, warmed by blood vessels, and moistened with mucus.

II. Carbon Dioxide Transport A. Carbon dioxide diffuses down its partial pressure gradient from the tissues into the blood plasma and red blood cells " air in alveoli. B. Seven percent is dissolved in plasma, 23% binds with hemoglobin to form carbaminohemoglobin, and 70% is in bicarbonate form. C. Bicarbonate and carbonic acid formation is enhanced by the enzyme carbonic anhydrase, which is located in the red blood cells. III. Coordination of air flow with blood flow: A. Gas exchange in the alveoli is most efficient when air flow equals the rate of blood flow. B. Local controls within the lungs correct imbalances in air and blood flow by constricting or dilating both bronchioles and arterioles.

8. Discuss the coordination of gas exchange and circulation: I. Oxygen Transport A. Oxygen diffuses down a pressure gradient from the lungs into the blood plasma " red blood cells " binds to hemoglobin (4 molecules per hemoglobin to form oxyhemoglobin). B. Hemoglobin gives up its oxygen in tissues where partial pressure of oxygen is low, blood is warmer, partial pressure of carbon dioxide is higher, and pH is lower; these four conditions occur in tissues with high metabolism.

9. Explain the control of respiration in vertebrates: I. The nervous system controls oxygen and carbon dioxide levels for the entire body by regulating the rate and depth of breathing. II. The brain monitors the pH of the cerebrospinal fluid through sensors (reflecting carbon dioxide concentration in the blood). III. Secondary control is exerted by sensors in the aorta and carotid arteries that monitor blood levels of oxygen as well as carbon dioxide (via blood pH).

10. Describe some respiratory adaptations to extreme conditions such as low-oxygen environments:

PRACTICE (40 MINS) Cross Section of Species

I. Animals that inhabit high altitudes have larger hearts and lungs, and hemoglobin with a high affinity for binding oxygen.

1. As an alternative to a pure lecture discussion, questions related to the different structures for gas exchange in plants and animals may be asked. As each respiratory structure is discussed, reference to an overhead transparency or visual is suggested.

II. Many diving animals have unusually high hematocrits (ratio of the volume of packed red blood cells to the volume of whole blood) and also muscles with high amounts of myoglobin (an oxygen-binding protein found in muscle cells)

2. Ask the students to observe and draw the following either from a microscopic examination or through the use of visual aids: (a) monocot leaf cross section e.g.Zea mays; (b) dicot leaf cross section e.g. Ixora sp. Label the upper and lower epidermis, mesophyll, and vascular bundles.

11. Cite some respiratory problems and impact on public health: I. In a respiratory disorder like asthma, the muscles around bronchioles contract more than usual, increasing resistance to airflow.

3. Describe how air can enter the leaf. If the following are available (microscopes, slides, coverslips, scalpel or blade), prepare thin sections of the upper and lower epidermal surfaces of Rhoeo spathacea. Examine the stomata under the microscope for both the upper and lower epidermis. Which side contains more stomates? Draw the leaf epidermis showing the stoma. Label the stomatal pore, guard cells, and subsidiary or accessory cells.

II. Emphysema is an abnormal condition of the lungs marked by decreased respiratory function; associated with smoking or chronic bronchitis or old age. III. Smoking tobacco products is one of the leading global causes of death and is strongly linked to cancer, cardiovascular disease, stroke, and emphysema.

4. Draw an insect tracheal system from a visual aid. The large tracheae are reinforced by thickened spiral rings of cuticle called taenidia while the smaller tracheae have annular rings. Label the large tracheae, taenidia, smaller tracheae, and annular rings. As an alternative, dissect a cockroach and locate the tracheal system. Under the dissecting microscope, these appear as silvery white tubes throughout the insect’s body.

IV. Pneumonia is an infectious disease involving inflammation and fluid buildup in the lungs.

5. Pith and dissect a toad. Examine the external nares and the oral cavity. Locate the epiglottis which leads to the glottis. Observe the lungs in the chest cavity. What do you call the numerous branches and the air sacs found in the lungs? Draw a diagrammatic representation of the respiratory system of the toad. Label the external nares, pharynx, epiglottis, glottis, larynx, trachea, bronchi, and lungs. 186


Teacher Tip:


1. Why is the position of lung tissues within the body an advantage for terrestrial animals? 2. After a heavy rain, earthworms come to the surface. How would you explain this behavior in terms of an earthworm’s requirements for gas exchange? 3. How does an increase in the carbon dioxide concentration in the blood affect the pH of the cerebrospinal fluid?

Answer to Question 3: An increase in blood carbon dioxide concentration causes an increase in the rate of carbon dioxide diffusion into the cerebrospinal fluid, where the carbon dioxide combines with water to form carbonic acid. Dissociation of carbonic acid releases hydrogen ions, decreasing the pH of the cerebrospinal fluid (Reece et al., 2011).


1. Which of the following is not a structure for gas exchange in plants? A. Stomates B. Lenticels C. Aerial root hairs D. Flowers E. Pneumatophores 2. Which of the following respiratory systems is not closely associated with a blood supply? A. The lungs of a vertebrate B. The tracheal system of an insect C. The gills of a fish D. The skin of an earthworm C. When you hold your breath, which of the following gas changes in the blood first leads to the urge to breathe? A. Rising oxygen B. Falling oxygen C. Rising carbon dioxide D. Falling carbon dioxide E. Rising carbon dioxide and falling oxygen

4. The driving force for diffusion of oxygen across the cells of a respiratory organ is: A. The difference in partial pressure of oxygen in the environment and in the blood. B. The humidity. C. The partial pressure of carbon dioxide in the blood. D. The temperature. E. All of the above. 5. The process of bringing oxygenated water or air into contact with a gas-exchange surface is: A. Respiration B. Ventilation C. Inspiration D. Resuscitation E. Exhalation

6. The group of vertebrates that relies on gas exchange across the skin as well as at the lungs to maintain sufficient blood oxygen levels is: A. The fishes B. The reptiles C. The amphibians D. The birds E. The mammals

8. Which of the following factors does not alter the rate of breathing by influencing the respiratory centers of the brain? A. Carbon dioxide partial pressures in the blood B. Oxygen partial pressures in the blood C. Blood pH D. Blood glucose levels E. Hydrogen ion concentration in the blood 9. With rare exceptions, the majority of oxygen is transported in the blood of vertebrates A. By binding to plasma proteins B. By binding to hemoglobin in erythrocytes C. As a component of large organic molecules that are broken down by the cells D. As dissolved gas in the cytoplasm of erythrocytes E. By binding to myoglobin

7. In negative pressure filling, air moves into the lungs when A. The volume of the thoracic cavity increases B. The pressure in the thoracic cavity decreases C. Air is forced down the trachea by muscular contractions of the mouth and pharynx D. All of the above E. A and B only

10. Which of the following is brought about by infection and involves inflammation and fluid buildup in the lungs? A. Emphysema B. Pneumonia C. Asthma D. Coughing E. Sneezing

ANSWER KEY

1. D. 2. B.

6. C. 7. E.

3. C. 4. A.

8. D. 9. B.

5. B.

10. B.

ASSIGNMENT

Teacher Tip:

1. Explain the underlying mechanism in the opening and closing of a stomate.

Answers to the assignment may be written on bond paper and submitted on the following meeting.

2. How does oxygen get to the different parts of the plant? 3. Explain countercurrent flow. How does it help make the fish gill the most efficient respiratory organ?

Answers to the assignment may be found in Reece et al., 2011; Starr and Taggart, 2004, and; any General Biology book.

188

4. Compare the avian and mammalian lungs in terms of structure and respiratory function. 5. Discuss the special adaptations for life at high altitudes. 6. In what form does most of the carbon dioxide travel in the blood? How and where is this molecule produced? 7. How does the brain control inspiration and expiration? How do peripheral and central chemoreceptors influence the brain’s control of breathing? 8. What respiratory problems can arise from habitual smoking? Explain how these problems may develop due to smoking.

ASSESSMENT GUIDE (FOR THE ACTIVITY AND LABORATORY WORK NUMBERS 2 AND 3 INVOLVING DRAWING LABELING)

1. (POOR) – disorganized drawing with many errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 2. (SATISFACTORY)– acceptable drawing with some errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 3. (VERY GOOD)– clear drawing with minimal error in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 4. (EXCELLENT)– clear drawing with correct labels for the cell layers in the root cross sections; and accurate tracing of the apoplast and symplast routes.

ASSESSMENT GUIDE (FOR QUIZ AND ASSIGNMENT): THE TEACHER MAY ASSIGN POINTS TO THE QUESTIONS

1. (POOR) – 74% and below 2. (FAIR) – 75 TO 79% correct 3. (SATISFACTORY)– 80 to 84% correct – 85 to 89% correct 4. (VERY SATISFACTORY) 5. (OUTSTANDING)– 90 to 100% correct

General Biology 2

60 MINS

Lesson 20: Compare and Contrast Process in Plants and Animals: Transport and Circulation LESSON OUTLINE


Content Standard

The learners demonstrate an understanding of plant transport and animal circulation

10

Motivation

Demonstration

10

Instruction

Discussion of Plant Transport and Animal Circulation

90

Practice Evaluation

Experiment Quiz

20 30

Enrichment

Video and Take-Home Research

10



state the functions of various structures involved in plant transport and animal circulation.

Learning Competency

The learners compare and contrast transport and circulation in plants and animals (STEM_BIO11/12-IVa-h-1 )

Materials


Resources


describe the transport of substances in xylem and phloem;

•

explain the functions of structures in animal circulation; and

•

trace the path of blood in the systemic and the pulmonary circulation

190

Podcast, Pig’s Heart, Models of the Heart

(1) Human Anatomy and Physiology: http://www.internet4classrooms.com/ high_school/human_anatomy_physiology_transport.htm (Retrieved 09/08/15) (2) The Transport System: http://www.ib.bioninja.com.au/standard-level/ topic-6-human-health-and/62-the-transport-system.html (Retrieved 09/08/15) (3) Circulatory System: Facts, Function and Diseases- http:// www.livescience.com/22486-circulatory-system.html (4) The Circulatory System: https://www.youtube.com/watch? v=NJzJKvkWWDc (5) Crash Course- Circulatory and Respiratory Systems: https:// www.youtube.com/watch?v=9fxm85Fy4sQ (6) Inner Body: The Heart- http://www.innerbody.com/image/card01.html

INTRODUCTION (10 MINS) 1. The learning objectives will be communicated to the class. 2. Tell the class that transport in animals is basically due to the circulatory system. A cardiovascular system consists of the heart, blood and blood vessels. The heart pumps the blood which circulates to other body parts through blood vessels. Along the way, nutrients and other substances are delivered to body tissues and wastes are removed to be excreted out from the body.

Teacher Tip:

MOTIVATION (10 MINS) 1. Show the class a cut celery stick. The big holes they see are huge xylem cells. Describe the importance of transport in organisms. 2. Show a model of the human heart. Ask learners the function of the heart in transport. Ask learners if they remember/ know any parts of an animal’s heart.

Teacher Tip:

INSTRUCTION (90 MINS) Plant Transport

1. Ask the learners to recall the functions of xylem and phloem from BIO 1. The current topic is mentioned in the chapter on Nutrient procurement but it may also be reviewed here. Plant transport involves: (A) absorption of water through the roots and (B) up and down movement of substances in phloem. A. Absorption of water plus macronutrients and micronutrients through the root system is possible by diffusion. Root hairs increase the surface area for transport. Water molecules pass through the epidermis, cortex, endodermis and pericycle; then they move upwards by means of xylem vessels. B. Phloem cells transport substances such as products of photosynthesis, water and other compounds up and down the plant body. Phloem tissues are adjacent to companion cells that give them support and nourishment. There are two major hypotheses on how substances can move up and down the plant body. These are (i) Ascent of xylem sap and (ii) Pressure flow or bulk flow. i.

Ascent of xylem sap is explained as a “push” from below by the water molecules gushing upwards through xylem vessels. It can also be described as “pull” from above by a combination of transpiration (evaporation of water from

“Transport” and “Circulation” are interchangeable terms although the term “transport” usually applies to structures that deliver water and substances throughout the plant body. “Circulation” as a term is more applicable to animals.

The heart is the pump that pushes blood to the lungs for oxygenation and delivers it to different body parts. It consists of several chambers, muscles and are connected with blood vessels.

the plant body) and cohesion of water molecules through hydrogen bonds. ii. Pressure flow or bulk flow maintains that in the plant there is a source cell and a sink cell. A “source” cell is where photosynthesis occurs and a “sink” cell is where the nutrients are needed. Leaf cells are definitely source cells. Sucrose and other substances accumulate in the source and due to high concentration they flow down (or up) where they are needed. Sink cells are growing parts of the plants- buds, flowers, fruits, root tips. In this way, phloem tissues carry materials down and up. Xylem lies adjacent to phloem tissues and water may easily diffuse from xylem to phloem. Materials are transported up and down the plant body by a combination of the actions of phloem and xylem cells. Animal Circulation

1. With visual aids make a lecture on animal circulatory systems. Discuss the “evolution” of the heart in vertebrates. Fish have one atrium and one ventricle. Amphibians have two atria and one common ventricle where oxygenated and deoxygenated blood mix. In mammals and birds there is a complete separation of the four chambers of the heart by a tissue, called the septum. 2. Trace the path of blood in Systemic and Pulmonary Circulation. Mention the major arteries, veins and heart chambers where blood flows through. Show the class the major valves between the heart chambers.

