ib_biology_booklet

British School of Brussels vzw

IB Biology Student Handbook Higher and Standard Level (2008 – 2010)

This booklet belongs to: _____________________

Biology Department British School of Brussels vzw

Table of Contents

WHAT WILL YOU STUDY? ................................................................................................................................................ 3 ASSESSMENT POLICY FOR BIOLOGY ........................................................................................................................... 6 HOW WILL THE STUDY OF IB BIOLOGY DIFFER FROM IGCSE?......................................................................... 8 HOW TO BE WELL ORGANIZED DURING YOUR BIOLOGY COURSE:................................................................... 8 CARRYING OUT PRACTICAL WORK SAFELY................................................................................................................ 9 WRITING AN EXPERIMENT REPORT............................................................................................................................11 COPING WITH BIOLOGICAL DRAWINGS...................................................................................................................11 DRAWING TABLES ............................................................................................................................................................ 12 HOW TO DRAW GRAPHS IN BIOLOGY........................................................................................................................ 14 SI UNITS AND HOW TO USE THEM ........................................................................................................................... 15 ERROR ANALYSIS IN BIOLOGY .................................................................................................................................... 17 RECOMMENDED BOOKS FOR A-LEVEL BIOLOGY STUDENTS (REVISED SEPTEMBER 2007) .................... 19 ACTION VERBS ...................................................................................................................................................................22 SOME IMPORTANT POINTS TO REMEMBER.............................................................................................................23 APPENDIX I – BIOLOGY SYLLABUS .............................................................................................................................24 APPENDIX II – SUMMARY OF THE ASSESSMENT SPECIFICATIONS.............................................................58 APPENDIX III: IB INTERNAL ASSESSMENT CRITERIA......................................................................................59 APPENDIX IV – INTERNAL ASSESSMENT CHECKLIST .........................................................................................63

Bio dept/MSc/IB student handbook/august2008 2


What will you study?

Aims of the course It is the aim of all the Diploma Programme experimental science courses and in particular of Biology to: Provide opportunities for scientific study and creativity within a global context that will stimulate and challenge students Provide a body of knowledge, methods and techniques that characterise biology and the biological sciences Enable students to apply and use a body of knowledge, methods and techniques that characterise science and technology Develop an ability to analyse, evaluate and synthesise scientific information Engender an awareness of the need for, and the value of, effective collaboration and communication during scientific activities Develop experimental and investigative skills Develop and apply the students’ information and communication technology skills in the study of science Raise awareness of the moral, ethical, social, economic and environmental implications of using science and technology Develop an appreciation of the possibilities and limitations associated with science and scientists Encourage an understanding of the relationships between scientific disciplines and the overarching nature of the scientific method.

Content The syllabus is delivered in a sequence of topics. There are two options to be studied at both Standard and Higher level. At BSB we have chosen to study Options A: Human Nutrition and Health and G: Ecology and Conservation at Standard level and Options F: Microbes and Biotechnology and Option G: Ecology and Conservation at Higher level. In the appendix at the back of this booklet you will find the syllabus.

Assessment 1. Internal Assessment of written work Internal assessment of theoretical work will occur at teacher discretion. Generally, there will be a short test every two to three weeks. You may also be asked to write essays, carry out research assignments and give short presentations. 2. Internal Assessment of practical work The practical scheme of work (PSOW) is the practical course planned by the teacher and acts as a summary of all the investigative activities you carry out throughout your course. Higher level students are required to spend 60 hours, and Standard level students 40 hours, on practical activities (excluding time spent writing up work). These times include 10 hours for the Group 4 project. The time allocation must be spread out through the course and written evidence of all this work must be kept in a log-file. Students are entirely responsible for their own work and should accept ownership and take pride in the work they complete. The teacher is required to ensure that all the work submitted is the candidate’s own. If in doubt, authenticity may be checked by one or more of the following methods: Discussion with the student Asking the student to explain the methods used and to summarise the results Asking the student to repeat the investigation.

Plagiarism is a serious offence. Always make sure your work is fully referenced following the guidelines you have been given by the school. Failure to do so could result in your work being disqualified.



All the practical work reports will be internally assessed by the teacher using the following five assessment criteria:

Design - D Data collection and processing – DCP Conclusion and evaluation – CE Manipulative skills – MS Personal skills - PS

Each student will be assessed at least twice on each of the first three criteria. Manipulative skills is assessed summatively over the whole course on a wide range of manipulative skills. Personal skills is assessed once only during the Group 4 project. You will find an explanation of these criteria in an appendix at the back of this booklet. It is imperative that you complete this work as it will be submitted to an external moderator and forms part of your final grade. Without the completion of 40 (SL) or 60 (HL) hours of practical work you cannot be awarded your IB Diploma. You must therefore ensure that you attend all practical lessons and inform your teacher of any planned absences. Failure to do this may jeopardise your future in this subject. 3. External Assessment The external assessment consists of three written papers: Paper 1 Paper 1 is made up of multiple-choice questions which test knowledge of the core and additional higher level for higher level (HL) students and the core only for standard level students (SL) students. The questions are designed to be short, one- or two-stage problems. No marks are deducted for incorrect responses. Calculators are not permitted but students are expected to carry out simple calculations. Paper 2 Paper 2 tests knowledge of the core and AHL material for HL students and the core only for SL students. The paper is divided into two sections. In section A, there is a data-based question which will require students to analyse a given set of data. The remainder of section A is made up of short-answer questions. In section B, students are expected to answer two questions from a choice of four at HL or one question from a choice of three at SL. These extended response questions may involve writing a number of paragraphs, solving a substantial problem, or carrying out a substantial piece of analysis or evaluation. A calculator is required for this paper. Paper 3 Paper 3 tests knowledge of the options. At HL, students will answer several short-answer questions and an extended response question in each of the two options studied. At SL, students answer several short-answer questions in each of the two options studied. A calculator is required for this paper.

Field Course The compulsory Ecology work plus the additional Option G require the teaching of a series of skills outside the laboratory and the confines of a restricting timetable. Many of the practicals can only be carried out in the field and on consecutive days. Mountains provide a stimulating and varied environment which is significantly different from that in Belgium; added to which the experience of working as a team is invaluable. The field course takes place in the village of Seix, department of the Ariège (Pyrenees), France during the summer term of Year 12. This fieldtrip is very highly recommended and should be seen as a compulsory element of the course. The approximate cost of the trip is €550. This includes travel, accommodation, meals and tuition for the entire week.



Mathematical requirements You will be taught and expected to have acquired competence in the areas of mathematics set out below in order to develop the knowledge, understanding and skills in the subject content. All Diploma Programme biology students should be able to: Perform the basic arithmetic functions: addition, subtraction, multiplication and division Recognise basic geometric shapes Carry out simple calculations within a biological context involving means, decimals, fractions, percentages, ratios, approximations, reciprocals and scaling Use standard notation (e.g. 3.6 x 106) Use direct and inverse proportion Represent and interpret frequency data in the form of bar charts, column graphs and histograms, and interpret pie charts and nomograms Determine the mode and median of a set of data Plot and interpret graphs (with suitable scales and axes) involving two variables which show linear or nonlinear relationships Plot and interpret scatter graphs to identify a correlation between two variables, and appreciate that the existence of a correlation does not establish a causal relationship Demonstrate sufficient knowledge of probability to understand how Mendelian ratios arise and to calculate such ratios using a Punnett grid Make approximations of numerical expressions Recognise and use the relationships between length, surface area and volume.



Assessment Policy for Biology Internal assessment consists of assessed practical work carried out in the laboratory or field during lesson time and field trip. There is also a joint project to be completed by all IB students – Group 4 project. Students are expected to carefully read the comments made by the teacher during the marking of the assessed practicals. They may also discuss their performance with the teacher and seek advice on how to improve. This should result in a better mark for their subsequent piece of work for that skill. The students will be informed at the start of the course of the criteria for assessment and will be provided with a copy of these criteria. Appropriate assessment tasks are: • • • • • •

The assessed practical work Interim tests End of unit topic tests Essays Homework tasks Presentations

Student work should be graded using: • • •

The internal assessment (IA) criteria A comment or mark (e.g. 15/20) for homework and short class work assignments The IB grading system – grades 1-7, as follows: 7 6 5 4 3 2 1

Excellent performance Very good performance Good performance Satisfactory performance Mediocre performance Poor performance Very poor performance

Where more than one teacher is involved in the assessment of a group of students, moderation should occur to ensure consistency and equality across the department. Sanctions for missing work deadlines: (taken from the BSB International Baccalaureate Assessment Policy) •

•

•

Teachers will be responsible for ensuring that students complete homework tasks set and will follow up with appropriate sanctions, this will include extension of deadline, requesting the student returns to complete work at a time arranged by the teacher, lunchtime detention. For repeat offenders an after school detention may be appropriate, to be organised through HOD. Teachers will be responsible for ensuring that students complete internal assessment tasks set and will follow up with appropriate sanctions, this will include extension of deadline to next day and a lunchtime detention if not completed to allow the student the chance to complete the work, referral to IB coordinator. The IB coordinator will set a new deadline and impose after school detentions in order for the student to complete the work.

Timeline for assessment: • •

Internal assessment practicals will be completed during lessons (approximately one per week for Higher level students and one every two weeks for Standard level students) The practicals will be written up during the lesson and completed for homework and form an integral part of the homework load for the subject.



• • •

The teacher will keep the assessed practicals in the student’s individual portfolio, in the department. Students may consult this in school under supervision of the teacher. End of unit topic tests and interim tests will be set at a convenient time to be arranged after discussion with the students. Tests will be marked and returned to the students in the shortest possible time. Essays and homework tasks will be set taking into account the allocated load for the subject and the practical write-ups.



