Gareth Williams Keith h John Johnso son, n, Lawr Lawrie ie Ryan Ryan,, Bob Bob Wake Wakefi fiel eld, d, Ph Phil il Buny Bunyan an,, With With the the supp suppor ortt of : Keit Keit Keith h Hirs Hirst, t, Eric Erica a Clar Clark, k, Roge Rogerr Fros Frost, t, Nick Nick Paul Paul,, Paul Paul Conn Connel ell, l, Byro Byron n Daws Dawson on,, Niva Niva Mile Miles, s, Davi David d Barr Barret ett, t, Jane Janett Hawk Hawkin ins, s, John John Baile Bailey, y, Rosie Rosie Daviso Davison, n, Tom Spice Spicer, r, Adrian Adrian Wheato Wheaton, n, Diana Diana Willia Williams. ms.
© Gareth Gareth Williams Williams,, 2011
Students’ Checklists Stud Studen ents ts lear learn n best best when when th they ey are are clea clearr abou aboutt what what they they sh shoul ould d know know and unders understan tand. d. To help help your your st stud uden ents ts,, we prov provid ide e a ph phot otoc ocop opia iabl ble e Check Checklis listt for each each top topic. ic. Each Each Chec Checkl klis istt has has sect sectio ions ns on ‘Wha ‘Whatt I shou should ld know know’’ and ‘Wh ‘What I should ould be able to do’. do’. On the the CD High Highe er H . Tier concepts are marked J A Chec Checkl klis istt has has 3 poss possib ible le uses uses:: ive to your your stud tudents nts at the the star tart of the the top topic, ic, • To give so they can use it for self-assessment and ti tick ck off off each each it item em as they they unde unders rsta tand nd it it.. Stud Studen ents ts will will be able able to ti tick ck off off it item emss for for each each less lesson on.. This This can can be very very moti motiva vatin ting g and and enco encour urag agin ing. g. used by the the stud tudents nts as a summary , to help • To be use th thei eirr revi revisi sion on for for th the e inte intern rnal al and and GCSE GCSE exam examin inat atio ions ns.. Record of Achievement T o u s e a s p a r t o f a , whic wh ich h • also also inform informs s paren parents ts of their their child child’s ’s progre progress ss..
3 Enzymes
Name
Checklist Class
While studying this topic, tick off each item after you have covered it.
What I should know:
What I should be able to do:
J
Enzymes are biological catalysts that increase the rate of a reaction.
J
Draw diagrams to explain how the active site enables an enzyme to work.
J
Enzymes work on substances called substrates.
J
Carry out an experiment to show how catalase breaks down hydrogen peroxide.
J
Some enzymes can break down large molecules,others can build them up.
J
Carry out an experiment to see how quickly amylase can break down starch.
J
All enzymes are proteins.
J
J
Follow the course of an enzyme-controlled reaction as shown by a graph.
Each enzyme controls one particular reaction.
J
J
Plan an investigation into the effect of temperature on the action of an enzyme.
Enzymes can be used again and again.
J
J
Eachenzymehas an optimu optimum m temperature and is denatured by boiling.
Carry out an experiment to see the effect of pH on the action of a protease.
J
J
Most enzymes have an optimum pH and are affected by changes in acidic or alkaline conditions.
Interpret a graph showing the effect of pH on enzyme action.
J
J
Carbohydrases break down carbohydrates. Proteases break down proteins. Lipases Lipas es brea break k down fats.
Carry out an experiment to show how starch molecules can be built up from glucose molecules.
J
J
Use immobilised yeast enzyme to break down sucrose to simple sugars.
Immobilised enzymes are ‘fixed’ to small resin beads. They enable the enzyme to be used again and again.
J
Plan an investigation into the action of biological washing powders.
J
Use ectin ectinase ase enz
By collec collectin ting g the Check Checklis lists ts (and (and Revisi Revision on Quizz Quizzes) es) your your st stud uden ents ts can can build build up th thei eirr own own Revi Revisi sion on Book Book..
© Gareth Gareth Willia Williams, ms, 2011 2011
e to to extrac extractt juice juice from
Students’ Checklists Stud Studen ents ts lear learn n best best when when th they ey are are clea clearr abou aboutt what what they they sh shoul ould d know know and unders understan tand. d. To help help your your st stud uden ents ts,, we prov provid ide e a ph phot otoc ocop opia iabl ble e Check Checklis listt for each each top topic. ic. Each Each Chec Checkl klis istt has has sect sectio ions ns on ‘Wha ‘Whatt I shou should ld know know’’ and ‘Wh ‘What I should ould be able to do’. do’. On the the CD High Highe er H . Tier concepts are marked J A Chec Checkl klis istt has has 3 poss possib ible le uses uses:: ive to your your stud tudents nts at the the star tart of the the top topic, ic, • To give so they can use it for self-assessment and ti tick ck off off each each it item em as they they unde unders rsta tand nd it it.. Stud Studen ents ts will will be able able to ti tick ck off off it item emss for for each each less lesson on.. This This can can be very very moti motiva vatin ting g and and enco encour urag agin ing. g. used by the the stud tudents nts as a summary , to help • To be use th thei eirr revi revisi sion on for for th the e inte intern rnal al and and GCSE GCSE exam examin inat atio ions ns.. Record of Achievement T o u s e a s p a r t o f a , whic wh ich h • also also inform informs s paren parents ts of their their child child’s ’s progre progress ss..
3 Enzymes
Name
Checklist Class
While studying this topic, tick off each item after you have covered it.
What I should know:
What I should be able to do:
J
Enzymes are biological catalysts that increase the rate of a reaction.