PRACTICE (20 MINS) 1. If available, dissect a pig’s heart. Show the major chambers and valves of the heart. EVALUATION (10 MINS) 1. A short quiz may be given to compare and contrast plant and animal transport mechanisms. 2. The path of blood in systemic versus pulmonary circulation may be followed through a diagram.

192

Teacher Tip: Be guided by an atlas of heart anatomy.

ASSIGNMENT

Teacher Tip:

1. Research on the following technologies related to the circulatory system. A. Pacemaker B. Electrocardiograph (ECG) C. Stethoscope D. Defibrillator E. Sphygmomanometer F. Computerized axial tomography (CAT) G. Magnetic resonance imaging (MRI)

Topics can be assigned to volunteer pairs/ groups. One pair/ group will discuss the technologies and another group will discuss the diseases. If many pairs/ groups volunteer to report, they will draw lots to determine who will report. Other groups will be given a chance to report in future topics. The rest of the class will evaluate the group report based on the following: A. Content B. Creativity C. Delivery

2. Research on the following diseases of the circulatory system. A. Hypertension B. Aneurysm C. Rheumatic heart disease D. Stroke E. F. G. H. I.

Leukemia Sickle-cell anemia Atherosclerosis Thrombosis Hemophilia

ENRICHMENT (30 MINS) 1. Watch a video on animal circulation. Use the following guide questions: I. How do animals transport materials inside their bodies? II. What structures are necessary in animal transport? III. State the function of the following components of animal transport: heart, blood and blood vessels. 2. You may put on the board cut-outs/ drawings of the parts of the circulatory system. Call on learners to go the board, get a part then describe the main features and functions of the part.

General Biology 2

60 MINS

Lesson 21: Compare and Contrast Process in Plants and Animals: Regulation of Body Fluids LESSON OUTLINE

Content Standard


The learners demonstrate an understanding of animal organ systems for regulation of body fluids and their functions. Performance Standards


Questions related to Body Fluids

Instruction

Lecture on Body Fluids

Practice

Analogy

40

Conceptual Questions Assignment

20 10

•

enumerate the structures or organs involved in regulation of body fluids in

•

animals; describe the different parts of the mammalian urinary system and their functions;

Enrichment Evaluation

•

discuss the role of nephrons as the functional units of the kidney; and

•

explain the regulation of mammalian kidney function.

Visual aids or models or models of excretory systems in invertebrates; visual aids on the human urinary system, kidney, and nephron; toad, dissecting pan, dissecting set, gloves.

Learning Competency

The learners shall be able to describe excretory systems in animals especially the human urinary system and their functions in homeostasis. (STEM_BIO11/12-IVa-h-1) Specific Learning Outcomes


define some key terms related to osmoregulation;

•

describe different types of animals based on the osmolarity of their body fluids in relation to the environment;

•

enumerate the three types of nitrogenous wastes in animals;

•

enumerate and describe excretory systems in invertebrates;

5

Motivation

3 100

Materials

Resources (1) Barrion AA, Tudor MFVA, Colle MCD, Reamillo MCS, and MAP Robles. 2000. BIOLOGY II Laboratory Manual: An Investigative Approach. Institute of Biological Sciences, College of Arts and Sciences, UP Los Baños. ISBN 971-547-099-8. 140p. (2) Brooker RJ, Widmaier EP, Graham LE, Stiling PD. 2008. Biology. Boston: McGraw- Hill. 1300p. (3) Hoefnagels M. 2013. Biology: The Essentials. New York: McGraw-Hill. 631p. (4) Johnson GB and PH Raven.1996. BIOLOGY: Principles and Explorations.Austin, USA: Holt, Rinehart and Winston. 1072p. (5) Reece JB, Urry LA, Wasserman SA, Minorsky PV, Jackson RB. 2011. Campbell Biology (10th Edition). US: Benjamin Cummings. 1488p. (6) Starr C and R Taggart. 2004. BIOLOGY: The Unity and Diversity of Life.

194

Tenth Edition. Australia: Thomson – Brooks/Cole. 933p.

•

characterize the mammalian urinary system and the role of nephrons; and

•

analyze the role of the kidneys in the body’s acid-base balance.


1. Present the topic outline for Gas Exchange: I. Some key terms related to osmoregulation II. Different types of animals based on the osmolarity of their body fluids in relation to the environment III. Three types of nitrogenous wastes in animals IV. Excretory systems in invertebrates V. The mammalian urinary system and the role of nephrons VI. The mechanism of urine formation VII. The regulation of mammalian kidney function VIII.The role of the kidneys in the body’s acid-base balance 2. Cite the Specific Learning Outcomes for this topic.

MOTIVATION (3 MINS) Questions related to Body Fluids

1. Ask the learners the possible consequences should there be a failure in the ability of the body to dispose or eliminate toxic metabolic wastes.

INSTRUCTION (30 MINS) Lecture on Body Fluids

1. Define some key terms related to the regulation of body fluids: – the fluid environment that bathes the cells (extracellular fluid) I. Internal environment composed of the interstitial fluid and blood. II. Osmolarity– solute concentration expressed in milliosmoles per liter of solution (mOsm/L).

Teacher Tip The presentation of the topic on Regulation of Body Fluids can be divided i nto a two- hour lecture and one-hour laboratory/ activity work.

III. Osmosis– the movement of water from a region of higher osmolarity to a region of lower osmolarity across a selectively permeable membrane. IV. Osmoregulation– the regulation of water and ion balance. V. Excretion– the elimination of metabolic wastes including nitrogenous wastes produced from the breakdown of proteins; this process also helps in the regulation of water and ion balance. 2. Describe the two types of animals based on the osmolarity of their body fluids in relation to the environment: I. Osmoconformers– allow the osmolarity of their body fluids to match that of the environment; A. These include most marine invertebrates with body fluids that are generally hyperosmotic to their surroundings B. Because their bodies are isosmotic to seawater, they consume little or no energy in maintaining water balance II. Osmoregulators – keep the osmolarity of body fluids different from that of the environment; A. These include most marine vertebrates, birds, mammals B. Either they discharge water in hypotonic environment or they take in water in a hypertonic environment 3. Identify the three types of nitrogenous wastes excreted by animals: I. Ammonia– the primary nitrogenous waste for aquatic invertebrates, teleosts, and larval amphibians A. It is readily soluble in water but is also highly toxic B. It can be excreted from the body only in dilute solutions. II. Urea – produced by mammals, most amphibians, some reptiles, some marine fishes, and some terrestrial invertebrates A. It is formed by combining ammonia with bicarbonate ion (HCO3 )" and converting the product into urea B. Although its formation requires more energy compared to ammonia, it is about 100,000x less toxic than ammonia C. Its excretion requires only about 10% as much water compared to ammonia 196

Teacher Tips: The lecture presentation may be divided into two one-hour sessions and a one-hour session can be allotted for activity: 1ST HOUR: A. Some key terms related to omoregulation B. Different types of animals based on the osmolarity of their body fluids in relation to the environment C. Three types of nitrogenous wastes in animals D. Excretory systems in invertebrates 2ND HOUR: E. The mammalian urinary system and the role of nephrons F. The mechanism of urine formation G. The regulation of mammalian kidney function H. The role of the kidneys in the body’s acid-base balance 3RD HOUR: Laboratory Activities

III. Uric acid– excreted by birds, insects, and terrestrial reptiles A. It is relatively nontoxic but more energetically expensive to produce than urea B. It is largely insoluble in water and it is excreted as a semisolid paste or precipitate with very little water loss 4. Enumerate and describe excretory systems in invertebrates: – allows passage of wastes in unicellular organisms I. Cell surface or cell membrane – a specialized cytoplasmic organelle in many freshwater protists (e.g. II. Contractile vacuole Paramecium) that expels excess water out of the cell to prevent lysis – network of tubules that lack internal openings III. Protonephridia or Flame Bulb System but have external openings at the body surface called nephridiopores such as in the flatworm, Dugesia. A. The smallest branches of the tubule network end with a large cell called a flame bulb or cell B. Water and solutes in body fluids enter the flame cell and get filtered C. Specific molecules and ions are removed by reabsorption while other ions and nitrogenous wastes are released into the tubule network and excreted via the nephridiopore. IV. Metanephridia– the excretory tubule of most annelids and adult mollusks; A. The tubular network has a funnel-like internal opening called a nephrostome that collects body fluids B. As the body fluids move through the network, some molecules and ions are reabsorbed while other ions and nitrogenous wastes are secreted into the tubule C. The bladder stores the nitrogenous wastes as urine and later on excreted from the body surface via the nephridiopore – the excretory tubules of insects and other terrestrial arthropods V. Malpighian Tubules attached to their digestive tract (midgut); A. The tubules have ends that are immersed in the hemolymph (circulatory fluid) while the distal ends empty into the gut B. Malpighian tubules do not filter body fluids; instead they employ secretion to generate the fluid for release from the body C. In particular, they help actively secrete uric acid and ions like Na+ and K+ into the tubules, allowing the water to move osmotically from the hemolymph into the tubule

Teacher Tips: This part of the lecture can be supplemented with visual aids of the different excretory system to be discussed.

D. E.

The

fluid then passes into the hindgut (intestine and rectum) of the insect as dilute urine of ions and water occurs in the hindgut wall, causing the formation of uric acid crystals that are released with the feces.

Reabsorption

5. Characterize the mammalian urinary or excretory system: I. The mammalian urinary system consists of two kidneys, each with a ureter, a tube leading to a urinary bladder(for storage), with an open channel called urethraleading to the body surface.

6. Describe the components of nephrons – functional units of kidneys: I.

II. The kidneys serve as specialized organs for osmoregulation and excretion; they are composed of the following:

Nephronsgenerally have the following components:

– an infolded region that encloses a A. Bowman’s capsule ball of blood capillaries called glomerulus where initial filtration of the blood plasma occurs.

A. Renal capsule– the outer coat of connective tissue; B. Cortex – the zone near the capsule consisting of blood vessels and nephrons;

B. Renal tubules– receive and modify the glomerular filtrate; consist of a proximal convoluted tubule, followed by a U-shaped loop of Henle, and a distal convoluted tubule.

C. Medulla– inner zone also consisting of blood vessels and nephrons;

– bring substances to and take C. Peritubular capillaries substances away from the renal tubules.

D. Nephrons– the functional units of the kidney where urine is formed; and

D. Collecting duct– receives the urine from the renal tubule leading to the renal pelvis.

E. Renal pelvis– central cavity in the kidney where urine coming from the nephrons is channeled before going to the ureter.

II. Nephrons filter and retain water and solutes, leaving concentrated urine to be collected in the central renal pelvis.

III. Each kidney contains about 1.3 M nephrons, approximately 80 km long if connected end to end.

III. The glomerulus serve as initial site for filtration and the glomerular filtrate produced is directed into the Bowman’s capsule.

IV. About 1,600 liters of blood pass through the kidneys each day (300x the blood volume); approximately 180 liters become filtrate but only about 1.5 liters of urine get excreted.

IV. The Bowman’s capsule collects the filtrate and directs it though the continuous renal tubules: proximal tubule " loop of Henle " distal tubule " collecting duct " renal pelvis.

V. More than 99% of the water and almost all sugar, vitamins and other organic nutrients are reabsorbed across the tubule epithelium.

V. The peritubular capillaries exit the glomerulus, converge, then branch again around the nephron tubules where they 198

participate in reclaiming water and essential solutes.

ii. Filtrate is collected by the Bowman’s capsule and funneled into the proximal tubule. B. During tubular reabsorptio, nuseful materials such as salts, water, glucose, and amino acids move out from the renal tubules and into adjacent peritubular capillaries. results in movement of surplus C. Tubular secretion hydrogen and potassium ions, uric acid, toxins and other drugs from the blood into the renal tubules. II. There are several factors influencing filtration: A. Blood enters the glomerulus under high pressure in order to facilitate filtration; arterioles present in the glomerulus tend to have wider diameters than most. B. Glomerular capillaries are highly “leaky” to water and small solutes. C. The volume of blood flow affects the rate of filtration.

Figure 1. The organization of the mammalian nephron – the functional unit of the kidney. (Picture taken from Reece et al., 2011.) 7. Discuss the mechanism of urine formation in mammalian nephrons: I. Urine formation involves three processes: A. In filtration, blood pressure forces filtrate (water and small solutes) out of the glomerular capillaries. i.

Blood cells, proteins, and other large solutes cannot pass the capillary wall and they remain in the blood.

8. Discuss the regulation of mammalian kidney function: I. Receptors in the juxtaglomerular apparatus function in the kidney’s autoregulation system. A. The receptors trigger constriction or dilation of the afferent arteriole to keep blood flow and filtration constant during small variations in blood pressure. II. Antidiuretic hormone (ADH) promotes water conservation. A. It is secreted from the hypothalamus via the pituitary when osmoreceptors detect an increase in the osmolarity of body fluids. B. It makes the walls of distal tubules and collecting ducts more permeable to water, and thus the urine becomes more concentrated.

III. Aldosterone enhances sodium reabsorption. A. When too much sodium is lost, extracellular fluid volume is reduced, and pressure receptors detect corresponding drop in blood pressure. B. In response, the kidney secretes an enzyme, renin, which indirectly stimulates the adrenal cortex to secrete aldosterone, which in turn stimulates reabsorption in the distal tubule and collecting ducts. IV. Cells in the hypothalamus thirst center inhibit saliva production and stimulate the urge to drink when there is an increase in the solute concentration in extracellular fluid. 9. Explain the role of the kidneys in the body’s acid-base balance: I. Over-all acid-base balance is maintained by controlling hydrogen ions through buffer systems, respiration, and excretion by the kidneys. II. Only the urinary system can eliminate excess hydrogen ions, permanently, and restore the bicarbonate buffering ions to the blood.