How will the study of IB Biology differ from IGCSE? A lot! The workload is much greater and the time you put into it is open-ended. We recommend a minimum of 4 hours homework for higher level per week and 3 hours for standard level per week. We expect you to be self-motivated e.g. if we set you only 2 hours homework one week, you should make up the total hours with background reading or revision. Classes are smaller and you are treated as adults. You will be among other students who chose to study Biology; so learning becomes more stimulating. The work you do will differ from GCSE in many ways: topics are covered in greater depth some topics will be completely new to you you will learn to research from books, journals and the internet and to write essays from your notes you will be assigned your own microscope your biological drawing skills will improve you will carry out practical work requiring a high level of skill and precision you will do field work How to be well organized during your Biology course: Attend all the lessons and if you do miss any make sure you catch up with the work immediately. Ask your teacher to tell you what you missed. Do not miss practical lessons. Ensure you are on time for lessons and prepared to take an active role in class. If you don’t understand something … ASK FOR HELP. Make notes, when appropriate, during lessons. Ensure you write your own notes and read up about the topics taught before the next lesson. Keep all loose pages in the A4 folder provided. It is your responsibility to keep the notes tidy and in good order and to submit them to a member of staff for checking if requested. Put all loose pages together at the end of a topic, including notes, keyword lists, exercises, revision notes, experimental write-ups and tests. Keep up to date with your written assignments. Don’t let the work pile up and ensure you meet deadlines. If for a good reason you cannot meet a deadline, let your teacher know in advance. Read your textbooks. Answer plenty of practice questions. Get into the habit of visiting the school library and use your study periods to read additional books and make notes. This is a great way of preparing for the type of work you will be doing at university. Read at least a few of the books from the recommended reading list. You will find them in the school library. Revise thoroughly for topic and unit tests. This will help you keep up with the work and will ensure you make consistent progress. If you would like to do any additional work, such as microscope work, other practicals, etc. discuss this with your teacher. It may be possible for you to work under supervision during your study periods and/or lunchtime.



Carrying out practical work safely Follow these simple rules to work safely in the laboratory: Familiarise yourself with the fire safety procedures for the laboratory. Know where the emergency exit(s) is (are) and ensure you know how to raise the alarm in the event of fire. Always move slowly around the laboratory. Wear a protective lab coat and goggles where necessary. 1 Tie long hair back and do not wear dangly necklaces and earrings. Never eat or drink in the laboratory. Tuck your bags and other personal items safely under the bench before you begin. Never place your fingers in your mouth or eyes after using chemicals or touching biological specimens. Read the practical protocol carefully before you start, and ensure that you are clear about what you are going to do. Pay particular attention to specific hazards associated with any of the substances involved in the practical. Carefully read the warning labels on reagent bottles. When planning practical work, you should always carry out a risk assessment, which must be checked by your teacher before you start to do the work. Make sure that fragile objects such as glassware are placed where they cannot be knocked over or rolled off the bench. If you break any glass dispose of it in the container reserved specifically for this purpose. Allow hot objects such as Bunsen burners, tripod, gauze and beakers to cool down before you handle them. Wipe up any spillages with paper towels and dispose of in a bin. Spillages of cultures of micro organisms should be treated as hazardous and disposed of in autoclavable bags. If you are not sure how to do something, ask for help. When you have completed your work, clear away all apparatus and leave the bench clean and tidy. Do not remove eye protection until everyone else has finished. If there is an accident or breakage it must be reported to the member of staff. Additional recommendations for practical work involving micro organisms: Eating, drinking, chewing, licking labels, applying make-up, chewing pens or pencils, and mouth pipetting are forbidden in any laboratory when handling microorganisms. Any exposed cuts or broken skin must be covered with a waterproof dressing before undertaking any practical work involving microorganisms. Before you start the practical work, wipe the surface of the bench with a suitable disinfectant. Bacteriological wire loops should be no more than 5cm long and must be closed. Wire loops must be sterilized by heating the wire, held almost vertically, in a Bunsen flame until the wire is red-hot. When resterilising the loop after use, introduce the loop slowly into the flame to prevent spattering. Allow the loop to cool for about 10 seconds, without coming into contact with a surface, before use. Discard jars containing fresh disinfectant are available at each workstation for disposal of contaminated items. Flame the neck of a bottle by passing the opening through a Bunsen flame, before pouring. Lids, caps, or cotton wool plugs should be held using the little finger of the other hand – they must not be placed on the bench. Flame the neck of the bottle again before replacing the top. After inoculating an agar plate, the Petri dish lid should be secured with adhesive tape. Use two or three pieces of tape to fasten the lid, but do not seal all the way round as this could create anaerobic conditions and encourage the growth of possible pathogenic microorganisms. The recommended maximum temperature for incubation of cultures is 30°C. Cultures should not be incubated at 37°C, as this is an ideal temperature for the growth of many human pathogenic species. Agar plates should be incubated in an inverted position, with the agar uppermost, as this allows condensation to collect on the lid. Do not open Petri dishes after incubation. All bacterial or fungal cultures must be sterilized by autoclaving at 121°C for 15 minutes before disposal. Use the appropriate biohazard autoclavable plastic bags for this purpose, left open in the autoclave so steam can penetrate. When you have finished your practical work, wipe the bench with disinfectant; wash your hands with soap and dry using disposable paper towels before leaving the laboratory. 1

You are expected to provide your own lab coat for practical work. You may use the same lab coat for Biology and Chemistry but you must remember to bring it to lessons. You should ensure you take it home to wash regularly. For Microbiology practical work you will use a lab coat provided by the school, which does not leave the lab. Bio dept/MSc/IB student handbook/august2008 9


If spillage of a culture occurs, it should be dealt with as follows: Disposable gloves must be worn and the broken container and/or spilled culture covered with a cloth soaked in disinfectant and left for at least 10 minutes. The materials should then be cleared away with paper towels and a dustpan, which should then be placed in a disposable bag and autoclaved.



Writing an Experiment Report Each practical that you carry out will need to be written-up. At the back of this booklet you will find an appendix (Appendix IV) with some help sheets. You should always refer to these when writing the reports of your practicals. You must also make yourself familiar with the criteria for practical assessment which are included in this booklet (Appendix III) for your information.

Coping with biological drawings Biological drawings can be made from biological specimens viewed with a microscope, binocular microscope or hand-lens. They should always be accurate records of the observed features of a specimen. The most informative drawings are not necessarily the most ‘artistic’ and in Biology we avoid shading as this obscures scientific detail. A drawing is different from a diagram. Whilst a drawing is an accurate record of your observations of a particular biological specimen, showing only the features that can be seen clearly, a diagram is a more stylized representation of a structure. In a diagram, it is customary to include all the essential features known to be associated with the specimen, whether visible or not. Drawing (made from biological specimens viewed with a microscope) Use a clean piece of white, unlined A4 paper Use clear pencil lines, preferably using a medium pencil (HB). Make sure that your drawing fills up at least half the sheet of paper and is large enough to show all the relevant features. Look at the specimen carefully before you start and try to get the proportions right – if you take time here it is easy to fill in more details later. Draw a clean, clear outline. Add some of the other features that you can see. Add straight labelling lines using a ruler. Label the features well. Annotate the drawings (not separate notes underneath). Annotate points of particular biological interest relevant to the aims of the investigation e.g. do not annotate all functions of the nucleus on a drawing showing striations on a muscle fibre, simply label it). Add a scale so that you can give some idea of size (e.g. viewed at x 100) Add a title that describes the specimen that you have drawn. State whether it is a whole specimen, a whole mount, a T.S., a L.S., etc. When drawing low power plans do not draw individual cells. Show only the distribution of tissues. When making high power drawings, draw only a few representative cells; indicate thickness of walls, membranes, etc. Do not use shading but show granular nature of cytoplasm, striation in muscle, etc. Do not copy textbook drawings. They are often diagrams!



Drawing tables 2

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Images taken from: The Open Door Website © Paul Billiet 2003


How to draw graphs in Biology In Biology you will draw all kinds of graph, including bar charts, pie graphs and line graphs. Choosing which type of graph to draw can be tricky. Here are some pointers: Use a pie chart if you want to make simple comparisons visually attractive. These are rarely very good for experimental results. Use a bar chart if one of your variables has just a few discrete values (e.g. colours, gender, types of material) but the other variable is continuous. Use a line graph if both of your variables are continuous (e.g. temperature, mass, length, etc.). Plotting graphs by hand In order to draw an accurate graph you need to remember the following points: Use a sharp pencil and a ruler. Label the axes with quantity and unit (e.g. time/minutes). The scale on each axis must use up at least half of the graph paper When drawing line graphs, plot your points using crosses (x) Do not draw best-fit lines for Biology. Join the point “dot-to-dot” with a straight line (use a ruler)! The point must be no further than half the smallest square on your graph paper from the correct place or you will lose marks. When plotting graphs of your experimental results, it is a good idea to use a computer to quickly plot a graph enabling you to find out what is happening. If necessary, you can repeat an experiment or try out further ideas. However, computer-drawn graphs are not very accurate unless you are an expert in the use of computer packages; and even these will take a long time to draw an accurate graph. Using Excel to plot graphs

Use Excel. For line graphs, use the ‘scatter graph’ function. Allow the computer to join the points or join them by hand Change the minimum and maximum values of the graph if necessary. Make sure your graph is big – at least half a side of A4. Use the information provided by your teacher at the start of the course

Graph checklist: 1. Use graph paper. 2. Use pencil and ruler. 3. Make sure your graph is a good size. 4. Draw in the two axes with a ruler. 5. Put the independent variable on the horizontal axis. 6. Scales on each axis should go up evenly (but do not necessarily have to start at zero). 7. Scales increase upwards and from left to right. 8. Adjust the scale to fit the range of data (so that it covers the highest and lowest value). 9. Give your graph a title which explains what it is about (try to include the variables). 10. Plot the points accurately with a small ‘x’ or a dot. 11. Label both axes with the name of the variable and the units (use abbreviations for scientific units). 12. Use a key with plotting symbols if you plot several lines.


SI units and how to use them 3

When you make quantitative observations you are expected to use the appropriate units. The system of units used is the International System of Units - SI units (Système International d’Unités). In the table below you are given some of the more common SI units you will need to use. Name Mass Length Time Area Volume Concentration

Unit kilogram metre second square metre cubic decimetre moles per cubic decimetre Pascal joule

Pressure Energy

Symbol Kg m s m² dm³ -3 mol dm Pa J

When showing length, it is acceptable to use the associated units shown in the table below. Unit name kilometre metre centimetre millimetre micrometre nanometre

Multiple or fraction of a metre 10³ -2

10 10 -3 -6 10 10 -9

Symbol km m cm mm μm nm

When measuring time, it is acceptable to use minutes, days or hours when the experiment spans over a significant period of time.