PRACTICE (40 MINS) Analogy

1. As a supplement to the lecture discussion, the teacher may ask the learners to make an analogy to the functions of the different parts of:

5. Provide visual aids of the following excretory organs and allow the learners to draw them in their worksheets with proper labeling of parts:

I. urinary system II. kidney

I.

Cell membrane

II. Contractile vacuole III. Protonephridia

III. nephron 2. Use a mannequin or a visual aid to show the locations of urinary organs.

IV. Metanephridia V. Malpighian tubules

3. Exhibit a model of a kidney to illustrate its parts and the blood vessels associated with it.

6. Actual dissection of toad can also be done in order to observe the following parts: I. Kidney II. Ureter III. Bladder

4. Display a model of a nephron and review the process of urine formation. 200

ENRICHMENT (10 MINS) Conceptual Questions

1. Of the three processes – filtration, reabsorption, secretion – which is (are) accomplished by a kidney dialysis machine? Explain any limitations of the device. 2. Why do high-protein diet supplements for increasing muscle mass or losing weight include warnings stating that water intake must be increased when consuming the product? 3. Why does eating salty foods make you thirsty? Why does eating salty foods make you temporarily gain weight? Quiz

1. Which process is primarily involved in the control and maintenance of water and ion balance in the body?

3. The following are true about uric acid as a form of nitrogenous waste except:

A. Respiration B. Osmoregulation

A. Excreted by birds and insects B. Relatively non-toxic

C. Excretion D. Nutrition

C. Highly soluble in water D. Energetically expensive to produce from ammonia

E. Circulation

E. Excreted as a semi-solid paste

2. Which type of animals consume little or no energy in maintaining water balance? A. Birds B. Mammals

4. For numbers 4-6, match the type of excretory system with the corresponding animal where each is found: 4.Protonephridia

A.Cockroach

C. Marine vertebrates D. Marine invertebrates

5.Metanephridia

B.Flatworm

E. All of the above

6. Malpighian tubules

C. Earthworm

7. The part of the urinary system that serves to temporarily store urine:

9. The following components in the filtrate are reabsorbed back into the blood except:

A. Urinary bladder B. Kidneys

A. Water B. Glucose

C. Ureter D. Urethra

C. Amino acids D. Urea

E. Nephron

E. Salts

8. In each nephron of the kidney, the glomerulus and Bowman’s capsule:

10. The following are involved in the regulation of mammalian kidney function except:

A. Filter the blood and capture the filtrate. B. Reabsorb water into the blood.

A. ADH B. Aldosterone

C. Reabsorb salts and nutrients. D. Break down harmful toxins and poisons.

C. Renin D. Thirst center in hypothalamus

E. Refine and concentrate the urine for excretion.

E. Oxygen

ASSIGNMENT

ANSWER KEY:

1. List the organs that make up the human urinary system. What is the function of each?

1. B.

6. A.

2. Discuss in detail how the reabsorption and secretion of substances occur across the different parts of the renal tubules.

2. D.

7. A.

3. C.

8. A.

3. Kidney stones are calcium-rich crystals that form inside the kidney. What symptoms would you expect if the stones lodge in a ureter?

4. B.

9. D.

5. C.

10.E.

4. Shortly after you drink a large glass of water, you will feel the urge to urinate. Explain this observation. Begin by tracing the path of water, starting at the stomach and ending with the arrival of urine in the bladder. 5. Why is protein in the urine a sign of kidney damage? What structures in the kidney are probably affected? 202

Teacher Tip: Answers to the assignment may be written on bond paper and submitted on the following meeting.

ASSESSMENT GUIDE (FOR THE ACTIVITY AND LABORATORY

ASSESSMENT GUIDE (FOR QUIZ AND ASSIGNMENT): THE

WORK NUMBERS 2 AND 3 INVOLVING DRAWING LABELLING)

TEACHER MAY ASSIGN POINTS TO THE QUESTIONS

1. (POOR) – disorganized drawing with many errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes.

1. (POOR) – 74% and below

2. (SATISFACTORY)– acceptable drawing with some errors in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes.

2. (FAIR) – 75 TO 79% correct 3. (SATISFACTORY)– 80 to 84% correct – 85 to 89% correct 4. (VERY SATISFACTORY)

3. (VERY GOOD)– clear drawing with minimal error in the labeling of cell layers in the root cross sections and in the tracing of the apoplast and symplast routes. 4. (EXCELLENT)– clear drawing with correct labels for the cell layers in the root cross sections; and accurate tracing of the apoplast and symplast routes.

5. (OUTSTANDING)– 90 to 100% correct

General Biology 2

60 MINS

Lesson 22.1: Compare and Contrast Process in Plants and Animals: Immune Systems (1 of 3) Content Standard

The learners demonstrate an understanding of animal immune systems .

LESSON OUTLINE




5

Motivation

Inquiry

Instruction

Discussion of Innate and Adaptive Immune Systems

The learners shall be able to explain how immune systems work

Enrichment

Description of Inflammation

5

(STEM_BIO11/12-IVa-h-1)

Evaluation

Quiz

5


Materials

•

develop presentationthrough (e.g. play, to system. show how an organism maintainsahomeostasis the song) immune

Learning Competency


5 40

Freely downloadable images of disease symptoms and short videos of the innate and adaptive immune responses

•

compare innate and adaptive immune responses;

•

describe how the innate immune response helps protect a person from illness; and

•

explain why the innate immune response (inflammation in particular) is essential for a protective immune response.

204

Resources (1) Immunology textbooks (e.g., Coico, Richard and Geoffrey Sunshine. Immunology: A Short Course (Coico, Immunology) 7th Edition. 2015. WileyBlackwell)

INTRODUCTION (5 MINS) Communicate the learning objectives as follows:

I. compare innate and adaptive immune responses II. describe how the innate immune response helps protect a person from illness 2. Tell the learners that the lesson today will be on how the body protects itself from diseasecausing organisms.

Teacher Tips: 1. Ask the learners about the most common diseases that they have had. (Examples: common colds, diarrhea, influenza, dengue fever, etc.). 2. Ask the learners if they know or have heard of the following diseases: chikungunya; smallpox; leukemia

3. The teacher will ask volunteers to describe what is “Immunity”.

MOTIVATION (5 MINS) 1. Ask learners to think about what happens to them when they get sick. Ask them if they know the cause of these diseases: common colds (rhinoviruses); diarrhea (various bacterial toxins); influenza (influenza virus).

Teacher Tips: 1. Explain that persons usually get fevers or body pain no matter what kind of pathogen infects them. 2. Point out that it usually takes 3-4 days for them to get well. 3. The things mentioned areitdi rectly due two to the immune system above and how responds to pathogens.

INSTRUCTION (40 MINS) 1. Discuss the two types of immune system: innate and adaptive 2. Use a table to define and show the main differences between the innate and adaptive response (innate: fast-acting, non-specific; adaptive: slower response, pathogen-specific; etc.) 3. Explain that the innate immune response involves : I. Barrier defenses like the skin, mucous membranes and secretions. In humans and in most vertebrates, the skin with other ectodermal derivatives is the first line of defense against infection. Ask the class to recall their previous lessons on healthcare in their lower year levels; that is why it is important to wash hands with soap and water frequently. If there is an invading pathogen like a virus (or bacteria or any foreign substance) the body reacts through mucous secretions. Even the saliva contains agents which are antimicrobial. II. Internal defenses of the innate immune response consist of phagocytic cells, natural killer cells, antimicrobial proteins (interferons; the complement system) and the inflammatory response (that involves histamines, mast cells and cytokines).

Teacher Tips: Important points are 1. The innate immune response is always the first response to an infection. 2. The innate immune response acts fast, but never changes from exposure to exposure. 3. Inflammation is characterized by fever, redness, swelling, pain, and loss of function in the infected area. 4. Inflammation can help kill the pathogen (fever produces heat that may kill the bacteria/ viruses or make them stop replicating for example).

4. Explain that the adaptive immune response ( for vertebrates only ) involves the recognition of traits specific to particular pathogens using a vast array of receptors. The adaptive immune response is made possible because of: I. The Humoral response- production and secretion of antibodies or immunoglobulins against specific antigens (any foreign body/structure- pollen, bacteria, virus, dust). Antibodies are produced by cells that secrete them in the bloodstream or display them in the surface of some cells, ready to face and combat any antigen. II. Cell mediated response- occurs when cytotoxic cells defend the body against infection. The development of B and T cells, memory cells and plasma cells are important aspects of cell mediated immune mechanism. 5. As a practical lesson, describe inflammation and point out that is important in activating the adaptive immune response (acts as danger signals for the body)

ENRICHMENT (5 MINS) 1. Ask learners to describe when inflammation is good and when it is bad.

EVALUATION (5 MINS) 1. Which of the following is NOT a pattern found on pathogens that the immune system recognizes as foreign? A. Double stranded RNA B. Presence of N-formyl methionine

Teacher Tips: 4. Without the innate immune response, the adaptive immune response cannot be activated, because the innate immune response gives the rest of the immune system signals that say there is a real threat to the body that must be eliminated. 5. Therefore, stopping inflammation is not always a good thing. For example, you need to have a fever to really mount a full-blown response against a pathogen so taking paracetamol when you have a mild fever (below 38.3 OC) for example, may not always be a good thing since you may lose the sterilizing effects of the fever and dampen the danger signals that activate the adaptive immune response. However, it is still best to get medical advice on how to treat disease

Teacher Tip: Acute inflammation can be good since it activates the immune response, but chronic inflammation (e.g., arthritis, psoriasis, irritable bowel disease) is bad because it ultimately leads to tissue damage.

Correct answers: 1. 2. 3.

C. Presence of lipopolysaccharide (LPS) D. Double stranded DNA E. None of the above 2. What are the five hallmarks of inflammation? 3. What is the importance of inflammation in the immun e response

206

D. Double stranded DNA is normally found in human cells. Fever, redness, swelling, p ain, and loss of function. Inflammation is a signal produced by the body in response to a real infection. It also sends signals to the adaptive immune response that there is a real danger present and that it has to be eliminated.

General Biology 2

60 MINS

Lesson 22.2: Compare and Contrast Process in Plants and Animals: Immune Systems (2 of 3) LESSON OUTLINE

Content Standard

The learners demonstrate an understanding of the humoral immune response Performance Standard


2

Motivation

Antibodies and Antigens

Instruction

Humeral and Cellular Response

Learning Competency

Practice

Questions

5

The learners will be able to describe how immune systems contribute to homeostasis.(STEM_BIO11/12-IVa-h-1)

Enrichment

Inquiry on Vaccinations

5

Evaluation

Comic Strip

5


make a comic strip on the humoral immune response



define the term “antibody”;

•

name the different kinds of antibodies produced by humans; and

•

explain the function of each type of antibody.

3 40

Materials Freely downloadable images of antibodies and antigens. Freely downloadable molecular viewers (e.g. Swiss PDB Viewer; spdbv.org). Downloadable molecular models of antibodies from the Protein Data Bank (www.pdb.org; PDBID: 1H0D). Art supplies for creating comic strips, paper / clay models of antigen and antibody interactions.

Resources (1) Immunology textbooks (e.g., Coico, Richard and Geoffrey Sunshine. Immunology: A Short Course (Coico, Immunology) 7th Edition. 2015. Wiley-Blackwell)

Teacher Tips:


Pre-class discussion: “In the previous lecture, we learned that it takes about 4 days to fully activate our adaptive immune response.”


1. State the learning objectives as follows: I. define the term “antibody”; II. name the different kinds of antibodies produced by humans and

Can you explain what happens during those 4 days?

III. explain the function of each type of antibody 2. Mention that in the past lesson the innate immune response was described. It is necessary to activate the adaptive immune response. It should take about 3-4 days for a person to “get better” from an illness, meaning fever and other symptoms of inflammation should disappear after 3-4 days. 3. Point out that at day 3-4 of infection, the adaptive immune response is fully activated and is able to effectively control, combat, and eliminate the pathogen.

MOTIVATION (3 MINS) 1. Ask the students what they know of antibodiesand antigens.

What important events need to take place? (Answers are listed in the Instruction section of this guide) Get input from students regarding t hese questions. Comment on the correctness/ incorrectness of these answers. State how some of these topics will be discussed in today’s lecture. Specifically, the lecture will focus on how antibodiesare developed to target antigensfrom pathogenic organisms / substances.

Teacher Tip:

Definition:

Antibody is a protein produced by our immune system to specifically bind a target. Usually, these targets are parts of pathogens. Antigen is a substance / part of pathogen that generate an immune response. Usually this response leads to the production of a specific “antibody” for the given target.

INSTRUCTION (40 MINS) 1. The adaptive immune response has two aspects: the humeral and cellular response. 2. The humeral response is due to the production of antibodies by B-cells. I. B cells are white blood cells that develop and mature in the bone marrow. II. B cells are activated when they encounter antigen in the lymph nodes. III. Activated B cells produce antibodies, proteins that recognize and bind to specific parts of the pathogen, called antigens. Each B cell produces only one antibody which recognizes only one kind of antigen (specificity) 208

Discuss how the specific interaction between antigens and antibodies can be used to make “targeted” drugs. Answer: Drugs and other therapeautic agents can be attached to antibodies that are specific for antigens on cancer cells. This allows for specific targeting of these drugs to the diseased cells, thereby avoiding damage to healthy tissue .

Teacher Tip: Emphasize that the adaptive immune response is activated by the presence of foreign substances (proteins, nucleic acids, sugars, etc. found on pathogens).

IV. Antibodies are of five major types; IgM, IgD, IgG, IgA, and IgE. A. IgM is the first antibody produced. It coats the pathogen and promotes endocytosis by macrophages. B. IgG is a major antibody produced. It activates the other parts of the immune response and leads to neutralization and destruction of pathogen. C. IgA is the important antibody for the mucosal immune response. It prevents pathogens from crossing the epithelium and entering the blood stream. D. IgE activates mast cells and leads to the production of histamine, which is why it is also associated with allergic reactions. E. IgD. (The role of this antibody is still unclear at this point.) 3. The antibody response is best suited to combat pathogens that survive outside of the cell, such as bacteria, fungi, and some worms.

Teacher Tip: Also point out that although it is important to turn on the immune response during an infection, it is just as important that it is turned off after the infection is gone.

Answers for Practice Part: 1. 2. 3. 4.

B cells In the bone marrow IgE This person becomes very susceptible to diseases. They cannot effectively combat pathogens and can eventually die from even the mildest infections.

Teacher Tip: Most vaccines today contain an adjuvant

PRACTICE (5 MINS) Quiz

1. What type of cell produces antibodies? 2. Where are B cells produced? 3. The antibody involved in allergy is ______. 4. What will happen if a person cannot produce antibodies?

ENRICHMENT (5 MINS) Ask the students to think about what happens when they get vaccinated. How does a person get antibodies upon vaccination?

EVALUATION (5 MINS) Assignment: Make a comic strip showing the different types of antibodies and the roles they play in the immune response.

(substance that activates the innate immune response) along with a protein antigen from the pathogen, or an inactivated version of the pathogen which stimulates B cells to produce antibodies against the pathogen. After getting the vaccine, you now have cells that remember the pathogen and can act quickly when you actually get infected with the disease-causing organism. This memory of the B cells and quick response prevents the person from feeling any symptoms of the disease.

Teacher Tip: Check for the following features in the comic strip: 1. The five types of antibodies 2. The known functions of these antibodies 3. Highlight special features of each antibody based on sequence of production, amount produced, special shapes, etc.)

General Biology 2

60 MINS

Lesson 22.3: Compare and Contrast in Plants and Animals: Immune Systems (3 of 3) Content Standard

The learners demonstrate an understanding of the structures and processes involved in immune systems. Performance Standard

LESSON OUTLINE


5

Motivation

Inquiry

Instruction

Discussion of the Types of T Cells

Learning Competency

Practice

Quiz

5

The learners will be able to describe the importance of immune systems

Enrichment

Listing of Common Autoimmune Disorders

5

Evaluation

Exam


illustrate the functions of T cells

(STEM_BIO11/12-IVa-h-1) Specific Learning Outcomes


explain where T cells come from;

•

identify the different types of T cells and

•

describe the functions of T cells

5 40

10

Materials Art supplies for creating comic strips, paper / clay modelling materials

Resources (1) Immunology textbooks (e.g., Coico, Richard and Geoffrey Sunshine. Immunology: A Short Course (Coico, Immunology) 7th Edition. 2015. Wiley-Blackwell)

210


1. State the learning objectives as follows:

Teacher Tip: Point out that although antibodies are good at combating extracellular pathogens, they cannot eliminate pathogens found inside cells like viruses.

I. explain where T cells come from; II. identify the different types of T cells and III. describe the functions of T cells 2. The teacher will ask the students what they can recall in the past lessons.

“Our previous lectures discussed how the body deals with several Discussion Question: kinds of pathogens (e.g. bacteria, viruses, etc.). What is common among these examples?” Answer:

These are extracellular pathogens

3. Emphasize that the humoral immune response (B-cells) targets extracellularpathogens.

MOTIVATION (5 MINS)

Teacher Tip: Discussion Question: If you were controlling the immune system and you had to protect the body from a pathogen hiding within a “diseased” cell, what would you do? Possible answer:

If antibodies cannot eliminate intracellular pathogens, how does the immune system deal with these situations?

If you can’t eliminate the pathogen directly, perhaps it’s better for the system to quarantine/ eliminate the “diseased cell to prevent the spread of the infection.

1. This lecture focuses on the system that handles pathogens that are not easily accessible for the antibodies produced by B-cells. This system involves the function of another type of immune cell; the T-cells.

Is this practice also done in the organismal level? Can you think of institutions that practice the same system?

Question:



Quarantine:

(Cellular) Antibodies (Organismal) Quarantine Office (at airports) for Food safety and Biosafety. (Cellular) Antibodies (Organismal) Leper colonies

INSTRUCTION (40 MINS) 1. The adaptive immune system is due to the production of T cells. A. T cells are white blood cells that are produced in the bone marrow and mature in the thymus. B. T cells are activated when they encounter antigens in the lymph nodes. C. However, unlike B cells, T cells need to recognize an antigen in the context of selfmolecules called major histocompatibility complex (MHC) molecules. 2. There are 3 major types of T cells: cytotoxic T cells, helper T cells and regulatory T cells A. Cytotoxic T cells recognize virus-infected cells and kill them. B. Helper T cells secrete proteins that help other immune cells (B cells, macrophages, etc.) survive and perform their function. C. Regulatory T cells control the immune response by turning it off. This prevents the immune system from harming the body.

Teacher Tips:

PRACTICE (5 MINS)

1. 2.

1.

2.

3.

Explain that T cells have to recognize the foreign antigen in the context of a selfmolecule, the MHC molecule. This ensures that the immune system will only be activated when there is a real i nfection in the body. It is important to only activate the T cell response (particularly the cytotoxic and helper T response) only if there is a real infection because these responses are very potent and could potentially harm the body if they are not regulated properly. Regulatory T cells are very important because loss in their function can lead to autoimmune disease. This occurs when the immune system starts to attack itself.

Answer Key:

Quiz

1. Enumerate the types of T-cells. 2. What does the T in T-cells mean?

3. 4. 5.

3. Where are T cells produced? 4. Where do T cells mature? 5. What will happen if you lose all of your regulatory T cells?

212

Cytotoxic, Helper and Regulatory T-cells T stands for Thymus, where these cells mature. Bone marrow Thymus There is danger of developing an autoimmune disorder.

ENRICHMENT (5 MINS) The loss of regulatory T-cell function leads to autoimmune disorders. Ask the students for examples of these diseases. Common autoimmune disorders include rheumatic arthritis (“rayuma”) and lupus. What are the symptoms of these diseases, and how does T-cell dysfunction lead to their occurrence?

Answers: Rheumatoid Arthritis an autoimmune disorder where T-cells attack the lining of the joints. This leads to inflammation, joint deformation and bone erosion. (www.mayoclinic.org/diseases-conditions/ rheumatoid-arthritis) Lupus: There are several types of lupus. The most common is named systemic lupus erythematosus. T-cells attack the joints, skin, kidneys, heat, lungs, blood vessels and the brain in this autoimmune disease. Dysfunctional T-cell attacks lead to inflammation in these targets. (www.lupus.org.uk)

Answers to the Quiz:

EVALUATION (10 MINUTES) Quiz

1. Where are T-cells activated? 2. What does the acronym MHC mean? 3. What is the function of the MHC? 4. What happens to an individual who has had their thymus removed? Examinations can be given to test the students retention of the information provided in the lecture. Questions may be similar to the PRACTICE quiz. Alternatively, the students may be asked to do an assignment to show how they understood the concepts presented. 

1.

Lymph nodes

2. 3.

Major Histocompatibility Complex. The MHC serves as a signal for “self”/nonforeign cells. This allows the body to recognize tissues to reject. They cannot make mature T cells, but can still make mature B cells.

4.

Assignments could be in the form of: 1. Comic strips about the different kinds of T cells, and what they do in the immune response. 2. A dueling card game where the right type of T-cell should match the pathogen that it should combat (e.g. Magic card games; Modified Rock-Paper-Scissors). 3. Clay models of antigens bound in the MHC complex and their interactions with the T-cell receptors.

General Biology 2

90 MINS

Lesson 23.1: Compare and Contrast Process in Plants and Animals: Chemical and Nervous Control LESSON OUTLINE - DAY ONE

Content Standard

The learners demonstrate an understanding of plant and animal organ systems and their functions. Performance Standard


develop a presentation (e.g. role-playing, dramatization and other forms of multimedia) to show how an organism maintains homeostasis through the interaction of various organ systems in the body.


10

Motivation

Video clip

10

Instruction

Television Show Proper

60

Enrichment

Short Quiz

10

Materials Podcast, Short Videos

Resources

Learning Competency

The learners compare and contrast chemical and nervous control in plants and animals (STEM_BIO11/12-IVa-h-1 ) Specific Learning Outcomes


explain how animals respond to environmental stimuli;

•

describe the mechanisms of chemical and nervous control in animals;

•

explain how plants respond to environmental stimuli; and

•

describe the mechanisms of chemical control in plants.

214

(1) Responding to Environmental Changes- http://www.bbc.co.uk/ schools/gcsebitesize/science/add_ocr_21c/brain_mind/ environmentrev1.shtml (Retrieved 10/15) (2) Chemical Signals in Animals: http://web.calstatela.edu/faculty/mchen/ 433/Chem%20Sig%20Hormones.ppt (Retrieved 10/15) (3) The Endocrine System: http://www.shmoop.com/animal-systems/ endocrine-system.html (Retrieved 10/15) (4) The Nervous System: http://www.shmoop.com/animal-systems/ nervous-system.html (Retrieved 10/15) (5) Nerves and Hormones: http://www.rsc.org/Education/Teachers/ Resources/cfb/nerves.htm (Retrieved 10/15) (6) Comparing the Nervous and Endocrine Systems: https:// www.boundless.com/physiology/textbooks/boundless-anatomy-andphysiology-textbook/the-endocrine-system-16/overview-of-theendocrine-system-149/comparing-the-nervous-and-endocrinesystems-773-4975/ (Retrieved 10/15)



1. Communicate learning objectives as follows: I. Explain how animals respond to environmental stimuli II. Describe the mechanisms of chemical and nervous control in animals III. Explain how plants respond to environmental stimuli IV. Describe the mechanisms of chemical control in plants 2. Tell students that they will act as “resource persons” to talk about chemical and nervous control in animals. Explain to them that they are going to watch a class simulated television show and they will become participants.

Teacher Tip: Choose volunteers beforehand and tell them their specific tasks: host (1-2 students), resource speakers (3-5 students) and production crew ( 5 students). Tell them to prepare a script to be submitted to you a day before the show. Include an interesting and catchy title for the show. You may act like the producer of the show and discuss thoroughly with the volunteer students how a TV show is created.

MOTIVATION (10 MINS) Video Clip

This can be part of the television show.

1. Show the students a short podcast: Fight or Flight Response: https://www.youtube.com/ watch?v=m2GywoS77qc

Television S how Proper

1. The host will introduce the show and the guests (resource speakers). 2. The guests will discuss in an educational and entertaining manner how animals respond to environmental stimulus. 3. The host should make the show as interactive as possible by letting the audience (students) interact with the resource speakers.

To make the show more entertaining, tell the students not to make it too technical and engage the audience in the discussion.

4. The host/s will close the show.

The TV show may be done in two meetings to cover the discussions on Chemical and Nervous Control.


Prizes may be given as incentives for those who will interact during the show.

Lesson Proper:

Compared to plants, animals have chemical and nervous control that enable them to respond to environmental stimuli. Chemical control is under the regulation of the endocrine system and includes the various hormones. Chemical control is slow-acting but the effect is long-term. On the other hand, nervous control is under the regulation of the nervous system with its system of neuronal mechanisms. Nervous control is fast-acting and the effect is short-term, although frequent stimulation can be stored to produce a longer-lasting behavioral response.

Tell them to make a handout that will be distributed to the audience after the show. Assign some students to take a video of the show which will be shown a day after to the class.

Nervous System. The nervous system is the one responsible for coordinating the functions of the

Teacher Tip:

other body systems. The discussion of the system may focus on the following outline:

Choose volunteers beforehand and tell them their specific tasks: host (1-2 students), resource speakers (3-5 students) and production crew ( 5 students). Tell them to prepare a script to be submitted to you a day before the show. Include an interesting and catchy title for the show.

1. Divisions of the nervous system 2. The neuron as the basic unit 3. Transmission across synapse The nervous system gathers information, processes the information and elicits a corresponding response or reaction to the stimulus. The nervous system has two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is composed of the brain and the spinal cord. The brain is the main control center while the spinal cord connects the brain to other nerves of the body. The PNS is composed of nerves that branch out from the brain and the spinal cord to specific body parts and divided further into somatic and autonomic nervous system. The somatic nervous system controls voluntary body movements while the autonomic control involuntary actions. The diagram below shows the brief description of each division.

You may act like the producer of the show and discuss thoroughly with the volunteer students how a TV show is created.

This can be part of the television show.

To make the show more entertaining, tell the students not to make it too technical and engage the audience in the discussion. The TV show may be done in two meetings to cover the discussions on Chemical and Nervous Control. Prizes may be given as incentives for those who will interact during the show. Tell them to make a handout that will be distributed to the audience after the show. Assign some students to take a video of the show which will be shown a day after to the class.