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Adapted from Morgan, Sally (2002) Advanced Level Practical Work for Biology. Hodder & Stoughton.



In the table below you are given some of the rules concerning the correct use of SI units. Rule Abbreviations such as sec, cc or mps should be avoided. Only use standard unit symbols, prefix symbols, unit names and prefix names Unit symbols are unaltered in the plural Unit symbols are not followed by a full stop unless at the end of a sentence Information should not be mixed with unit symbols or names It must be clear to which unit symbol a numerical value belongs Unit symbols and unit names must not be mixed

The word ‘weight’ is often used interchangeably with the term ‘mass’. In science, weight is a force and the SI unit is the Newton. The SI unit for mass is the kilogram The term molarity, with the symbol M, is no longer used. Instead the concentration should be expressed as moles per cubic decimetre

Correct use s or second cm³ or cubic centimetre m/s, ms -1 or metre per second

sec cc mps

Incorrect use

25 cm

25 cms

The length of the leaf is 15 cm. The leaf is 15 cm long.

The leaf is 15 cm. long.

The biomass of grass was 544 g/m². 21 cm x 39 cm 20°C to 30°C or (20 to 30)°C 101 g ± 3 g or (101 ± 3) g 74% ± 6% or (74 ± 6) % kg/m³ -3 kg m kilogram per cubic metre

544 g of grass /m²

The mass of grass is 100 g.

21 x 39 cm 20°C – 30°C or 20 to 30°C 101 ± 3 g 74 ± 6 % kilogram/m³ kg/cubic metre kilogram/cubic metre kg per m³ kilogram per metre³ The weight of grass is 100 g.

0.2 mol dm -3

0.2M



Error Analysis in Biology 4 Error analysis in Biology is no different from that in other sciences. Biology however is not an “exact” science in that much of the data collected by biologists is qualitative. Furthermore, biological systems are very complex and difficult to control. Biological investigations, nevertheless, do often require measurements and biologists do need to be aware of the sources of error in their data. Human error Obviously data that is carefully recorded will be more reliable than data collected carelessly. Human error can occur when tools or instruments are used to read incorrectly. For example, a temperature reading from a thermometer in a liquid should be taken after stirring the liquid and whilst the bulb of the thermometer is still in the liquid. Thermometers and other instruments should be read with the eye level with the liquid otherwise this results in parallax error. Human errors can be systematic because the experimenter does not know how to use the apparatus properly or they can be random because the power of concentration of the experimenter is fading. Systematic error If an electronic water bath is set to 37°C the thermometer in the water bath should also read 37°C. If they do not agree then there will be an error at any other temperature being used. Some instruments need calibrating before you use them. If this is done correctly and regularly it can reduce the risk of systematic error. Random errors In biological investigations, the changes in the material used or the conditions in which they are carried can cause a lot of errors. For example the rate of transpiration of a small animal measured using a manometric respirometer can be influenced by changes in air temperature and barometric pressure. Biological material is notably variable. For example, the water potential of potato tissue may be calculated by soaking pieces of tissue in a range of concentrations of sucrose solutions. However, different pieces of tissue will vary in their water potential especially if they have been taken from different potatoes. The problem of random errors can be kept to a minimum by careful selection of material and careful control of variables (e.g. using a water bath or a blank). As we saw above, human errors can become random when you have to make a lot of tedious measurements, your concentration span can vary. Automated measuring using a data-logger system can help reduce the likelihood of this error; alternatively you can take a break from measuring from time to time.

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Taken from: The Open Door Website, © Paul Billiet 2003



Replicates and samples Because of their complexity and variability biological systems require replicate observations and multiple samples of material. As a rule the lower limit is 5 measurements or a sample size of 5. Very small samples run from 5 to 20, small samples from 20 to 30 and big samples above 30. Selecting data Replicates permit you to see if data is consistent. If a reading is very different from the others it may be left out from the processing and analysis. However, you must always be ready to justify why you did this. Degrees of precision If you use a ruler, graduated in millimetres, to measure an object (e.g. the length of a leaf) you will probably find the edges of the object lie close to a millimetre division but probably not right on it. Recording the leaf as “4.5cm-and-a-bit” is not very useful. The accepted rule is that the degree of precision is ± the smallest division on the instrument, in this case one millimetre. So the leaf in this example is 4.5cm±0.1cm. The degree of precision will influence the instrument that you choose to make a measurement. For example, if you used the same ruler to measure an object 0.5cm long the degree of precision (±0.1cm) is 20% of the measurement. This is a very large error margin and, so, it is not very precise. Therefore, we must choose an appropriate instrument for measuring a particular length, volume, pH, light intensity, etc. The act of measuring When a measurement is taken this can affect the environment of the experiment. For example when a cold thermometer is put in a test tube of warm water, the water will be cooled by the presence of the thermometer. When the behaviour of animals is being recorded the presence of the experimenter may influence them.

Why bother? You might think that all these sources of error and imprecision make experimental results worthless. This is not true, it is understood that experimental results are only estimates. What is expected of a scientist is that they: (i) make the best effort to avoid errors in their design of investigations and the use of instruments, and (ii) are aware of the possible source of errors and appreciate their magnitude.



Recommended books for A-level Biology Students (revised September 2007) Most of these books and many others are in the school library. If you cannot find them there but would like to read the books talk to Maria. Dawkins, Richard (2006), The God Delusion, Bantam Press (ISBN 978-0593055489) Economist 'Everyone should read it. Atheists will love Mr. Dawkins's incisive logic and rapier wit...' Dawkins, Richard (1989), The Selfish Gene, Oxford University Press (ISBN 0-19-286092-5) Has been re-printed many times. An absolute must! This is recommended reading by the Oxbridge biological and natural sciences tutors. Dawkins, Richard (1986), The Blind Watchmaker, Penguin (ISBN 0-14-014484-1) Several reprints. See above. Ridley, Matt (1994), The Red Queen – Sex and the Evolution of Human Nature, Penguin. (ISBN 0-14-016772-2) Matt Ridley is an Oxford graduate who has become a science journalist and has won several international prizes with his “popular science” books. Some original ideas and well-argued cases make him a compulsory read. Ridley, Matt (1999), Genome – The Autobiography of a species in 23 chapters, Fourth Estate. (ISBN 1-85702-835-X) A tour through the human genome. Ridley, Matt (2003), Nature via nurture – genes, experience and what makes us human, Fourth Estate. (ISBN 1-84115-745-7) ‘A real page-turner. What a superb writer he is, and he seems to get better and better.’ Richard Dawkins, author of The Selfish Gene. Ridley, Matt (2003), Evolution (Oxford Readers), Oxford University Press. (ISBN 978-0199267941) First Sentence The mail delivery of 17 June 1858 at Down House, Kent, England, is one reasonable starting-date for the literature of evolution. Jones, Steve (2002), Y- The Descent of Men, Little, Brown. (ISBN 0-316-85615-0) Winner of the BP Natural World Book Prize. “This book is great … you simply can’t put it down”, New Scientist. Jones, Steve (2007), Coral: A Pessimist in Paradise, Little, Brown. (ISBN 978-0316729383) THE ECONOMIST `Jones is an experienced, poetic pilot, steering an eccentric and surprising course through the intricacies of reef life'. GUARDIAN 'One of science's best writers' Broomhall, Clive (2003), The Eternal Child – An Explosive New Theory of Human Origins and Behaviour, Ebury Press. Bio dept/MSc/IB student handbook/august2008 19


(ISBN 009188574-4) A revolutionary new theory of our origins and the roots of modern human behaviour. Giddings, G., Jones, N. and Karp, A. (2001), The Essentials of Genetics (Advanced Biology Readers), Hodder Murray (ISBN 978-0719586118) Designed for students of A level biology, this text introduces the subject of genetics by looking at how characteristics are passed from one generation to another and the processes that lead to variation within a species. Gibb, Barry (2007), The Rough Guide to the Brain, Rough Guides, Ltd. (ISBN 978-1843536642) Within our skulls resides an organ more powerful than the fastest supercomputer, the ultimate multi-tasker controlling everything from the retrieval of memories to complex reasoning - and even breathing. "The Rough Guide to the Brain" provides an absorbing and accessible introduction to the science of the mind - from how the human brain evolved over millions of years and how it differs from those of other animals to the power of positive thinking and extrasensory perception hypnosis. Leroi, Armand Marie (2004), Mutants: On the form, varieties and errors of the human body, Harper Collins. (ISBN 0002571137) Matt Ridley, Author of Genome '...Armand Leroi combines meticulous historical research, brand-new genetic understanding and consummate skill with words to tell an absorbing tale' Sims, Michael (2003), Adam’s Navel- A Natural and Cultural History of the Body, Penguin. (ISBN 0713995688) In this title Michael Sims simultaneously explores the natural history of the body and the cultural history that records our response to it. Divided into sections corresponding with various body parts, this almanac explores every aspect of the human form - from the largest organ (the skin) to the evolutionary reasoning behind sexually attractive body parts - witness the cult of aprodite kalipygos ("the goddess with the beautiful buttocks"). Sykes, Brian (2002), The Seven Daughter’s of Eve, Corgi. (ISBN 0552148768) In The Seven Daughters of Eve Bryan Sykes has produced a highly readable scientific autobiography depicting the major events in his career as a human geneticist. He was the first to extract DNA from the bones of the 5,000-yearold Iceman, and he solved the problem of the colonisation of Polynesia by tracing modern Polynesians' genetic ancestry. The high point of his work so far is the creation of a genetic map of Western Europe, showing that over 95% of native Europeans can trace their ancestry back to one of seven individual women. Gribbin, John (2002), Science – A history 1543-2001, Allen Lane/Penguin. (ISBN 0-713-995-033) If you are or aspire to be a scientist this is an excellent reference book for your library. You will read the chapters that interest you most and then find yourself wanting to read the rest. Lane, Nick (2006), Power, Sex, Suicide: Mitochondria and the Meaning of Life, Oxford University Press. (ISBN 978-0199205646) Biologist, October 1, 2006 An enthralling account. The author has accomplished something quite breathtaking. Crawford, Dorothy H. (2000), The Invisible Enemy – A natural history of viruses, Oxford University Press.