From: http://pharmacologyview.blogspot.com (Last accessed 04/28/16, 3:00pm) 216

The basic structural and functional unit of the nervous system is the neuron. Once stimulated, a neuron transmits electrical signals called an action potential or an impulse across the system and lets a body part respond accordingly. Although neurons differ in some respects, they contain four basic parts: dendrite, soma, axon and axon terminals. The cell bodyor soma contains the nucleus and most organelles. The axon is a single projection from the soma which carries the impulse to the axon terminal. An impulse is a sudden change in the electric potential of the cell membrane. The axon may be enveloped by a myelin sheathfor faster conduction of impulse. The dendrites are several projections which extend outward from the cell body and receive chemical signals from the axon terminals of another neuron. Electrical disturbances in the dendrites or axon will cause a new wave of impulse down the axon. The diagram below shows a typical neuron with its parts and the direction of impulse transmission.

From: http://img.docstoccdn.com/thumb/src/99214785.png (Last accessed 04/28/16, 3:00pm)

Neurons connect with one another through a junction called synapse. The moment an action potential reaches the axon’s terminal, a series of events will be created leading to the stimulation of the next neuron. Chemicals called neurotransmitters are released which facilitate the transmission of an impulse across a synapse. The figure below shows a synapse and synaptic transmission.

From: http://faculty.pasadena.edu/dkwon/chap%208_files/images/image60.png 218

Endocrine Gland System. Chemical coordination of body functions is mediated by the endocrine

system, composed of ductless glands that release hormones. Hormones are chemical messengers secreted by a gland and affect a specific target tissue or organ. The endocrine and the nervous system coordinate with each other through a series of feedback mechanisms. A disorder results when a hormone is under- or over-secreted. The table below shows the major endocrine glands, the hormones that they release and their specific functions.

From: http://usdbiology.com/cliff/Courses/General%20Biology/153figs/47_02_endocrine_systemL.jpg (Last accessed 04/28/16, 3:00pm)

The diagram below shows a simple coordination between the nervous and the endocrine system.

From: http://csls-text3.c.u-tokyo.ac.jp/images/fig/fig05_07.jpg

EVALUATION (5 MINS) 1. What are the divisions of the nervous system? 2. Draw the structure of a neuron. 3. What is a synapse? 4. Define a hormone. 5. Differentiate the functions of the endocrine and the nervous system.

Teacher Tip: You may select some items from this sites: • http://footprints-science.co.uk/quizzes.php? difficulty=2&module=50§ion=1&type=Th e_nervous_system&quiz=yes&animation=&su bjectarea=Biology%201 • http://highered.mheducation.com/sites/ 0072437316/student_view0/chapter47/ chapter_quiz.html

220

90 MINS

General Biology 2

Lesson 23.2: Compare and Contrast Process in Plants and Animals: Chemical and Nervous Control LESSON OUTLINE - DAY TWO

Introduction Preview

5

Content Standard

Motivation

Observation

10

The learners demonstrate an understanding of plant and animal organ systems and their functions.

Instruction

Discussion on Plant Response

60

Evaluation

Take-home Activity

10

Enrichment

Short Quiz



develop a presentation (e.g. role-playing, dramatization and other forms of multimedia) to show how an organism maintains homeostasis through the interaction of various organ systems in the body.

Learning Competency

The learners compare and contrast chemical and nervous control in plants and animals (STEM_BIO11/12-IVa-h-1 ) Specific Learning Outcomes


explain how animals respond to environmental stimuli;

•

describe the mechanisms of chemical and nervous control in animals;

•

explain how plants respond to environmental stimuli; and

•

describe the mechanisms of chemical control in plants

5

Materials Podcast, Short Videos

Resources (1) Responding to Environmental Changes- http://www.bbc.co.uk/ schools/gcsebitesize/science/add_ocr_21c/brain_mind/ environmentrev1.shtml (Retrieved 10/15) (2) Chemical Signals in Animals: http://web.calstatela.edu/faculty/mchen/ 433/Chem%20Sig%20Hormones.ppt (Retrieved 10/15) (3) The Endocrine System: http://www.shmoop.com/animal-systems/ endocrine-system.html (Retrieved 10/15) (4) The Nervous System: http://www.shmoop.com/animal-systems/ nervous-system.html (Retrieved 10/15) (5) Nerves and Hormones: http://www.rsc.org/Education/Teachers/ Resources/cfb/nerves.htm (Retrieved 10/15) (6) Comparing the Nervous and Endocrine Systems: https:// www.boundless.com/physiology/textbooks/boundless-anatomy-andphysiology-textbook/the-endocrine-system-16/overview-of-theendocrine-system-149/comparing-the-nervous-and-endocrinesystems-773-4975/ (Retrieved 10/15)


INTRODUCTION (5 MINS) 1. Tell the students that although plants can’t move like animals, they also have mechanisms to perceive what is happening around them. 2. Plants can respond to environmental cues such as light and chemical signals and thus change their morphological and physiological features. MOTIVATION ( 10 MINS) Show the students several setups of seedlings in a box with holes. Ask the following questions: 1. What do you observe in these set-ups? 2. Are the seedlings exhibiting any form of reaction to environmental stimuli? 3. What are these stimuli the plants are reacting to? INSTRUCTION (60 MINS) 1. Post in front pictures of plants with some responses. Pictures that can be shown are as follows: A. Leaflets of makahiya plant closing (nastic movement) B. Sunflower growing in the sun’s direction (phototropism) C. Tendrils of a vine around a pole (thigmotropism) D. Venus flytrap trapping an insect (thigmotropism) E. Roots of a plant growing underground (geo- and hydrotropism) 2. Call some students to identify these specific responses. 3. Discuss the importance of these responses in the survival of plants. 4. Explain the role of hormones in coordinating plant physiological mechanisms. (Six volunteers may be asked to present a brief report on plant hormones.) 5. Show a short video at the end of the discussion. PLANT RESPONSE

All living things respond to environmental stimuli primarily to survive. Plants, which are sessile (stationary) exhibit responses to stimuli such as light, water, touch and wind. Responses are important to get a needed nutrient, survive a certain condition (such as extreme weather changes) or defend itself from predators and to reproduce. The sensitive plant, Mimosa pudica, locally 222

Teacher Tip: This set-up should be prepared a week in advance in order for the seeds to germinate just in time f or the demonstration. (1) Prepare a shoe box with a hole on top, as shown below. (2) Half-fill two small plastic cups with soil and plant one kidney bean in each cup. (3) Put the cups inside, one under the side with hole. (4) Set aside for a week. Don’t forget to put some amount of water every other day.

Teacher Tip: The students must realize that all living things respond to environmental stimuli as one of their characteristics. They must be able to differentiate how plants compare with animals in terms of the specific response and why such response is important. Let them define the words STIMULUS and RESPONSE.

called “makahiya”, closes its leaflets once touched. The sunflower moves toward the direction of the sun. The stomata close in response to rapid loss of water. The seeds of some plants need to be burned to trigger seed germination. Recent studies also show that some plants can release chemicals that act as defense mechanisms against pathogen and predators and warn nearby plants to prepare for an impending attack. Tropism is a biological mechanism that enables plant to move toward (positive tropism) or against (negative tropism) the source of a stimulus. The roots grow underground because they usually move toward the source of water and the center of gravity while leaves usually grow above ground where they absorb sunlight. The table below shows a list of responses in plants.

Teacher Tip: - anything STIMULUS

in the environment (light, water, heat, pressure, wind, touch, etc) that triggers a physiological change in an organism - the corresponding RESPONSE

reaction to an environmental stimulus. In the long run, a series of responses will enable an organism to adapt and survive. Ask volunteers to report on the following plant hormones: 1. Auxin 2. Gibberellin 3. Abscissic acid 4. Ethylene 5. Cytokinin The following sites have materials which you can modify for your discussion. 1. http://www2.nsysu.edu.tw/Bio/images/ commen/plant-horm10303.pdf 2. http://bio.fsu.edu/~outlaw/shared/BOT %203015L%20(Laboratory)/05-Plant-GrowthHormones.ppt 3. http://ljhs.sandi.net/faculty/RTenenbaum/apbiology-folder/7thedition/ch3908_files/ ch3908.ppt 4. http://www.unionps.org/filesSiteEmployee/ 17/2291/Plant%20Tropisms%202011.pptx 5. http://peer.tamu.edu/NSF_Files/Plant %20Tropisms.ppt 6. peer.tamu.edu/NSF_Files/Plant Tropisms.ppt

From: http://catholicscienceteacher5.blogspot.com/2013/12/plants-tropisms-hormones.html

Hormones are chemical messengers in plants. They regulate various biochemical and physiological responses that include seed germination, flowering, photosynthesis, fruit ripening and shoot and root development. The table below shows a list of plant hormones and their specific actions.

From: http://plantbiotechinfo.blogspot.com/2011/10/plant-hormones-and-growthregulators.html 1. What is a stimulus and what is a response? 2. Give one stimulus and the corresponding response of a plant. 224

ENRICHMENT (5 MINS) 1. Read the article “How Plants Secretly Talk to Each Other”. Summarize in your notebook what you learned from the article. 2. Watch short videos on plant responses and hormones. EVALUATION (5 MINS) 1. Give a short quiz on plant response and functions of hormones

Teacher Tip You may select some items from this sites: • http://highered.mheducation.com/sites/ 0072919345/student_view0/chapter27/ multiple_choice_quiz.html • http://highered.mheducation.com/sites/ 0072347201/student_view0/chapter18/ multiple_choice_quiz.html • http://www.cliffsnotes.com/study-guides/ biology/biology/vascular-plants-structure-andfunction/quiz-plant-hormones

ADDITIONAL RESOURCES:

1. Tropism- https://en.wikipedia.org/wiki/Tropism (Last accessed 05/01/16) 2. Hormonal Sentience: https://en.wikipedia.org/wiki/Hormonal_sentience (Last accessed, 05/01/16) 3. Endocrine System: Control and Coordination - https://www.youtube.com/watch?v=HNk5JdMUmno 4. Central Nervous System- https://www.youtube.com/watch?v=oHgg4S9xIiA 5. Fight or Flight Response: https://www.youtube.com/watch?v=m2GywoS77qc 6. Mimosa pudica: the Sensitive Plant - https://www.youtube.com/watch?v=BLTcVNyOhUc (Last accessed, 05/05/16) 7. Flesh-eaters: Carnivorous Plants Lure Insects Into their Deadly Clutches - https://www.youtube.com/watch?v=MnY_cCRELvs (Last accessed, 05/05/16) 8. Plants Tropisms and Hormones - https://www.youtube.com/watch?v=pCFstSMvAMI (Last accessed, 05/05/16) 9. Plant Control - http://catholicscienceteacher5.blogspot.com/2013/12/plants-tropisms-hormones.html (Last accessed, 05/05/16) 10. Control and Coordination http://old.nios.ac.in/secscicour/CHAPTER28.pdf (Last accessed 04/28/16, 2:29pm) 11. How Plants Secretly Talk to Each Other - http://www.wired.com/2013/12/secret-language-of-plants/ (Last accessed 05/01/16)

General Biology 2

90 MINS

Lesson 24.1: Compare and Contrast Processes in Plants and Animals: Sensory and Motor Mechanisms (1 of 2) LESSON OUTLINE

Content Standard

The learners demonstrate an understanding of sensory mechanisms in animals.



Motivation

Importance of Senses

10


Instruction

Lecture

45

Drawing Activity Enrichment Small Group Discussions

15

5

• draw and label the parts of the human eye and human ear. Practice

Learning Competency

The learners should be able to describe the structures involved in major animal senses (STEM_BIO11/12-IVa-h-1)

Evaluation

Quiz

10 5

Materials Writing and drawing materials (bond paper, ball pen, pencil, coloured pens, Manila paper



Resources

•

describe the five types of sensory receptors;

•

illustrate the three types of eyes in animals;

•

explain how vision occurs in humans;

•

differentiate the parts of the human ear and describe the functions of each; and

•

discuss how the senses of smell and taste detect chemicals.

(1) Audesirk, T, Audesirk G and Byers DE. 2002. Biology. Life on Earth. (6th edition). Prentice-Hall, Inc. 892 p. (2) Campbell, N, Mitchell L and Reece J. Biology. Concepts and Connections. (3rd edition). Addison Wesley Longman. 809 p. (3) Reece, JB, Urry LA, Wasserman SA, Minorsky PV and Jackson RB. 2011. Campbell’s Biology. (10 edition). Benjamin Cummings. 1488 pp.

226

INTRODUCTION (5 MINS) Review of Prerequisite Knowledge

1. The previous topics on the central and peripheral nervous system should be mentioned. Transmission of a nerve impulse should be recalled.

Teacher Tip You may begin the class with a thought experiment and ask the class what will happen if any of their sense organs stop to function. The learners may answer orally or in a piece of paper.


1. The learning objectives will be given and the following topic outline will be written on the board: A. Sensory receptors- mechanoreceptors, thermoreceptors, chemoreceptors, photoreceptors and pain receptors B. Three types of eyes in animals C. Parts of the human eye and how “seeing” occurs D. Parts of the human ear and how hearing is achieved E. The senses of smell and taste

MOTIVATION (10 MINS) Sample Class Activities

1. Ask learners how different animals sense their environment (Examples: dogs sniffing chemicals; salmon returning from the sea swimming upstream at times to spawn in freshwater; echolocation in bats; vision perception in birds and bees) 2. Learners may be asked to touch the smooth and rough surfaces of a chair or table 3. Looking at an object very near to the observer and gradually increase the distance of the object away from the observer 4. With eyes closed, determine the source of a sound, whether on the left or right.

INSTRUCTION (40 MINS) Lecture

1. The five sensory receptors are: - respond to light I. Photoreceptors - respond to physical stimuli such as sound or touch II. Mechanoreceptors - detect chemicals III. Chemoreceptors

Misconception Extrasensory perception may be mentioned and discussed how it might be difficult for scientists to prove the existence of such traits.