(ISBN 0-19-856481-3) “This fascinating book provides a rapid and accessible introduction to modern virology”, NATURE. Noble, Denis (2006), The Music of Life: Biology beyond the genome, Oxford University Press (ISBN 978-0199295739) What is Life? Decades of research have resulted in the full mapping of the human genome - three billion pairs of code whose functions are only now being understood. The gene's eye view of life, advocated by evolutionary biology, sees living bodies as mere vehicles for the replication of the genetic codes. But for a physiologist, working with the living organism, the view is a very different one. Ellison, Peter T. (2001), On Fertile Ground – A Natural History of Human Reproduction, Harvard University Press. (ISBN 0-674-01112-0) “Anyone interested in the study of reproduction … will enjoy reading this book.”, Michael Grimes, American Journal of Human Biology. Ashcroft, Frances (2001), Life at the Extremes, Flamingo. (ISBN 0006551254) “This is so fascinating everybody will want to take Frances Ashcroft’s physiology course at Oxford!”.



Action verbs Analyse

interpret data to reach conclusions

Annotate

add brief notes to a diagram, drawing or graph

Apply

use an idea, equation, principle, theory or law in a new situation

Calculate

find an answer using mathematical methods (show the working unless instructed not to do so)

Compare

give an account of similarities and differences between two (or more) items, referring to both (all) of them throughout (comparisons can be given using a table)

Construct

represent or develop in graphical form

Deduce

reach a conclusion from the information given

Define

give the precise meaning of a word or phrase as concisely as possible

Derive

manipulate a mathematical equation to give a new equation or result

Describe

give a detailed account, including all the relevant information

Design

produce a plan, object, simulation or model

Determine

find the only possible answer

Discuss

give an account including, where possible, a range of arguments, assessments of the relative importance of various factors or comparisons of alternative hypotheses

Distinguish

give the differences between two or more different items

Draw

represent by means of pencil lines (add labels unless told not to do so)

Estimate

find an approximate value for an unknown quantity, based on the information provided and scientific knowledge

Evaluate

assess the implications and limitations

Explain

give a clear account including causes, reasons and mechanisms

Identify

find an answer from a number of possibilities

List

give a sequence of names or other brief answers with no elaboration, each one clearly separated from the others

Measure

find a value for a quantity

Outline

give a brief account or summary (include essential information only)

Predict

give an expected result

Solve

obtain an answer using algebraic and/or numerical methods

State

give a specific name, value or other brief answer (no supporting argument or calculation is necessary)

Suggest

propose a hypothesis or other possible answer

Exam Tip: If you know the meanings of all the command terms, then you know what the examiners expect you to do. Pay attention to the number of marks available for that question and make at least that many relevant points.



Some important points to remember Here are some of the most important points to remember if you want to guarantee your success: Get into a routine straight away and stick to it – write out a homework timetable and adhere to it Use your syllabus – check off topics as we cover them, make sure you know what we’re looking for in your coursework; be aware of what is coming up next and prepare for it READ! We can’t stress this enough. Read your textbook, the recommended biological literature, the excellent reference and resource books in the library, Biological Science Review, etc. Use the Internet for some additional research and for the fantastic images and animations. Use recommended sites on the Internet but… remember there are also some very poor websites with misleading and incorrect information. All of this can make the difference between one grade and another. It also greatly increases your understanding and enjoyment of the subject. Constant revision is essential if you are to succeed in a modular course: don’t leave it to the last moment. IB requires much more remembering than GCSE. You will be tested frequently to make sure you keep up to standard. If you stop enjoying Biology it’s probably because you’re no longer keeping up. Don’t let things slip – do something about it before it’s too late. Don’t just come to lessons – if you need additional help let your teachers know. Use the Biology Department as much as possible and talk to us if you have problems: we’re here to help.

Tracking your progress through the syllabus: o As you cover an assessment statement in class or as part of an assignment, highlight it with a marker and tick the ‘done in class’ box o Once you have revised the work, put a tick under ‘revised at home’ o If you are 100% sure that you could walk into the exam and answer a question on that statement (remember the command verb), stick a smiley face under ‘I’m confident’ o It’s a visual way to track you progress. Have a go…


Appendix I – Biology Syllabus Topic 1: Statistical analysis (2 hours) Assessment statement 1.1.1

State that error bars are a graphical representation of the variability of data.

1.1.2

Calculate the mean and standard deviation of a set of values.

1.1.3

State that the term standard deviation is used to summarize the spread of values around the mean, and that 68% of the values fall within one standard deviation of the mean.

1.1.4

Explain how the standard deviation is useful for comparing the means and the spread of data between two or more samples.

1.1.5

Deduce the significance of the difference between two sets of data using calculated values for t and the appropriate tables.

1.1.6

Explain that the existence of a correlation does not establish that there is a causal relationship between two variables.

Topic 2: Cells (12 hours) Assessment statement 2.1

Cell theory.

2.1.1

Outline the cell theory.

2.1.2

Discuss the evidence for the cell theory.

2.1.3

State that unicellular organisms carry out all the functions of life.

2.1.4

Compare the relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using the appropriate SI unit.

2.1.5

Calculate the linear magnification of drawings and the actual size of specimens in images of known magnification.

Done in class Revised at home

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2.1.6

Explain the importance of the surface area to volume ratio as a factor limiting cell size.

2.1.7

State that multicellular organisms show emergent properties.

2.1.8

Explain that cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others.

2.1.9

State that stem cells retain the capacity to divide and have the ability to differentiate along different pathways.

2.1.10

Outline one therapeutic use of stem cells. Assessment statement

2.2

Prokaryotic cells

2.2.1

Draw and label a diagram of the ultra structure of Escherichia coli (E. coli) as an example of a prokaryote.

2.2.2

Annotate the diagram from 2.2.1 with the functions of each named structure.

2.2.3

Identify structures from 2.2.1 in electron micrographs of E. coli.

2.2.4

State that prokaryotic cells divide by binary fission. Assessment statement

2.3

Eukaryotic cells

2.3.1

Draw and label a diagram of the ultra structure of a liver cell as an example of an animal cell.

2.3.2

Annotate the diagram from 2.3.1 with the functions of each named structure.

2.3.3

Identify structures from 2.3.1 in electron micrographs of liver cells.

2.3.4

Compare prokaryotic and eukaryotic cells.

2.3.5

State three differences between plant and animal cells.

2.3.6

Outline two roles of extra cellular components.



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Assessment statement 2.4

Membranes

2.4.1

Draw and label a diagram to show the structure of membranes.

2.4.2

Explain how the hydrophobic and hydrophilic properties of phospholipids help to maintain the structure of cell membranes.

2.4.3

List the functions of membrane proteins.

2.4.4

Define diffusion and osmosis.

2.4.5

Explain passive transport across membranes by simple diffusion and facilitated diffusion.

2.4.6

Explain the role of protein pumps and ATP in active transport across membranes.

2.4.7

Explain how vesicles are used to transport materials within a cell between the rough endoplasmic reticulum, Golgi apparatus and plasma membrane.

2.4.8

Describe how the fluidity of the membrane allows it to change shape, break and re-form during endocytosis and exocytosis. Assessment statement

2.5

Cell division

2.5.1

Outline the stages in the cell cycle, including interphase (G1, S, G2), mitosis and cytokinesis.

2.5.2

State that tumours (cancers) are the result of uncontrolled cell division and that these can occur in any organ or tissue.

2.5.3

State that interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts.

2.5.4

Describe the events that occur in the four phases of mitosis (prophase, metaphase, anaphase and telophase).



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2.5.5

Explain how mitosis produces two genetically identical nuclei.

2.5.6

State that growth, embryonic development, tissue repair and asexual reproduction involve mitosis.

Topic 3: The chemistry of life (15 hours) Assessment statement 3.1

Chemical elements and water

3.1.1

State that the most frequently occurring chemical elements in living things are carbon, hydrogen, oxygen and nitrogen.

3.1.2

State that a variety of other elements are needed by living organisms, including sulphur, calcium, phosphorus, iron and sodium.

3.1.3

State one role for each of the elements mentioned in 3.1.2.

3.1.4

Draw and label a diagram showing the structure of water molecules to show their polarity and hydrogen bond formation.

3.1.5

Outline the thermal, cohesive and solvent properties of water.

3.1.6

Explain the relationship between the properties of water and its uses in living organisms as a coolant, medium for metabolic reactions and transport medium. Assessment statement

3.2

Carbohydrates, lipids and proteins

3.2.1

Distinguish between organic and inorganic compounds.

3.2.2

Identify amino acids, glucose, ribose and fatty acids from diagrams showing their structure.

3.2.3

List three examples each of monosaccharides, disaccharides and polysaccharides.

3.2.4

State one function of glucose, lactose and glycogen in animals, and of fructose, sucrose and cellulose in plants.

3.2.5

Outline the role of condensation and hydrolysis in the relationships between monosaccharides,



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disaccharides and polysaccharides; between fatty acids, glycerol and triglycerides; and between amino acids and polypeptides. 3.2.6

State three functions of lipids.

3.2.7

Compare the use of carbohydrates and lipids in energy storage. Assessment statement

3.3

DNA structure

3.3.1

Outline DNA nucleotide structure in terms of sugar (deoxyribose), base and phosphate.

3.3.2

State the names of the four bases in DNA.

3.3.3

Outline how DNA nucleotides are linked together by covalent bonds into a single strand.

3.3.4

Explain how a DNA double helix is formed using complementary base pairing and hydrogen bonds.

3.3.5

Draw and label a simple diagram of the molecular structure of DNA. Assessment statement

3.4

DNA replication

3.4.1

Explain DNA replication in terms of unwinding the double helix and separation of the strands by helicase, followed by formation of the new complementary strands by DNA polymerase.

3.4.2

Explain the significance of complementary base pairing in the conservation of the base sequence of DNA.

3.4.3

State that DNA replication is semi-conservative.



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Transcription and translation

3.5.1

Compare the structure of RNA and DNA.

3.5.2

Outline DNA transcription in terms of the formation of an RNA strand complementary to the DNA strand by RNA polymerase.

3.5.3

Describe the genetic code in terms of codons composed of triplets of bases.

3.5.4

Explain the process of translation, leading to polypeptide formation.

3.5.5

Discuss the relationship between one gene and one polypeptide. Assessment statement

3.6

Enzymes

3.6.1

Define enzyme and active site.

3.6.2

Explain enzyme–substrate specificity.

3.6.3

Explain the effects of temperature, pH and substrate concentration on enzyme activity.

3.6.4

Define denaturation.

3.6.5

Explain the use of lactase in the production of lactose-free milk. Assessment statement

3.7

Cell respiration

3.7.1

Define cell respiration.

3.7.2

State that, in cell respiration, glucose in the cytoplasm is broken down by glycolysis into pyruvate, with a small yield of ATP.

3.7.3

Explain that, during anaerobic cell respiration, pyruvate can be converted in the cytoplasm into lactate,



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or ethanol and carbon dioxide, with no further yield of ATP. 3.7.4

Explain that, during aerobic cell respiration, pyruvate can be broken down in the mitochondrion into carbon dioxide and water with a large yield of ATP. Assessment statement

3.8

Photosynthesis

3.8.1

State that photosynthesis involves the conversion of light energy into chemical energy.

3.8.2

State that light from the Sun is composed of a range of wavelengths (colours).

3.8.3

State that chlorophyll is the main photosynthetic pigment.

3.8.4

Outline the differences in absorption of red, blue and green light by chlorophyll.

3.8.5

State that light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen.

3.8.6

State that ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules.

3.8.7

Explain that the rate of photosynthesis can be measured directly by the production of oxygen or the uptake of carbon dioxide, or indirectly by an increase in biomass.

3.8.8

Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis.


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Topic 4: Genetics (15 hours) Assessment statement 4.1

Chromosomes, genes, alleles and mutations

4.1.1

State that eukaryote chromosomes are made of DNA and proteins.

4.1.2

Define gene, allele and genome.



4.1.3

Define gene mutation.

4.1.4

Explain the consequence of a base substitution mutation in relation to the processes of transcription and translation, using the example of sickle-cell anaemia. Assessment statement

4.2

Meiosis

4.2.1

State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei.

4.2.2

Define homologous chromosomes.

4.2.3

Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells.

4.2.4

Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21).

4.2.5

State that, in karyotyping, chromosomes are arranged in pairs according to their size and structure.

4.2.6

State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities.

4.2.7

Analyse a human karyotype to determine gender and whether non-disjunction has occurred. Assessment statement

4.3

Theoretical genetics

4.3.1

Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus, homozygous, heterozygous, carrier and test cross.

4.3.2

Determine the genotypes and phenotypes of the offspring of a monohybrid cross using a Punnett grid.

4.3.3

State that some genes have more than two alleles (multiple alleles).

4.3.4

Describe ABO blood groups as an example of codominance and multiple alleles.

4.3.5

Explain how the sex chromosomes control gender by referring to the inheritance of X and Y-



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chromosomes in humans. 4.3.6

State that some genes are present on the X chromosome and absent from the shorter Y chromosome in humans.

4.3.7

Define sex linkage.

4.3.8

Describe the inheritance of colour blindness and haemophilia as examples of sex linkage.

4.3.9

State that a human female can be homozygous or heterozygous with respect to sex-linked genes.

4.3.10

Explain that female carriers are heterozygous for X-linked recessive alleles.

4.3.11

Predict the genotypic and phenotypic ratios of offspring of monohybrid crosses involving any of the above patterns of inheritance.

4.3.12

Deduce the genotypes and phenotypes of individuals in pedigree charts.

Assessment statement


4.4

Genetic engineering and biotechnology

4.4.1

Outline the use of polymerase chain reaction (PCR) to copy and amplify minute quantities of DNA.

4.4.2

State that, in gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size.

4.4.3

State that gel electrophoresis of DNA is used in DNA profiling.

4.4.4

Describe the application of DNA profiling to determine paternity and also in forensic investigations.

4.4.5

Analyse DNA profiles to draw conclusions about paternity or forensic investigations.

4.4.6

Outline three outcomes of the sequencing of the complete human genome.

4.4.7

State that, when genes are transferred between species, the amino acid sequence of polypeptides translated from them is unchanged because the genetic code is universal.

4.4.8

Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell), restriction enzymes (endonucleases) and DNA ligase.


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4.4.9

State two examples of the current uses of genetically modified crops or animals.

4.4.10

Discuss the potential benefits and possible harmful effects of one example of genetic modification.

4.4.11

Define clone.

4.4.12

Outline a technique for cloning using differentiated animal cells.

4.4.13

Discuss the ethical issues of therapeutic cloning in humans.

Topic 5: Ecology and evolution (16 hours) Assessment statement


5.1

Communities and ecosystems

5.1.1

Define species, habitat, population, community, ecosystem and ecology.

5.1.2

Distinguish between autotroph and heterotroph.

5.1.3

Distinguish between consumers, detritivores and saprotrophs.

5.1.4

Describe what is meant by a food chain, giving three examples, each with at least three linkages (four organisms).

5.1.5

Describe what is meant by a food web.

5.1.6

Define trophic level.

5.1.7

Deduce the trophic level of organisms in a food chain and a food web.

5.1.8

Construct a food web containing up to 10 organisms, using appropriate information.

5.1.9

State that light is the initial energy source for almost all communities.

5.1.10

Explain the energy flow in a food chain.

5.1.11

State that energy transformations are never 100% efficient.

5.1.12

Explain reasons for the shape of pyramids of energy.

5.1.13

Explain that energy enters and leaves ecosystems, but nutrients must be recycled.


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5.1.14

State that saprotrophic bacteria and fungi (decomposers) recycle nutrients. Assessment statement

5.2

The greenhouse effect

5.2.1

Draw and label a diagram of the carbon cycle to show the processes involved.

5.2.2

Analyse the changes in concentration of atmospheric carbon dioxide using historical records.

5.2.3

Explain the relationship between rises in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect.

5.2.4

Outline the precautionary principle.

5.2.5

Evaluate the precautionary principle as a justification for strong action in response to the threats posed by the enhanced greenhouse effect.

5.2.6

Outline the consequences of a global temperature rise on arctic ecosystems. Assessment statement

5.3

Populations

5.3.1

Outline how population size is affected by natality, immigration, mortality and emigration.

5.3.2

Draw and label a graph showing a sigmoid (S-shaped) population growth curve.

5.3.3

Explain the reasons for the exponential growth phase, the plateau phase and the transitional phase between these two phases.

5.3.4

List three factors that set limits to population increase. Assessment statement

5.4

Evolution



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5.4.1

Define evolution.

5.4.2

Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures.

5.4.3

State that populations tend to produce more offspring than the environment can support.

5.4.4

Explain that the consequence of the potential overproduction of offspring is a struggle for survival.

5.4.5

State that the members of a species show variation.

5.4.6

Explain how sexual reproduction promotes variation in a species.

5.4.7

Explain how natural selection leads to evolution.

5.4.8

Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria. Assessment statement


5.5

Classification

5.5.1

Outline the binomial system of nomenclature.

5.5.2

List seven levels in the hierarchy of taxa—kingdom, phylum, class, order, family, genus and species— using an example from two different kingdoms for each level.

5.5.3

Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.

5.5.4

Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.

5.5.5

Apply and design a key for a group of up to eight organisms.


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Topic 6: Human health and physiology (20 hours) Assessment statement 6.1

Digestion

6.1.1

Explain why digestion of large food molecules is essential.

6.1.2

Explain the need for enzymes in digestion.

6.1.3

State the source, substrate, products and optimum pH conditions for one amylase, one protease and one lipase.

6.1.4

Draw and label a diagram of the digestive system.

6.1.5

Outline the function of the stomach, small intestine and large intestine.

6.1.6

Distinguish between absorption and assimilation.

6.1.7

Explain how the structure of the villus is related to its role in absorption and transport of the products of digestion. Assessment statement

6.2

The transport system

6.2.1

Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart.

6.2.2

State that the coronary arteries supply heart muscle with oxygen and nutrients.

6.2.3

Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves.

6.2.4

Outline the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline).

6.2.5

Explain the relationship between the structure and function of arteries, capillaries and veins.



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6.2.6

State that blood is composed of plasma, erythrocytes, leucocytes (phagocytes and lymphocytes) and platelets.

6.2.7

State that the following are transported by the blood: nutrients, oxygen, carbon dioxide, hormones, antibodies, urea and heat. Assessment statement

6.3

Defence against infectious disease

6.3.1

Define pathogen.

6.3.2

Explain why antibiotics are effective against bacteria but not against viruses.

6.3.3

Outline the role of skin and mucous membranes in defence against pathogens.

6.3.4

Outline how phagocytic leucocytes ingest pathogens in the blood and in body tissues.

6.3.5

Distinguish between antigens and antibodies.

6.3.6

Explain antibody production.

6.3.7

Outline the effects of HIV on the immune system.

6.3.8

Discuss the cause, transmission and social implications of AIDS. Assessment statement

6.4

Gas exchange

6.4.1

Distinguish between ventilation, gas exchange and cell respiration.

6.4.2

Explain the need for a ventilation system.

6.4.3

Describe the features of alveoli that adapt them to gas exchange.

6.4.4

Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli.

6.4.5

Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by



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the internal and external intercostal muscles, the diaphragm and abdominal muscles. Assessment statement


6.5

Nerves, hormones and homeostasis

6.5.1

State that the nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses.

6.5.2

Draw and label a diagram of the structure of a motor neuron.

6.5.3

State that nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons.

6.5.4

Define resting potential and action potential (depolarization and repolarization).

6.5.5

Explain how a nerve impulse passes along a non-myelinated neuron.

6.5.6

Explain the principles of synaptic transmission.

6.5.7

State that the endocrine system consists of glands that release hormones that are transported in the blood.

6.5.8

State that homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature and water balance.

6.5.9

Explain that homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms.

6.5.10

Explain the control of body temperature, including the transfer of heat in blood, and the roles of the hypothalamus, sweat glands, skin arterioles and shivering.

6.5.11

Explain the control of blood glucose concentration, including the roles of glucagon, insulin and α and β cells in the pancreatic islets.

6.5.12

Distinguish between type I and type II diabetes.


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Reproduction

6.6.1

Draw and label diagrams of the adult male and female reproductive systems.

6.6.2

Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormone), LH (luteinising hormone), oestrogen and progesterone.