- respond to temperature IV. Thermoreceptors - detect possible tissue damage V. Pain receptors 2. The three types of eyes that have evolved in the animal kingdom are: I. Eye cups in flatworms and other invertebrates II. Compound eyes in insects and arthropods III. Single lens eyes in squid 3. Describe the parts of the human eye The sclerais the outermost layer of the eyeball. It forms the white of the eye and in front, there is a transparent cornea. The conjunctivalines the eyelids and the front of the eyeball. It helps keep the eyes moist. The sclera surrounds the choroid. The iris giving the eye its color, is formed from the choroid. Vision starts when light passes through the pupil and into a transparentlens that focuses images on the retina. The retina contains photoreceptor cel ls which transduce light energy into action potentials. These nerve impulses travel along the optic nerveto the corresponding visual areas of the brain. An image is then formed. 4. The photoreceptor cells are rods and cones I. Rod cellsuse the pigment called rhodopsin. They are used for night vision and can detect only shades of gray and not color. II. Cone cellsdistinguish various colors and they are sensitive to bright light. 5. Explain how hearing is possible in the human ear The outer ear lobescatch sound waves and channel them to the eardrums. From the eardrum, the middle ear amplifies the sound wave vibrations to three small bones – the hammer, anviland stirrup. The sound waves travel to the oval window. The Eustachian tubeequalizes air pressure in the middle ear and outer ear. The hearing organ is in the inner ear, composed of several channels of fluid wrapped in a spiral cochlea. This is encased in the bones of the skull. Vibrations in the oval window produce pressure waves. These waves travel through the upper canal to the tip of the cochlea, enter the lower canal and fade away. Pressure waves of the upper canal push down to the middle canal and the membrane below this canal vibrates. These vibrations stimulate hair cells 228

Teacher Tip: Use colored diagrams or illustrations.

attached to the membrane by moving them against the overlying tissue. The hair cells are able to develop receptor potentials causing release of neurotransmittersthat induce action potentials in the auditory neurons. 6. Illustrate how odor and taste senses are achieved The senses of odor and taste are interrelated. Chemoreceptors in the nose detect molecules, differentiated into numerous types of odor. In the upper portion of the nasal cavity, there are olfactory chemoreceptors. Odor molecules enter the nose and bind to specific receptor molecules on the chemoreceptor cilia. This event triggers receptor potentials.

Teacher Tip: Use colored diagrams or illustrations.

In the tongue, chemoreceptors in taste buds detect salty, bitter, sweet and sour tastes. Taste perception is due to similar signal mechanisms as mentioned above for smell. What one “tastes” is actually “smell” or odor. The common cold (due to a virus) can disrupt our sense of smell, thus, we lose taste for the food.

PRACTICE (15 MINS) Drawing Activity

1. With a colored diagram, point out the parts of the human eye, ear, and the taste buds in the tongue. 2. In the diagram for the eye, trace the path of light which is converted to an image that one sees. Similarly, in the diagram for the ear, trace the events that lead to hearing sensation.

Teacher Tip: For discussion : Challenge the learners to redesign the human eye and ear for better adaptation.

3. Ask learners to make their own diagram for the human eye and ear by simple recall.

ENRICHMENT (10 MINS) Small Group Discussions

1. What is normal human vision? How are visions for nearsighted, farsighted and astigmatic persons corrected by lenses? 2. If you are in a dark room, why is it that you don’t see any colors? What cells are active in the dark?

Teacher Tip: Consult the internet and for more enrichment activities/ authentic assessment.

EVALUATION (5 MINS)

Answer Key: 1. 2. 3. 4.

Quiz

1. Which of the following does not belong to the group? A. Cornea B. Anvil C. Pupil D. Rods E. Sclera 2. A receptor absorbs the energy of a stimulus by means of A. Reception B. Transmission C. Amplification D. Transduction E. Integration 3. Sensory receptors that respond to touch and pressure are called _____________. 4. Differentiate the function of rod cells from cone cells.

ASSIGNMENT 1. Explain echolocation in bats. 2. Discuss the evolution of the vertebrate eye. 3. What causes motion sickness?

230

Anvil

Transduction Mechanoreceptors In the dark, rod cells are active but when there is light, colors can be seen due to cone cells.

General Biology 2

90 MINS

Lesson 24.2: Compare and Contrast in Plants and Animals: Sensory and Motor Mechanisms (2 of 2) LESSON OUTLINE

Content Standard

The learners demonstrate an understanding of animal organ systems for locomotion and movement and their functions.


5

Motivation

Diagram of the Skeletal System

10


Instruction

Lecture

45

• describe the importance of animal movement/locomotion; • explain the functions of a skeletal system;

Practice

Recitation

15

Enrichment


10

Evaluation

Quiz


• illustrate the interaction of skeleton and muscles in movement; and • discuss how much motor neurons stimulate muscle contraction. Learning Competency

5

Materials

The learners should be able to describe structures and functions of organs involved in sensory and motor systems. (STEM_BIO11/12-IVa-h-1)

Microscopes, prepared slides of bone and muscle tissues, diagrams and models of frog and human skeletal and muscular systems, writing and drawing materials


Resources


(1) Audesirk, T, Audesirk G and Byers DE. 2002. Biology. Life on Earth. (6th edition). Prentice-Hall, Inc. 892 p.

•

describe diverse means of animal locomotion;

•

differentiate the three types of skeletal systems: hydrostatic, exoskeleton and endoskeleton;

•

enumerate the parts of the frog skeleton; and

•

explain how a muscle contracts.

(2) Campbell, N, Mitchell L and Reece J. Biology. Concepts and Connections. (3rd edition). Addison Wesley Longman. 809 p. (3) Reece, JB, Urry LA, Wasserman SA, Minorsky PV and Jackson RB. 2011. Campbell’s Biology. (10 edition). Benjamin Cummings. 1488 pp.


Teacher Tip:


1. Present the topic outline for Sensory and Motor Mechanisms. Emphasis that today’s topic will center on Motor System. 2. The topic outline for Motor Systems can be presented as: I. Animal Locomotion

(Explain that) ..movement is obvious in animals but plants can exhibit movement in several ways: plant parts grow towards the light; xylem and phloem cells move materials on the plant b ody. Plants can move or show their own version of “locomotion”.

II. Skeletal Systems III. Human Skeletal System IV. Muscle cells V. Muscular contraction 3. Cite the specific learning objectives for this topic.

MOTIVATION (10 MINS) Diagram of Skeletal System

Teacher Tip:

1. Show a diagram of the human skeletal and muscular system. Point out the major bones and muscles on the arms, legs and torso.

Plastic models of the human skeleton are available in toy stores.

2. Explain the occurrences of some disorders like polio and muscular dystrophy.

INSTRUCTION (40 MINS) Lecture

1. Describe the importance of locomotion in various animal activities: Animals have to move to find food and sexual partners. To avoid predators and adjust to varying environmental conditions, animals exhibit different ways of moving. Ask learners other examples and uses of animal movement, e.g. in ants, lizards, earthworm. 2. Show, using visuals, several means of animal locomotion: walking, running, swimming, flying, crawling, hopping, gliding. 3. Explain the three types of skeleton. 232

occurs in a body compartment in I. Hydrostatic skeleton which a volume of fluid is held under pressure. This is common in aquatic and burrowing animals. An example is the Hydra and other invertebrates with a semi-enclosed body cavity made of a few layers of cells. There is no solid “bone” but the animal under aquatic pressure can stay upright and move. Earthworms have smooth muscles and fluid-filled body compartments.

6. Explain the sliding filamenttheory of muscular contraction.

II. Rigid, armor-like coverings characterize an exoskeleton. Muscles are attached inside. Joints are thin and flexible. The best examples are found in arthropods (insects, crustaceans). When insects grow, they shed off their old “armor” and grow a new one. Cite other examples such as those in clams and snails.

PRACTICE (20 MINS)

III. An endoskeletonconsists of rigid but flexible support made of bones, cartilage surrounded by masses of muscles. In sponges, cells are supported on spicules. The endoskeleton of echinoderms is made from calcium plates underneath the skin. 4. Distinguish the axial skeleton from the appendicular skeleton: I. Axial skeleton– skull and backbone (spiral cord); rib cage – bones of the appendages (arms, II. Appendicular skeleton legs, fins) and bones linking the appendages to the axial skeleton – the pectoral and pelvic girdles 5. Draw on the board the differences among striatedor skeletal muscle, smooth muscle and cardiac muscle . Illustrate the parts of a striated muscle as seen in an electron photomicrograph. Locate the following parts: dark band; light band; A-band; Iband; Z line; sarcomere; myosin; actin filaments; troponin; tropomyosin

7. The thin myofilaments, actin, stay at the center and the thick myofilaments, myosin, slide past one another. Every muscle that contracts is therefore a “pull” not a push. You can demonstrate this by interlocking your fingers and sliding them past one another.

Recitation

1. Find a method for the learners to submit a clean, complete properly labeled skeletal system of a frog/toad. 2. With a compound microscope, allow the learners to examine a cross-section oftoa locate mammalian compactsystems. bone. Use the low power objective (LPO) the Haversian 3. Ask the learners to switch between LPO and high power objective (HPO). Point out and draw the following structures: Haversian canal, lamellae, lacunae, canaliculi. Bone cells or osteocytes are deposited in lacunae. 4. With a clean, big toad skeleton point out the major bones of the skull, vertebral column, pectoral girdle, pelvic girdle, anterior and posterior limbs. 5. Using a compound microscope, examine and draw the three types of muscles: smooth, striated and cardiac. Ask the learners to describe their differences. Use the HPO to get more details. 6. With a diagram, point out to the learners the major muscles in the frog/toad abdomen and the ventral side of the posterior limb.


Teacher Tip: Toads are better to use since they are more abundant and the bones are big ger. Advise the learners to be careful in making the toad skeletal system (which could be a group project). A book atlas on frog and human anatomy may be used as reference.


1. What happens during a “sprain”? 2. Give examples of skeletal disorders (arthritis, osteoporosis) and their causes.


1. A muscle cell is also referred to as a A. Sarcoplasm B. Myofibril C. Muscle fiber D. Muscle bundle E. Myofilament 2. Peristalsis is due to what type of muscle? A. Smooth

3. Diverse adaptations for animal movement are mainly due to: A. Nervous systems B. Skeletal system C. Muscular system

Answer Key: 1. 2. 3. 4.

Muscle fiber Smooth B and C Scapula

D. Both A and B E. Both B and C 4. Which of the following does not belong to the group?

B. Striated C. Cardiac

A. Femur B. Tibio-fibula

D. Skeletal E. Voluntary

C. Scapula D. Phalanges E. Tarsals

ASSIGNMENT 1. Describe each of the following muscle actions: levator, depressor, flexor, rotator, dilator, constrictor, adductor 2. Explain how a motor neuron stimulates muscle contraction 3. On the cellular level, describe the steps that lead to the sliding filament theory of muscular contraction.

4. Differentiate: A. B. C. D. 234

Bone vs. Cartilage Compact bone vs. Spongy bone Tendon vs. Ligament Osteocyte vs. Chondrocyte

General Biology 2

120 MINS

Lesson 25.1: Feedback Mechanisms

LESSON OUTLINE

Introduction Communicating Learning Objectives Motivation

Content Standard

The learners demonstrate an understanding of feedback mechanisms. Performance Standard


develop a presentation (e.g. role-playing, dramatization and other forms of multimedia) to show how an organism maintains homeostasis through the interaction of the various organ systems in the body.

Learning Competency

The learners should be able to explain how some organisms can maintain steady internal conditions (STEM_BIO11/12-IVi-j-2) Specific Learning Outcomes


explain the need for homeostasis; and

•

describe how various organs systems enable homeostasis

Instruction Human Body Systems Campaign and Practice Assignment

5 5

Survey Says

Essay Writing

100 10

Materials Reference materials with information about the human body systems, computer with internet access, pencils, colored pencils or crayons, markers, manila paper, scissors, paste/ glue

Resources (1) InnerBody- http://www.innerbody.com (Retrieved 10/15) (2) The Human Body: Anatomy, Facts and Functions: http://www.livescience.com/ 37009-human-body.html (Retrieved 10/15) (3) Body Systems: http://www.mananatomy.com/body-systems (Retrieved 10/15) (4) Brain Pop: https://www.brainpop.com/health/bodysystems/humanbody/ preview.weml (Retrieved 10/15) (5) Get Body Smart: http://www.getbodysmart.com/ap/systems/tutorial.html (Retrieved 10/15) (6) Human Body: http://science.nationalgeographic.com/science/health-and-humanbody/human-body/ (Retrieved 10/15) (7) Body Maps: http://www.healthline.com/human-body-maps (Retrieved 10/15) (8) Body Systems: http://www.infoplease.com/dk/science/encyclopedia/bodysystems.html (Retrieved 10/15) (9) Science: Human Body and Mind. http://www.bbc.co.uk/science/humanbody/ body/index_interactivebody.shtml (Retrieved 10/15) (10) Human Organ Systems: http://www.quia.com/rr/269891.html (Retrieved 10/15) (11) All Systems Go: http://sciencenetlinks.com/interactives/systems.html (Retrieved 10/15) (12) Human Body Games: http://www.gamequarium.com/humanbody.html (Retrieved 10/15) (13) Oakland Schools Biology Resource Unit http://www.oakland.k12.mi.us/ LinkClick.aspx?link=Learning/Biology+Resource+Unit5+final.doc


Teacher Tip:


1.

Divide the class into 11 groups to cover all the systems: A. Integumentary B. Skeletal C. Muscular D. Digestive E. Excretory F. Respiratory G. Circulatory H. Immune I. Endocrine J. Nervous K. Reproductive

2.

Assign one body system to each group. If there are not much l earners to cover 11 groups, 2 systems may be handled by one group.

3.

Distribute the Worksheets on Body System Campaign (A) and the Rubrics for Grading (B) to each group.

1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can explain why homeostasis is important to organisms. II. I can describe how structures and processes maintain homeostasis.

MOTIVATION (5 MINS) Survey Says

1. Engage the learners in a class activity by making a simple (online) survey. Use the Survey Monkey (or any similar online survey applications) on which organ system learners think as the most important in maintaining homeostasis. 2. Give learners time to create an internet account. 3. Once everyone has registered, they can start voting by clicking on the organ system they believe is the most important. 4. The teacher should devise a mechanism so that the learners can see the results of the voting on the spot. 5. If computers are not available, learners can just vote in class by raising their hands. The teacher can just tally the results on the board. The learners can vote up to 3x.)

(Results tend to vary between classes, but

INSTRUCTION/DELIVERY (100 MINUTES)

Note: Numbers 4-7 may be done if there is enough time.

DAY 1: HUMAN BODY SYSTEMS CAMPAIGN

1. The learners will research on their assigned body system using reference materials and computers with internet access. 2. Once research is done, learners should obtain a sheet of manila paper to write their data. 3. Spread out the paper and choose a member who is as tall as the paper. 4. Placing the paper flat on the floor, have that member of the group lay on his/her back on the paper while the other members of the group trace his/her outline in pencil. 5. Label the manila paper with the name of their body system and using their research results draw in and label all parts/organs of the system on the outline in their respective positions. (They may also 236

there usually is not a clear ‘winner’.) The class discussion should center on why there is no clear winner.

The attached handouts may be modified by the teacher to suit the needs of the class.

draw the part on colored papers and attach these on the manila paper using paste or glue.) 6. Once drawn, they should color their life-size representation. 7. When the representation is complete, the group should organize the presentation of their campaign by completing the function of the system, parts/organs, and their concluding description of the importance of their system. The group must be able to discuss or present mechanisms and processes in the system that contribute to homeostasis. 8. The learners may bring home their presentation to finalize the details for a successful campaign. 9. The learners should be ready with possible negations that the other groups might raise against their organ-system.

Teacher Tip: 1.

Pose this question to learners ‘Why is there not one system that is most essential to the survival of the human species?’

2.

Distribute handout D, go over the rubric with learners, and ask them to answer the question in writing. Collect the essay and with the rubrics attached on it within a reasonable amount of time given to the learners.

Wrap Up

1. Tell the learners to continue improving their output and be ready with their presentation next meeting. DAYS 2 and 3: HUMAN BODY SYSTEMS CAMPAIGN

1. Let all the groups post their output in front of the class. 2. Call on each group to present their output. This can be done in order based from the list or drawn at random. 3. Call 2 representatives from each group to present within 4 minutes why their system is the most important for human survival. The other learners should take down notes about each system and write possible points to refute. 4. Once all the groups have presented, allow each group to finalize their rebuttal. 5. Rebuttal should be from 2-3 minutes and everyone should be quiet. Remind learners that this is not the time to argue with each other. 6. Slips of paper containing all the systems (handout C) will be distributed. The learners will again vote for the system they now feel is the most essential for the survival of the human species. 7. Tally the votes and let the learners see the results. EVALUATION

Note:

1. Check the content of the output using handout B.

This will also serve as an ENRICHMENT activity. Give the learners one day to compose their essay. Use handout D to evaluate their essay.

Assignment

1. Essay Writing - ‘Why is there not one system that is most essential to survival of the human species?’

General Biology 2

75 MINS

Lesson 25.2: Feedback Mechanisms Content Standard

LESSON OUTLINE

The learners demonstrate an understanding of feedback mechanisms.




develop a presentation (e.g. role-playing, dramatization and other forms of multimedia) to show a simple feedback mechanism that leads to homeostasis

Learning Competency

The learners should be able to describe examples of homeostasis (e.g.,

5

Motivation

Homeostasis: A Balancing Act

10

Instruction

Lecture on Homeostasis

40

Evaluation

Inquiry

10

Enrichment

Research on Disorders

10

Materials

temperature regulation, osmotic balance and glucose level regulation) and the Stopwatch, videos, podcasts major features of feedback loops that produce homeostasisSTEM_BIO11/12( Resources IVi-j-3) (1) Notes for Homeostasis and Excretion- http://tfssbio.pbworks.com/f/ Specific Learning Outcomes


explain the need for homeostasis;

•

differentiate positive and negative feedback mechanisms;

•

outline the homeostatic control of temperature regulation, osmotic balance and glucose level regulation; and

•

describe some disorders that result from the disruption of homeostasis.

238

Homeostasis+Notes09.pdf (Retrieved 11/15) (2) Human Physiology/ Homeostasis- http://www.saylor.org/site/wpcontent/uploads/2010/11/Homeostasis-Overview.pdf (Retrieved 11/15) (3) Homeostasis: http://bio5090.wikispaces.com/file/view/Homeostasis +note.pdf (Retrieved 11/15) (4) Homeostasis: http://igbiologyy.blogspot.com/2014/03/133homeostasis.htmlweml (Retrieved 11/15) (5) Homeostasis: http://www.passbiology.co.nz/biology-level-3/ homeostasis (Retrieved 11/15) (6) Homeostasis Game: http://www.purposegames.com/game/ homeostasis-game-game (Retrieved 11/15) (7) Homeostasis: A Balancing Act . http://www.msichicago.org/fileadmin/ Education/learninglabs/lab_downloads/Homeostasis.pdf (Retrieved 11/15) (8) Homeostasis: https://www.youtube.com/watch? v=_0afKWu4yVg&spfreload=10 (Retrieved: 11/15 )


1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud) I. I can explain why there is a need for homeostasis II. I can explain how feedback mechanisms maintain homeostasis III. I can differentiate a positive from a negative feedback IV. I can outline some ways by which our body maintains homeostasis

Teacher Tip: The human body is composed of various organs with specific functions. Organs assemble to form organ-systems that contribute to homeostasis inside the organism. Homeostasis is the condition wherein steady state is regulated inside the organism in order for it to adapt to internal and external changes. This is important for survival. Once homeostasis is disrupted, the organism may experience a disorder that might affect its normal functions.

MOTIVATION (10 MINS) Homeostasis: A Balancing Act

Teacher Tip:

1. Ask all learners to stand up and balance themselves on one foot. After one minute, tell them to put their other foot down. Let them share with each other what they experienced. Tell them to take their resting pulse for 15 seconds. Multiply this by 4 to have their pulse rate in 1 minute.

After the activities, ask 3 volunteers to share their experiences.

2. Tell them to jog in place for 1 minute then take their pulse again for 15 seconds. Multiply this by 4 to have their pulse rate in 1 minute. Let them share with each other what they experienced.

Tell the learners that they just experienced homeostasis.

INSTRUCTION (40 MINS) 1. Ask the following questions: What is homeostasis? In the previous activities, how did the body maintain homeostasis? What factors can disrupt homeostasis in the body? 2. Introduce the concept of feedback mechanism. What does the word feedback mean? With what do you associate this term? Can you give an example of a feedback? Why is a feedback important in the body? 3. Show the following video about homeostasis. I. Positive and Negative Feedback Loops: Post this video (https://www.youtube.com/watch? v=CLv3SkF_Eag&spfreload=10) (Retrieved 11/15) or show diagrams and pictures and explain what homeostatic mechanisms took place. Then ask, “How was the system maintained?”

In the second activity, respiration rate will increase during exercise due to the i ncrease in carbon dioxide. The heart rate will increase in order to remove the extra carbon dioxide and increase the amount of oxygen. When things are normalized, the heart rate will go back to the resting state. How long does it take for this to happen?

Teacher Tip: Discuss briefly what a feedback is. You may give as an example the report card that they get every Quarter or grading period. What are shown in a report card? What is the purpose of a report card? To pass the subject, what grade must you get? If you are running for honors, what is the acceptable range for your grades? How will you reach your target grades? Likewise, tell them that the body works at a certain range of conditions (such as blood glucose level, body temperature and blood pH). Diseases normally disrupt these conditions and the body must try to return the conditions back to normal.

Homeostasis is the physiological consistency of the body despite external fluctuations. All complex multicellular organisms maintain a stable internal environment using their organ systems. Homeostasis in a general sense refers to stability, balance or equilibrium. It is the body's attempt to maintain a constant internal environment. Maintaining a stable internal environment requires constant monitoring and adjustments as conditions change. The adjustment of physiological systems within the body is called homeostatic regulation. 240

The learners should understand the following about homeostasis. • The main parts and functions of the homeostatic control system. (What it does and what structures are used and why) • The mechanism of this control system, i.e. How and why it responds to the normal range of environmental fluctuations, the interaction and feedback mechanisms between parts of the system? • How balance is re-established following the potential effect of one specific disruption- (What occurs in the system to return the fluctuation back to the normal internal physiological state) • Explain an example of a negative feedback being broken.

The homeostatic control has three components: II. A receptor(sense organ) to detect a change (the brain or the spinal cord) that will process and integrate what is happening III. A center of control IV. An effector(muscle cells or organs/ glands) to produce a response appropriate to the change. There are ways of communication among these components (basically through the nervous and endocrine control). When a change of variable occurs, there are two main types of feedback to which the system reacts: : a reaction in which the system responds in such a way as to reverse 1. Negative feedback the direction of change. I. Thermoregulation II. Carbon dioxide concentration III. Blood sugar level : a response is occurs to amplify the change in the variable. (This has a 2. Positive feedback destabilizing effect, so does not result in homeostasis. Positive feedback is less common in naturally occurring systems than negative feedback, but it has its applications.) I. For example, in nerves, a threshold electric potential triggers the generation of a much larger action potential. II. Blood clotting III. Events in childbirth

EVALUATION (10 MINS) 1. Give examples of feedback mechanisms in the body.

ENRICHMENT (10 MINS) 1. Describe the homeostatic control of the following: I. blood glucose level II. temperature regulation III. water and salt balance IV. carbon dioxide concentration Assignment:

1. Research on the following disorders. Discuss how homeostasis is disrupted. Form a group with 5 members I. Diabetes mellitus II. Hemophilia III. Hemorhagic fever IV. Hypothermia V. Diarrhea 2. Prepare a 5 – 10 slide presentation about your topic. You will be evaluated by your classmates using the rubrics. 3. Each will be given a maximum of 10 minutes to present.

242

Lesson 25.3: Feedback Mechanisms Content Standard

LESSON OUTLINE

The learners demonstrate an understanding of feedback mechanisms Performance Standard


develop a presentation (e.g. role-playing, dramatization and other forms of multimedia) to show a simple feedback mechanism that leads to homeostasis

60 MINS


5

Motivation

Review on Past Topic

Instruction

Reporting

40

Evaluation

Quiz

10

5

Learning Competency

Materials

The learners should be able to describe examples of homeostasis (e.g., temperature regulation, osmotic balance and glucose level regulation) and the

Stopwatch, videos, podcasts Resources

major features of feedback loops that produce homeostasisSTEM_BIO11/12( IVi-j-3)

(1) Notes for Homeostasis and Excretion- http://tfssbio.pbworks.com/f/ Homeostasis+Notes09.pdf (Retrieved 11/15) (2) Human Physiology/ Homeostasis- http://www.saylor.org/site/wpcontent/uploads/2010/11/Homeostasis-Overview.pdf (Retrieved 11/15) (3) Homeostasis: http://bio5090.wikispaces.com/file/view/Homeostasis +note.pdf (Retrieved 11/15) (4) Homeostasis: http://igbiologyy.blogspot.com/2014/03/133homeostasis.htmlweml (Retrieved 11/15) (5) Homeostasis: http://www.passbiology.co.nz/biology-level-3/ homeostasis (Retrieved 11/15) (6) Homeostasis Game: http://www.purposegames.com/game/ homeostasis-game-game (Retrieved 11/15) (7) Homeostasis: A Balancing Act . http://www.msichicago.org/fileadmin/ Education/learninglabs/lab_downloads/Homeostasis.pdf (Retrieved 11/15) (8) Homeostasis: https://www.youtube.com/watch? v=_0afKWu4yVg&spfreload=10 (Retrieved: 11/15 )



explain how homeostasis is disrupted during a disease or disorder; and

•

explain how the body restore homeostasis after a disease or disorder

INTRODUCTION (5 MINS) Introduce the following objectives by asking volunteers to read them aloud. I. I can explain how homeostasis is disrupted during a disease or disorder. II. I can explain how the body restore homeostasis after a disease or disorder.

MOTIVATION (5 MINS) 1. A learner will give a short review of the past topic. Teacher Tip:

INSTRUCTION/DELIVERY (40 MINS)

Tell the learners that each member must share something to the report. Everyone must be able to talk during the reporting. I f a group exceeds the allotted time, they are disqualified for the prize

1. Draw lots on the order of reporting. 2. Each group will be given 7 minutes to present. 3. Other learners will listen and evaluate the group.

EVALUATION (10 MINS) Wrap Up: Answer briefly.