6.6.3

Annotate a graph showing hormone levels in the menstrual cycle, illustrating the relationship between changes in hormone levels and ovulation, menstruation and thickening of the endometrium.

6.6.4

List three roles of testosterone in males.

6.6.5

Outline the process of in vitro fertilization (IVF).

6.6.6

Discuss the ethical issues associated with IVF.


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AHL Students only Topic 7: Nucleic acids and proteins (11 hours) Assessment statement 7.1

DNA structure

7.1.1

Describe the structure of DNA, including the antiparallel strands, 3’–5’ linkages and hydrogen bonding between purines and pyrimidines.

7.1.2

Outline the structure of nucleosomes.

7.1.3

State that nucleosomes help to supercoil chromosomes and help to regulate transcription.

7.1.4

Distinguish between unique or single-copy genes and highly repetitive sequences in nuclear DNA.

7.1.5

State that eukaryotic genes can contain exons and introns.




Done in class

7.2

DNA replication

7.2.1

State that DNA replication occurs in a 5’→3’ direction.

7.2.2

Explain the process of DNA replication in prokaryotes, including the role of enzymes (helicase, DNA polymerase, RNA primase and DNA ligase), Okazaki fragments and deoxynucleoside triphosphates.

7.2.3

State that DNA replication is initiated at many points in eukaryotic chromosomes. Assessment statement

7.3

Transcription

7.3.1

State that transcription is carried out in a 5’→3’ direction.

7.3.2

Distinguish between the sense and antisense strands of DNA.

7.3.3

Explain the process of transcription in prokaryotes, including the role of the promoter region, RNA polymerase, nucleoside triphosphates and the terminator.

7.3.4

State that eukaryotic RNA needs the removal of introns to form mature mRNA.

Revised at home

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Comment [MS1]: Check with the syllabus



7.4

Translation

7.4.1

Explain that each tRNA molecule is recognized by a tRNA-activating enzyme that binds a specific amino acid to the tRNA, using ATP for energy.

7.4.2

Outline the structure of ribosomes, including protein and RNA composition, large and small subunits, three tRNA binding sites and mRNA binding sites.

7.4.3

State that translation consists of initiation, elongation, translocation and termination.

7.4.4

State that translation occurs in a 5’→3’ direction.

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Comment [MS2]: check



7.4.5

Draw and label a diagram showing the structure of a peptide bond between two amino acids.

7.4.6

Explain the process of translation, including ribosomes, polysomes, start codons and stop codons.

7.4.7

State that free ribosomes synthesize proteins for use primarily within the cell, and that bound ribosomes synthesize proteins primarily for secretion or for lysosomes. Assessment statement

7.5

Proteins

7.5.1

Explain the four levels of protein structure, indicating the significance of each level.

7.5.2

Outline the difference between fibrous and globular proteins, with reference to two examples of each protein type.

7.5.3

Explain the significance of polar and non-polar amino acids.

7.5.4

State four functions of proteins, giving a named example of each. Assessment statement

7.6

Enzymes

7.6.1

State that metabolic pathways consist of chains and cycles of enzyme-catalysed reactions.

7.6.2

Describe the induced-fit model.

7.6.3

Explain that enzymes lower the activation energy of the chemical reactions that they catalyse.

7.6.4

Explain the difference between competitive and non-competitive inhibition, with reference to one example of each.

7.6.5

Explain the control of metabolic pathways by end-product inhibition, including the role of allosteric sites.



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Topic 8: Cell respiration and photosynthesis (10 hours) Assessment statement 8.1

Cell respiration

8.1.1

State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.

8.1.2

Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.

8.1.3

Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.

8.1.4

Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

8.1.5

Explain oxidative phosphorylation in terms of chemiosmosis.

8.1.6

Explain the relationship between the structure of the mitochondrion and its function. Assessment statement

8.2

Photosynthesis

8.2.1

Draw and label a diagram showing the structure of a chloroplast as seen in electron micrographs.

8.2.2

State that photosynthesis consists of light-dependent and light-independent reactions.

8.2.3

Explain the light-dependent reactions.

8.2.4

Explain photophosphorylation in terms of chemiosmosis.

8.2.5

Explain the light-independent reactions.

8.2.6

Explain the relationship between the structure of the chloroplast and its function.

8.2.7

Explain the relationship between the action spectrum and the absorption spectrum of photosynthetic pigments in green plants.



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8.2.8

Explain the concept of limiting factors in photosynthesis, with reference to light intensity, temperature and concentration of carbon dioxide.

Topic 9: Plant science (11 hours) Assessment statement 9.1

Plant structure and growth

9.1.1

Draw and label plan diagrams to show the distribution of tissues in the stem and leaf of a dicotyledonous plant.

9.1.2

Outline three differences between the structures of dicotyledonous and monocotyledonous plants.

9.1.3

Explain the relationship between the distribution of tissues in the leaf and the functions of these tissues.

9.1.4

Identify modifications of roots, stems and leaves for different functions: bulbs, stem tubers, storage roots and tendrils.

9.1.5

State that dicotyledonous plants have apical and lateral meristems.

9.1.6

Compare growth due to apical and lateral meristems in dicotyledonous plants.

9.1.7

Explain the role of auxin in phototropism as an example of the control of plant growth. Assessment statement

9.2

Transport in angiospermophytes

9.2.1

Outline how the root system provides a large surface area for mineral ion and water uptake by means of branching and root hairs.

9.2.2

List ways in which mineral ions in the soil move to the root.

9.2.3

Explain the process of mineral ion absorption from the soil into roots by active transport.

9.2.4

State that terrestrial plants support themselves by means of thickened cellulose, cell turgor and lignified xylem.



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9.2.5

Define transpiration.

9.2.6

Explain how water is carried by the transpiration stream, including the structure of xylem vessels, transpiration pull, cohesion, adhesion and evaporation.

9.2.7

State that guard cells can regulate transpiration by opening and closing stomata.

9.2.8

State that the plant hormone abscisic acid causes the closing of stomata.

9.2.9

Explain how the abiotic factors light, temperature, wind and humidity, affect the rate of transpiration in a typical terrestrial plant.

9.2.10

Outline four adaptations of xerophytes that help to reduce transpiration.

9.2.11

Outline the role of phloem in active translocation of sugars (sucrose) and amino acids from source (photosynthetic tissue and storage organs) to sink (fruits, seeds, roots). Assessment statement

9.3

Reproduction in angiospermophytes

9.3.1

Draw and label a diagram showing the structure of a dicotyledonous animal-pollinated flower.

9.3.2

Distinguish between pollination, fertilization and seed dispersal.

9.3.3

Draw and label a diagram showing the external and internal structure of a named dicotyledonous seed.

9.3.4

Explain the conditions needed for the germination of a typical seed.

9.3.5

Outline the metabolic processes during germination of a starchy seed.

9.3.6

Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome.


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Topic 10: Genetics (6 hours) Assessment statement 10.1

Meiosis

10.1.1

Describe the behaviour of the chromosomes in the phases of meiosis.



10.1.2

Outline the formation of chiasmata in the process of crossing over.

10.1.3

Explain how meiosis results in an effectively infinite genetic variety in gametes through crossing over in prophase I and random orientation in metaphase I.

10.1.4

State Mendel’s law of independent assortment.

10.1.5

Explain the relationship between Mendel’s law of independent assortment and meiosis. Assessment statement

10.2

Dihybrid crosses and gene linkage

10.2.1

Calculate and predict the genotypic and phenotypic ratio of offspring of dihybrid crosses involving unlinked autosomal genes.

10.2.2

Distinguish between autosomes and sex chromosomes.

10.2.3

Explain how crossing over between non-sister chromatids of a homologous pair in prophase I can result in an exchange of alleles.

10.2.4

Define linkage group.

10.2.5

Explain an example of a cross between two linked genes.

10.2.6

Identify which of the offspring are recombinants in a dihybrid cross involving linked genes. Assessment statement

10.3

Polygenic inheritance

10.3.1

Define polygenic inheritance.

10.3.2

Explain that polygenic inheritance can contribute to continuous variation using two examples, one of which must be human skin colour.



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Topic 11: Human health and physiology (17 hours) Assessment statement 11.1

Defence against infectious disease

11.1.1

Describe the process of blood clotting.

11.1.2

Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity.

11.1.3

Define active and passive immunity.

11.1.4

Explain antibody production.

11.1.5

Describe the production of monoclonal antibodies and their use in diagnosis and in treatment.

11.1.6

Explain the principle of vaccination.

11.1.7

Discuss the benefits and dangers of vaccination. Assessment statement

11.2

Muscles and movement

11.2.1

State the roles of bones, ligaments, muscles, tendons and nerves in human movement.

11.2.2

Label a diagram of the human elbow joint, including cartilage, synovial fluid, joint capsule, named bones and antagonistic muscles (biceps and triceps).

11.2.3

Outline the functions of the structures in the human elbow joint named in 11.2.2.

11.2.4

Compare the movements of the hip joint and the knee joint.

11.2.5

Describe the structure of striated muscle fibres, including the myofibrils with light and dark bands, mitochondria, the sarcoplasmic reticulum, nuclei and the sarcolemma.

11.2.6

Draw and label a diagram to show the structure of a sarcomere, including Z lines, actin filaments, myosin filaments with heads, and the resultant light and dark bands.

11.2.7

Explain how skeletal muscle contracts, including the release of calcium ions from the sarcoplasmic



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reticulum, the formation of cross-bridges, the sliding of actin and myosin filaments, and the use of ATP to break cross-bridges and re-set myosin heads. 11.2.8

Analyse electron micrographs to find the state of contraction of muscle fibres. Assessment statement

11.3

The kidney

11.3.1

Define excretion.

11.3.2

Draw and label a diagram of the kidney.

11.3.3

Annotate a diagram of a glomerulus and associated nephron to show the function of each part.

11.3.4

Explain the process of ultrafiltration, including blood pressure, fenestrated blood capillaries and basement membrane.

11.3.5

Define osmoregulation.

11.3.6

Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule, including the roles of microvilli, osmosis and active transport.

11.3.7

Explain the roles of the loop of Henle, medulla, collecting duct and ADH (vasopressin) in maintaining the water balance of the blood.

11.3.8

Explain the differences in the concentration of proteins, glucose and urea between blood plasma, glomerular filtrate and urine.