I. What happens when there is little sugar in the body? II. What happens when carbon dioxide in the blood increases? 1. What could happen due to a failure in homeostasis? A. The accumulation of waste products B. The loss of excess water from the body C. Maintaining excess levels of sugar in the body D. All of the above are potential outcomes of failure of homeostasis. 2. Which anatomical system of an organism introduces respiratory gases to the interior of the body and enables gas exchange? A. Excretory B. Endocrine C. Respiratory D. None of the above 244

Answer Key:

3. Which organ system alters kidney functions? A. Excretory B. Nervous C. Immune D. Respiratory

1. D 2. C 3. A 4. B 5. C

4. The ___________ systems regulate other organ systems to maintain homeostasis, the maintenance of a stable internal environment. A. digestive and urinary B. nervous and endocrine C. muscular and endocrine D. digestive and respiratory 5. The ______ system regulates the volume of water in the blood and also has an important role in eliminating wastes. A. respiratory B. nervous C. excretory D. endocrine

ENRICHMENT

For Enrichment Part:

Let the learners read the case then accomplish the time line.

This can also be given as an Assignment. The Case Study is taken from: https://msturin.wordpress.com/2010/11/23/ reading-about-homeostasis-in-the-body/ (Last accessed, 04/26/17, 2:57pm)

Assignment:

Teacher Tip:

Research on the range of physiological (sugar level, blood pH, body temperature, pulse rate, breathing rate) conditions for a normal adult (males and females).

Tell the learners that d uring medical checkup or physical examination, the hospital or clinic provides the person a print out of the results. This contains qualitative and quantitative data that may indicate whether a person has an alarming condition.

Case Study Analysis: Josh’s Story

General Biology 2 SUPPLEMENTARY HANDOUTS

HANDOUT A BODY SYSTEM DEBATE

In this project you and your group mates will research on a human body system. Organize a campaign for your body system, present your campaign to the rest of the class, and debate whether or not your body system is most essential to the survival of the human species. In doing this, you will become an “expert” on your body system as well as learn about the other body systems from our classroom “experts”. Once all campaigning and debating is complete, each student will vote for the system that they feel is most essential to humans.

Your campaign must include the following:

1. The name of your body system written clearly. 2. A colored, life-size representation of your body system. 3. A brief description of the overall function(s) of your body system. 4. All organs/parts of your body system drawn on your representation where they are found in nature and clearly labeled. 5. A complete description of the function of each organ/part.

The body system you will be campaigning for is the (check one): 6. A complete description of the importance of your body system to an individual and to the survival of humans referencing • Digestive information given in points 1-5. • Respiratory • Reproductive Your Debate must include the following: • Circulatory • Excretory 1. A review of the importance of your system to the individual and • Lymphatic the species. • Integumentary 2. Rebuttals to points made by each of the other systems. • Nervous 3. Closing arguments. • Skeletal • Endocrine • Muscular

246

CAMPAIGN and DEBATE RUBRIC

CAMPAIGN NA M E O F B O D Y S Y S T E M

CAMPAIGN P OI NT S

DEBATE

DESCRIPTION OF ORGAN OR PART

R E V IE W

P O I NT S

FUNCTION

Written clearly, spelled correctly, easy to see

3

Missing one criterion

2

Missing two criteria Absent

6


1


4

Absent

0

Missing two criteria

2

REBUTTAL

Not all organs and parts accounted for

1

Effectively refutes points made in all other campaigns

15

Absent

0 All other campaigns are refuted, but not all points

10

All other campaigns are not refuted

5

Absent

0

LIFE SIZE REPRESENTATION

Correct size, colored, neatly drawn

12 CONCLUSION


8


4

Absent

0

2

Accurate, clearly stated, easy to understand

1 0

Clearly stated, easy to understand

Clearly stated, easy to understand, evidence to back it up

9


6 CLOSING ARGUMENT

DESCRIPTION OF BODY SYSTEM FUNCTION


3

Accurate, clearly stated, easy to understand

6

Absent

0


4

Missing two criteria Absent

2 0

PLACEMENT AND LABELLING OF ORGANS AND PARTS

All organs and parts are accurately placed and labeled

4

Either not labeled or placed correctly

3

Not all organs and parts accounted for

2

Absent

0

Clearly stated, easy to understand, evidence to back it up

3


2


1

Absent

0

BALLOT

ESSAY RUBRIC

QUESTION: WHY IS THERE NOT ONE SYSTEM WHICH BODY SYSTEM IS MOST ESSENTIAL TO

THAT IS MOST ESSENTIAL TO SURVIVAL OF THE

THE SURVIVAL OF THE HUMAN SPECIES?

HUMAN SPECIES?

Substandard Student shows only a surface level understanding of why there is no one system that is most essential to the survival of the species, and cannot cite examples of this in practice or effectively refute arguments to the contrary.

Nervous System Integumentary System Skeletal System

Adequate Student shows clear but not deep understanding of why there is no one system that is most essential to the survival of the species, cites examples of this in practice, but cannot effectively refute arguments to the contrary.

Muscular System Circulatory System Respiratory System Digestive System

Proficient Student shows clear and deep understanding of why there is no one system that is most essential to the survival of the species, cites examples of this in practice, but cannot effectively refute arguments to the contrary.

Excretory System Endocrine System Reproductive System Lymphatic System

Exemplary Student shows clear and deep understanding of why there is no one system that is most essential to the survival of the species, cites examples of this in practice, and effectively refutes arguments to the contrary. 248

General Biology 2 - Colored Images

Lesson 2: Sex Linkage and Recombination Page 10

Lesson 3: Modification to Mendel’s Classic Ratios Page 18

Lesson 5: DNA Replication and Protein Synthesis Page 26, 27, and 28

Lesson 5: DNA Replication and Protein Synthesis, Page 28

250

Lesson 17.1: Compare and Contrast Process in Plants and Animals: Reproduction and Development Pages 141, 142, and 143

Lesson 17.1: Reproduction and Development / Pages 143 and 145

Lesson 17.2: Reproduction and Development / Pages 150, 151, 152, and 153 252

Lesson 17.2: Reproduction and Development Pa es 15 3, 1 54, and 155

L e s s o n 1 9 : G a s Ex c h a n g e / P a g e 1 8 4

L e s s o n 23 : C he m ic a l a n d N e r v o u s C o n t r o l / P a g e 2 1 7

Lesson 23: Chemical and Nervous Control / Page 218

254

Lesson 23: Chemical and Nervous Control / Page 216

Lesson 17: Introduction to Reproduction / Page 138

Lesson 25: Feedback Mechanisms / Pages 240 and 241

256

Biographical Notes IVAN MARCELO A. DUKA

NEIL ANDREW B. BASCOS, PH.D.

Team Leader

Writer

Prof. Ivan Marcelo A. Duka is an Associate Professor 5 and the College Secretary of the College of Arts and Sciences at the University of the Philippines Los Banos. He has been teaching at the university various courses, such as Biology 1 and 2, Molecular Biology, Evolutionary Biology, Cell Biology and Genetics for 40 years.

Dr. Bascos is an Associate Professor 7 at the National Institute of Molecular Biology and Biotechnology at the University of the Philippines Diliman. He earned his doctorate degree in Molecular and Cellular Biology from Tulane University, New Orleans; and his bachelor’s degree in Molecular Biology and Biotechnology from the University of the Philippines Diliman. He is also a Principal Investigator at the Protein Structure and Immunology Laboratory at the National Institute of Molecular Biology and Biotechnology, UP Diliman. He is a member of the Technical Panel on Biology and Molecular Biology at the Commission on Higher Education, and also became the Deputy Director for Facilities and Services at the National Institute of Molecular Biology and Biotechnology, University of the Philippines Diliman.

He finished his Master of Science in Genetics from the University of the Philippines Los Banos, and his Bachelor’s Degree in Biology, major Apprentice in Zoology, Degree in the same He also earned a Cell Biology from university. the University of Wales College of Cardiff, United Kingdom. He received numerous grants and fellowships, such as the AIDAB Fellowship Award in Sydney, Australia; and the British Council Fellowship to the University of Wales. He also wrote various papers, articles, books, laboratory manuals, and other teaching materials focusing on Biotechnology, Molecular Biology, Immunology, Recombinant DNA Techniques, Physiology, and Genetic Engineering. Prof. Duka is also a Board Member of the Philippine Society for Biochemistry and Molecular Biology, a Subject Matter Specialist of the Learning Resource Centre for Biology Tutorials and Biology Summer Bridge Course, and a member of the UPLB University Council. He is also primarily responsible for assisting incoming university instructors by providing them necessary mentorship in classroom management and curriculum development.

MA. GENALEEN Q. DIAZ, PH.D. Writer

Dr. Genaleen Diaz is Professor IV at the University of the Philippines Los Banos where she has been teaching undergraduate and graduate subjects for 27 years. She is currently the Head of Genetics and Molecular Biology Division of the Institute of Biological Sciences. Dr. Diaz earned her doctorate degree in Genetics at the UPLB. She also completed her master’s degree in Genetics and her bachelor’s degree in Biology at the same university. Dr. Diaz is a member of the National Research Council of the Philippines and the Outstanding Young Scientists, Inc. Her scholarly works were included in publications such as the Philippine Journal of Philippine Science and Technology, Journal of Genetics, and UPLB’s Genetics Laboratory Manual.

MA. CARMINA C MANUEL, PH.D.

IAN KENDRICH C. FONTANILLA, PH.D.

Writer

Writer

Dr. Carmina Manuel is Assistant Professor V at the University of the Philippines Los Banos where she teaches subjects spanning molecular genetics, human genetics, and evolutionary biology. Dr Manuel is recipient of the IBS Outstanding Teacher Award for 3 consecutive years since 2013. She has also presented her authored research papers in Science conferences around the country. Dr. Manuel finished her doctorate degree in Genetics at the UPLB. She earned her master’s degree in Genetics and her bachelor’s degree (cum laude) also in UPLB.

Dr. Ian Fontanilla has been teaching at the University of the Philippines Diliman for 20 years, where he is currently Assistant Professor. His researches are found in scholarly publications, including the Philippine Journal of Science, Asia Life Sciences, and the Zoological Journal of the Linnean Society. Dr. Fontanilla has presented academic papers in international conferences in the Philippines, Portugal, Brazil, Belgium, London, and Australia. He is a member of professional societies such as Unitas Malacologia and the Philippine Environmental Mutagen Society among others. Dr. Fontanilla completed his doctorate in Genetics at the University of Nottingham, while he earned his master’s and bachelor’s degrees in Biology at UP Diliman.

SHARON ROSE M. TABUGO, PH.D. Writer

Dr. Sharon Rose is Assistant Professor IV at the Mindanao State University - Iligan Institute of Technology where she has been teaching for 6 years. Her academic papers and researches were published in a number of ISI-indexed and international journals such as the International Research Journal of Biological Sciences, the European Journal of Zoological Research, the Australian Journal of Biological Sciences, and the Global Journal of Medicinal Plant Research. Dr. Tabugo earned her doctorate degree in Biology at the MSU-IIT. She received her master’s degree in Biology as a DOST scholar also in MSU-IIT and she graduated cum laude with a bachelor’s degree in Biology at the same university.

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EUGENIO P. QUIJANO, JR. Writer

Mr. Eugenio Quijano, Jr. has been teaching science for 25 years now. He is currently a Biology and General Science teacher at the Xavier School and also a student Trainer in science competitions. Prior to teaching, he has worked as a Researcher for the DOST and DepEd. Mr Quijano is a member of the Biology Teachers Association of the Philippines and the Greenpeace Organization. He is currently finishing his master’s degree in Biological Sciences at the University of Santo Tomas. He finished his Certification Program in Education at the University of the Philippines Diliman, and earned his bachelor’s degree in Biology at the UST.

ANNALEE S. HADSALL

CAROLINE PAJARON

Technical Editor

Writer

Prof. Annalee S. Hadsall is an Assistant Professor 7 at the Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Banos. She earned her bachelor’s degree in Biology, Cum Laude, from the Philippine Normal College. She finished her Master of Science degree in Botany, Major in Plant Systematics, and a Minor degree in Horticulture at the University of the Philippines Los Banos, under the UP-NSDB Graduate Manpower Scholarship Program.

Caroline Hernandez Pajaron is a communication specialist and jour nalist. She has 13 yea rs of ex per ie nce in con te nt development, production, and management with different agencies such as Globe Telecommunications, and Asian Development Bank . She is currently Information and Advocacy Officer of the Civil Society Coalition on the Convention on the Rights of the Child. Ms. Pajaron received her master’s degree in Journalism from the Ateneo de Manila University through a Konrad Adenauer Center for Journalism grant. She graduated from the Ateneo as a Father Nicholas Kulny scholar with degrees in English Literature and Communication. She is finishing her doctorate degree in Public Administration at the University of the Philippines.

She is also the curator for orchids and epiphytes at the UPLB Museum of Natural History. Her research interests include morpho-anatomical diversity of indigenous Philippine orchids, biodiversity studies of Mt. Isarog, and phytogeographical patterns of epiphytes. With her work in botany studies, she was able to describe three new plant species, and has written laboratory exercises in biodiversity and general botany. She also a writer in Distance Education Modules for the Diploma in Science Teaching of UP Open University. Besides being prolific in her academic publications, she was also tapped by the Department of Education to evaluate teaching materials and general references in elementary Science. She became a trainer for Grades 8, 9, and 10 Science. She is actively involved in training teachers, especially in biodiversity and plant systematics.

MA. DANIELA LOUISE F. BORRERO

Illustrator

Ms. Daniela Borrero is a visual artist, photographer, writer, and teacher. She is the Founder and Chief Operating Officer of the D11B Graphic Design Studio. She has also worked as Human Resource Officer in a Law Office. Ms. Borrero’s works were part in exhibits such as The Heist Conference and Analog Signals in Nova Gallery, and Maximum Purity in Prose Gallery. She graduated her bachelor’s degree in Home Economics and Elementary Education at the University of the Philippines Diliman.

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