11.3.9

Explain the presence of glucose in the urine of untreated diabetic patients. Assessment statement

11.4

Reproduction

11.4.1

Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (Leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells.

11.4.2

Outline the processes involved in spermatogenesis within the testis, including mitosis, cell growth, the



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two divisions of meiosis and cell differentiation. 11.4.3

State the role of LH, testosterone and FSH in spermatogenesis.

11.4.4

Annotate a diagram of the ovary to show the location and function of germinal epithelium, primary follicles, mature follicle and secondary oocyte.

11.4.5

Outline the processes involved in oogenesis within the ovary, including mitosis, cell growth, the two divisions of meiosis, the unequal division of cytoplasm and the degeneration of polar body.

11.4.6

Draw and label a diagram of a mature sperm and egg.

11.4.7

Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen.

11.4.8

Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes.

11.4.9

Describe the process of fertilization, including the acrosome reaction, penetration of the egg membrane by a sperm and the cortical reaction.

11.4.10 Outline the role of HCG in early pregnancy. 11.4.11 Outline early embryo development up to the implantation of the blastocyst. 11.4.12 Explain how the structure and functions of the placenta, including its hormonal role in secretion of estrogen and progesterone, maintain pregnancy. 11.4.13 State that the foetus is supported and protected by the amniotic sac and amniotic fluid. 11.4.14 State that materials are exchanged between the maternal and foetal blood in the placenta. 11.4.15 Outline the process of birth and its hormonal control, including the changes in progesterone and oxytocin levels and positive feedback.



Option for SL only Option A: Human nutrition and health (15 hours) Assessment statement


A.1

Components of the Human Diet

A.1.1

Define nutrient.

A.1.2

List the type of nutrients that are essential in the human diet, including amino acids, fatty acids, minerals, vitamins and water.

A.1.3

State that non-essential amino acids can be synthesized in the body from other nutrients.

A.1.4

Outline the consequences of protein deficiency malnutrition.

A.1.5

Explain the causes and consequences of phenylketonuria (PKU) and how early diagnosis and a special diet can reduce the consequences.

A.1.6

Outline the variation in the molecular structure of fatty acids, including saturated fatty acids, cis and trans unsaturated fatty acids, monounsaturated and polyunsaturated fatty acids.

A.1.7

Evaluate the health consequences of diets rich in the different types of fatty acid.

A.1.8

Distinguish between minerals and vitamins in terms of their chemical nature.

A.1.9

Outline two of the methods that have been used to determine the recommended daily intake of vitamin C.

A.1.10

Discuss the amount of vitamin C that an adult should consume per day, including the level needed to prevent scurvy, claims that higher intakes give protection against upper respiratory tract infections, and the danger of rebound malnutrition.

A.1.11

List the sources of vitamin D in human diets.

A.1.12

Discuss how the risk of vitamin D deficiency from insufficient exposure to sunlight can be balanced against the risk of contracting malignant melanoma.

A.1.13

Explain the benefits of artificial dietary supplementation as a means of preventing malnutrition, using iodine as an example.

A.1.14

Outline the importance of fibre as a component of a balanced diet.


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Assessment statement A2

Energy in Human Diets

A.2.1

Compare the energy content per 100 g of carbohydrate, fat and protein.

A.2.2

Compare the main dietary sources of energy in different ethnic groups.

A.2.3

Explain the possible health consequences of diets rich in carbohydrates, fats and proteins.

A.2.4

Outline the function of the appetite control centre in the brain.

A.2.5

Calculate body mass index (BMI) from the body mass and height of a person.

A.2.6

Distinguish, using the body mass index, between being underweight, normal weight, overweight and obese.

A.2.7

Outline the reasons for increasing rates of clinical obesity in some countries, including availability of cheap high-energy foods, large portion sizes, increasing use of vehicles for transport, and a change from active to sedentary occupations.

A.2.8

Outline the consequences of anorexia nervosa. Assessment statement

A3

Special issues in human nutrition

A.3.1

Distinguish between the composition of human milk and artificial milk used for bottle-feeding babies.

A.3.2

Discuss the benefits of breastfeeding.

A.3.3

Outline the causes and symptoms of type II diabetes.

A.3.4

Explain the dietary advice that should be given to a patient who has developed type II diabetes.

A.3.5

Discuss the ethical issues concerning the eating of animal products, including honey, eggs, milk and meat.

A.3.6

Evaluate the benefits of reducing dietary cholesterol in lowering the risk of coronary heart disease.



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A.3.7

Discuss the concept of food miles and the reasons for consumers choosing foods to minimize food miles.

Options for SL and HL Option F: Microbes and biotechnology (15/22 hours) Assessment statement F1

Diversity of microbes

F.1.1

Outline the classification of living organisms into three domains.

F.1.2

Explain the reasons for the reclassification of living organisms into three domains.

F.1.3

Distinguish between the characteristics of the three domains.

F.1.4

Outline the wide diversity of habitat in the Archae, as exemplified by methanogens, thermophiles and halophiles.

F.1.5

Outline the diversity of Eubacteria, including shape and cell wall structure.

F.1.6

State, with one example, that some bacteria form aggregates that show characteristics not seen in individual bacteria.

F.1.7

Compare the structure of the cell walls of Gram-positive and Gram-negative Eubacteria.

F.1.8

Outline the diversity of structure in viruses including: naked capsid versus enveloped capsid; DNA versus RNA; and single stranded versus double stranded DNA or RNA.

F.1.9

Outline the diversity of microscopic eukaryotes, as illustrated by Saccharomyces, Amoeba, Plasmodium, Paramecium, Euglena and Chlorella. Assessment statement

F2

Microbes and the environment

F.2.1

List the roles of microbes in ecosystems, including producers, nitrogen fixers and decomposers.



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F.2.2

Draw and label a diagram of the nitrogen cycle.

F.2.3

State the roles of Rhizobium, Azotobacter, Nitrosomonas, Nitrobacter and Pseudomonas denitrificans in the nitrogen cycle.

F.2.4

Outline the conditions that favour denitrification and nitrification.

F.2.5

Explain the consequences of releasing raw sewage and nitrate fertilizer into rivers.

F.2.6

Outline the role of saprotrophic bacteria in the treatment of sewage using trickling filter beds and reed bed systems.

F.2.7

State that biomass can be used as raw material for the production of fuels such as methane and ethanol.

F.2.8

Explain the principles involved in the generation of methane from biomass, including the conditions needed, organisms involved and the basic chemical reactions that occur. Assessment statement

F3

Microbes and biotechnology

F.3.1

State that reverse transcriptase catalyses the production of DNA from RNA.

F.3.2

Explain how reverse transcriptase is used in molecular biology.

F.3.3

Distinguish between somatic and germ line therapy.

F.3.4

Outline the use of viral vectors in gene therapy.

F.3.5

Discuss the risks of gene therapy.

Assessment statement F4

Microbes and food production

F.4.1

Explain the use of Saccharomyces in the production of beer, wine and bread.

F.4.2

Outline the production of soy sauce using Aspergillus oryzae.



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F.4.3

Explain the use of acids and high salt or sugar concentrations in food preservation.

F.4.4

Outline the symptoms, method of transmission and treatment of one named example of food poisoning. Assessment statement

F5

Metabolism of microbes

F.5.1

Define the terms photoautotroph, photoheterotroph, chemoautotroph and chemoheterotroph.

F.5.2

State one example of a photoautotroph, photoheterotroph, chemoautotroph and chemoheterotroph.

F.5.3

Compare photoautotrophs with photoheterotrophs in terms of energy sources and carbon sources.

F.5.4

Compare chemoautotrophs with chemoheterotrophs in terms of energy sources and carbon sources.

F.5.5

Draw and label a diagram of a filamentous cyanobacterium.

F.5.6

Explain the use of bacteria in the bioremediation of soil and water. Assessment statement

F6

Microbes and disease

F.6.1

List six methods by which pathogens are transmitted and gain entry to the body.

F.6.2

Distinguish between intracellular and extracellular bacterial infection using Chlamydia and Streptococcus as examples.

F.6.3

Distinguish between endotoxins and exotoxins.

F.6.4

Evaluate methods of controlling microbial growth by irradiation, pasteurization, antiseptics and disinfectants.

F.6.5

Outline the mechanism of the action of antibiotics, including inhibition of synthesis of cell walls, proteins and nucleic acids.

F.6.6

Outline the lytic life cycle of the influenza virus.

F.6.7

Define epidemiology.



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F.6.8

Discuss the origin and epidemiology of one example of a pandemic.

F.6.9

Describe the cause, transmission and effects of malaria, as an example of disease caused by a protozoan.

F.6.10

Discuss the prion hypothesis for the cause of spongiform encephalopathies.

Option G: Ecology and conservation (15/22 hours) Assessment statement


G1

Community ecology

G.1.1

Outline the factors that affect the distribution of plant species, including temperature, water, light, soil pH, salinity and mineral nutrients.

G.1.2

Explain the factors that affect the distribution of animal species, including temperature, water, breeding sites, food supply and territory.

G.1.3

Describe one method of random sampling, based on quadrat methods, that is used to compare the population size of two plant or two animal species.

G.1.4

Outline the use of a transect to correlate the distribution of plant or animal species with an abiotic variable.

G.1.5

Explain what is meant by the niche concept, including an organism’s spatial habitat, its feeding activities and its interactions with other species.

G.1.6

Outline the following interactions between species, giving two examples of each: competition, herbivory, predation, parasitism and mutualism.

G.1.7

Explain the principle of competitive exclusion.

G.1.8

Distinguish between fundamental and realized niches.

G.1.9

Define biomass.

G.1.10

Describe one method for the measurement of biomass of different trophic levels in an ecosystem.


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Assessment statement G2

Ecosystems and biomes

G.2.1

Define gross production, net production and biomass.

G.2.2

Calculate values for gross production and net production using the equation: gross production – respiration = net production.

G.2.3

Discuss the difficulties of classifying organisms into trophic levels.

G.2.4

Explain the small biomass and low numbers of organisms in higher trophic levels.

G.2.5

Construct a pyramid of energy, given appropriate information.

G.2.6

Distinguish between primary and secondary succession, using an example of each.

G.2.7

Outline the changes in species diversity and production during primary succession.

G.2.8

Explain the effects of living organisms on the abiotic environment, with reference to the changes occurring during primary succession.

G.2.9

Distinguish between biome and biosphere.

G.2.10

Explain how rainfall and temperature affect the distribution of biomes.

G.2.11

Outline the characteristics of six major biomes. Assessment statement

G3

Impacts of humans on ecosystems

G.3.1

Calculate the Simpson diversity index for two local communities.

G.3.2

Analyse the biodiversity of the two local communities using the Simpson index.

G.3.3

Discuss reasons for the conservation of biodiversity using rainforests as an example.

G.3.4

List three examples of the introduction of alien species that have had significant impacts on ecosystems.



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G.3.5

Discuss the impacts of alien species on ecosystems.

G.3.6

Outline one example of biological control of invasive species.

G.3.7

Define biomagnification.

G.3.8

Explain the cause and consequences of biomagnification, using a named example.

G.3.9

Outline the effects of ultraviolet (UV) radiation on living tissues and biological productivity.

G.3.10

Outline the effect of chlorofluorocarbons (CFCs) on the ozone layer.

G.3.11

State that ozone in the stratosphere absorbs UV radiation. Assessment statement

G4

Conservation of biodiversity

G.4.1

Explain the use of biotic indices and indicator species in monitoring environmental change.

G.4.2

Outline the factors that contributed to the extinction of one named animal species.

G.4.3

Outline the biogeographical features of nature reserves that promote the conservation of diversity.

G.4.4

Discuss the role of active management techniques in conservation.

G.4.5

Discuss the advantages of in situ conservation of endangered species (terrestrial and aquatic nature reserves).

G.4.6

Outline the use of ex situ conservation measures, including captive breeding of animals, botanic gardens and seed banks. Assessment statement

G5

Population ecology

G.5.1

Distinguish between r-strategies and K-strategies.

G.5.2

Discuss the environmental conditions that favour either r-strategies or K-strategies.



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G.5.3

Describe one technique used to estimate the population size of an animal species based on a capture– mark–release–recapture method.

G.5.4

Describe the methods used to estimate the size of commercial fish stocks.

G.5.5

Outline the concept of maximum sustainable yield in the conservation of fish stocks.

G.5.6

Discuss international measures that would promote the conservation of fish.


Appendix II – Summary of the assessment specifications Standard Level

Component Paper 1 Paper 2

Paper 3

Overall Weighting (%) 20 32

24

Duration (hours) ¾ 1¼

1

Format and Syllabus Coverage 30 multiple-choice questions on the core Section A: one data-based question and several short-answer questions on the core (all compulsory) Section B: one extended response question on the core (from a choice of three) Several short-answer questions in each of the two options studied (all compulsory)

Higher Level

Paper 1

Overall Weighting (%) 20

Paper 2

36

2¼

Paper 3

20

1¼

Component

Duration (hours) 1

Format and Syllabus Coverage 40 multiple-choice questions (± 15 common to SL plus about five more on the core and about 20 more on the AHL) Section A: one data-based question and several short-answer questions on the core and the AHL (all compulsory) Section B: two extended response questions on the core and AHL (from a choice of four) Several short-answer questions and one extended response question in each of the two options studied (all compulsory)

For both SL and HL, calculators are not permitted in paper 1 but are required in papers 2 and 3, where programmable graphic display calculators are allowed.

Appendix III: IB Internal Assessment Criteria There are five assessment criteria that are used to assess the work of both SL and HL students. • Design—D • Data collection and processing—DCP • Conclusion and evaluation—CE • Manipulative skills—MS • Personal skills—PS The first three criteria—design (D), data collection and processing (DCP) and conclusion and evaluation (CE)—are each assessed twice. Manipulative skills (MS) is assessed summatively over the whole course and the assessment should be based on a wide range of manipulative skills. Personal skills (PS) is assessed once only and this will be during the group 4 project. Each of the assessment criteria can be separated into three aspects as shown in the following sections. Descriptions are provided to indicate what is expected in order to meet the requirements of a given aspect completely (c) and partially (p). A description is also given for circumstances in which the requirements are not satisfied, not at all (n). A “complete” is awarded 2 marks, a “partial” 1 mark and a “not at all” 0 marks. The maximum mark for each criterion is 6 (representing three “completes”). D x 2 = 12 DCP x2 = 12 CE x2 = 12 MS x1 = 6 PS x1 = 6 This makes a total mark out of 48. The marks for each of the criteria are added together to determine the final mark out of 48 for the IA component. This is then scaled at IBCA to give a total out of 24%.


Design

Levels/marks

Complete/2

Partial/1

Not at all/0

Aspect 1 Defining the problem and selecting variables Formulates a focused problem/research question and identifies the relevant variables. Formulates a problem/ research question that is incomplete or identifies only some relevant variables. Does not identify a problem/research question and does not identify any relevant variables.

Aspect 2 Controlling variables

Aspect 3 Developing a method for collection of data

Designs a method for the effective control of the variables.

Develops a method that allows for the collection of sufficient relevant data. Develops a method that allows for the collection of insufficient relevant data.

Designs a method that makes some attempt to control the variables. Designs a method that does not control the variables.

Develops a method that does not allow for any relevant data to be collected.

Aspect 3 Presenting processed data Presents processed data appropriately and, where relevant, includes errors and uncertainties.

Data collection and processing

Levels/marks

Aspect 1 Recording raw data

Aspect 2 Processing raw data

Complete/2

Records appropriate quantitative and associated qualitative raw data, including units and uncertainties where relevant. Records appropriate quantitative and associated qualitative raw data, but with some mistakes or omissions. Does not record any appropriate quantitative raw data or raw data is incomprehensible.

Processes the quantitative raw data correctly.

Partial/1

Not at all/0

Processes quantitative raw data, but with some mistakes and/or omissions. No processing of quantitative raw data is carried out or major mistakes are made in processing.

Presents processed data appropriately, but with some mistakes and/or omissions. Presents processed data inappropriately or incomprehensibly



Conclusion and evaluation

Levels/marks

Aspect 1 Concluding

Complete/2

States a conclusion, with justification, based on a reasonable interpretation of the data. States a conclusion based on a reasonable interpretation of the data.

Partial/1

Not at all/0

States no conclusion or the conclusion is based on an unreasonable interpretation of the data.

Aspect 2 Evaluating procedures Evaluates weaknesses and limitations.

Identifies some weaknesses and limitations, but the evaluation is weak or missing. Identifies irrelevant weaknesses and limitations.

Aspect 3 Improving the investigation Suggests realistic improvements in respect of identified weaknesses and limitations. Suggests only superficial improvements. Suggests unrealistic improvements.

Manipulative skills (assessed summatively)

Levels/marks

Complete/2

Partial/1

Not at all/0

Aspect 1 Following instructions* Follows instructions accurately, adapting to new circumstances (seeking assistance when required). Follows instructions but requires assistance. Rarely follows instructions or requires constant supervision.

Aspect 2 Carrying out techniques Competent and methodical in the use of a range of techniques and equipment.

Aspect 3 Working safely

Usually competent and methodical in the use of a range of techniques and equipment. Rarely competent and methodical in the use of a range of techniques and equipment.

Usually pays attention to safety issues.

Pays attention to safety issues.

Rarely pays attention to safety issues.

*Instructions may be in a variety of forms: oral, written worksheets, diagrams, photographs, videos, flow charts, audio tapes, models, computer programs, and so on, and need not originate from the teacher.



Personal skills (for Group 4 project assessment only)

Levels/marks

Aspect 1 Self-motivation and perseverance Approaches the project with self-motivation and follows it through to completion.

Aspect 2 Working within a team

Aspect 3 Self-reflection

Collaborates and communicates in a group situation and integrates the views of others.

Partial/1

Completes the project but sometimes lacks self-motivation.

Exchanges some views but requires guidance to collaborate with others.

Not at all/0

Lacks perseverance and motivation.

Makes little or no attempt to collaborate in a group situation.

Shows a thorough awareness of their own strengths and weaknesses and gives thoughtful consideration to their learning experience. Shows limited awareness of their own strengths and weaknesses and gives some consideration to their learning experience. Shows no awareness of their own strengths and weaknesses and gives no consideration to their learning experience.

Complete/2



Appendix IV – Internal Assessment Checklist

Design criteria Is the research question carefully worded? Does the research question include the dependent and independent variable? Is the independent variable clearly stated? Does the dependent variable directly stem from the independent variable? Are all controlled variables clearly stated and explained as to how they remain constant? Are the experimental groups and control groups evident? Does the control group differ from the experimental group(s) only by the independent variable? Are the independent and the dependent variables quantitative? Is the independent variable set up so there are 5 intervals? Are there at least 5 trials at each interval of the independent variable? Are regular measurements of controlled variables included? Is there a clear picture or diagram of the experimental apparatus? Are all materials used clearly and precisely listed? (exact sizes of containers and concentrations of solutions must be stated) Data collection and processing criteria Is the raw data presented in a table with an appropriate title and in the proper format? Are all parts of tables presented clearly labelled? Is the precision of the measuring device(s) used included with each table? (This includes + the smallest division of the device.) Are all uncertainties presented? Is the raw data properly processed? (This may include statistical tests, percent change, or simple means.) Is the processed data presented properly in a table or in a graphical representation? Is the use of decimals consistent? Do the decimals not exceed the capability of the measuring devices? Are uncertainties included with tables or graphs showing processed data? For statistical tests, is a clear explanation of the test given with at least one clear example of the test being applied to the raw data? Conclusion and evaluation Is there a clear pattern shown by your processed data? Is a clear conclusion, using the processed data, presented? Is the actual processed data used in the conclusion? Is there a correlation between your work and literature values? (if applicable) Are weaknesses of experimental design stated? Is the quality of the data discussed? Are there references to equipment or processes in the discussion of the design weaknesses? Are suggested modifications to the design presented based on the weaknesses presented? Are the suggested modifications specific and significant? Laboratory skills (assessed summatively) Do you follow directions? Do you seek assistance when appropriate? (Independence is encouraged.) Are you carrying out proper safety measures consistently? Can you effectively use a variety of biological techniques? Are you able to properly use common experimental equipment in carrying out biological procedures? Are you consistently working in the lab in a way that does not put yourself or others in harm’s way?


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