J
Draw diagrams to explain how the active site enables an enzyme to work.
J
Enzymes work on substances called substrates.
J
Carry out an experiment to show how catalase breaks down hydrogen peroxide.
J
Some enzymes can break down large molecules,others can build them up.
J
Carry out an experiment to see how quickly amylase can break down starch.
J
All enzymes are proteins.
J
J
Follow the course of an enzyme-controlled reaction as shown by a graph.
Each enzyme controls one particular reaction.
J
J
Plan an investigation into the effect of temperature on the action of an enzyme.
Enzymes can be used again and again.
J
J
Eachenzymehas an optimu optimum m temperature and is denatured by boiling.
Carry out an experiment to see the effect of pH on the action of a protease.
J
J
Most enzymes have an optimum pH and are affected by changes in acidic or alkaline conditions.
Interpret a graph showing the effect of pH on enzyme action.
J
J
Carbohydrases break down carbohydrates. Proteases break down proteins. Lipases Lipas es brea break k down fats.
Carry out an experiment to show how starch molecules can be built up from glucose molecules.
J
J
Use immobilised yeast enzyme to break down sucrose to simple sugars.
Immobilised enzymes are ‘fixed’ to small resin beads. They enable the enzyme to be used again and again.
J
Plan an investigation into the action of biological washing powders.
J
Use ectin ectinase ase enz
By collec collectin ting g the Check Checklis lists ts (and (and Revisi Revision on Quizz Quizzes) es) your your st stud uden ents ts can can build build up th thei eirr own own Revi Revisi sion on Book Book..
© Gareth Gareth Willia Williams, ms, 2011 2011
e to to extrac extractt juice juice from
Revision Quiz
1 2 Feeding in plants
As further help for your students when they revise for tests and examinations, we provide a photocopiable Revision Quiz for each chapter. Conscientious students can use it to test themselves by covering up the right-hand side of the sheet, but in any case it provides them with an accurate summary of knowledge even if they have imperfect notes in their exercise books.
Revision
QUIZ
Use these questions to help you revise (cover the right-hand side with a sheet of paper).
1 What do plants need to carry out photos photosynt ynthes hesis? is? (page (page 181)
2 What is the word equation for
... carb on
photos photosynt ynthes hesis? is? (p. 181)
dioxide
variegated ed leaf? leaf? (p. 183) 183) 3 What is a variegat
4 How could you prove that carbon dioxide is needed for photosy photosynthesis nthesis??
... chlorophyll, chlorophyll, carbon carbon dioxide, dioxide, water and and sunlight.
(p. 184) 184)
+water
light and chlorophyll
glucose + oxygen
... a leaf with with some parts parts white where where chlorophyll is missing. ... enclose a destarch destarched ed plant in a plastic plastic bag with soda lime. Leave the plant in sunlight for a few hours. Test a leaf for starch. ... some is used used in respiratio respiration, n, some is
© Gareth Williams, Williams, 2011
Help Sheets and Extension Sheets These sheets are also photocopiable, and include:
pages 120–122
Help Sheet
Hormones
Label the diagram with the name of the hormonal glands using the words in this list: testes testes thyroid thyroid pancreas pancreas pituitary pituitary ovaries ovaries adrenals
● Content Help Sheets Where a diagram in Biology for You You may be too complicated or too time-consuming for your students to draw, we provide a photocopiable version version (at a size suitable for sticking into exercise books).
Some of the diagrams are two-dimensional versions that regularly come up in examination papers, e.g. a section of a leaf and the human digestive system. Students are often asked to label these and extra questions are provided to focus their minds on the diagram. The students’ understanding of the diagram will often be improved if you tell them to colour the key parts (based on colours in Biology for You ).
hormone
gland which secretes it
growth hormone
pituitary
Most of the diagrams from the Pupils’ Book are provided for you to use with a data-projector.
when secreted
other poi nts
when glucose level rises in the blood
Some other Content Help Sheets may introduce a different slant on some of the work covered in the students’ book. This encourages them to apply their knowledge to a new situation.
adrenal ine
prepares body for ‘fight or flight’
thyroid
You may find many of the Content Help Sheets useful for homework or for work when staff are absent.
sex hormones
controls development of sex organs
OHP Sheets There are a number of sheets for making overhead projector transparencies. transparencies. In addition, many of the Content Help Sheets are suitable (enlarged) to make OHP transparencies transparencies to support and facilitate your teaching. If you have a data-projector, these OHP sheets are extended by the Power Point presentations also provided.
Further Content Sheets These sheets are used to take a topic further. For example, ‘Black panthers and leopards’ is a more demanding genetics cross and ‘Caterpillars’ conquest’ gives an in-depth example of biological control.
Investigation Help Sheets A number of Investigation Help Sheets are provided, from which you can select the investigations that you want your students to tackle. The format of these sheets is based on the one used very successfully successfully in the Spotlight Science Science scheme for Key Stage 3. You have the choice of providing your students with j ust the opening description of the task or the full sheet with its ‘Think about ...’ section of hints and tips. ti ps.
Many of the Further Content Sheets include comprehension exercises and provide a useful homework resource.
●
●
Step-by-step Experiment Sheets Where an experiment described in Biology Biology for You may need further support, we provide a Help Sheet to give the student more guidance. A visual impression is given of each stage in the experiment. This step-by-step approach is presented as a ‘flowdiagram’ of the experiment. Students often find it easier to follow an illustration than a set of instructions. Many of these Step-bystep Experiment Sheets include a table that students can copy and fill in with their results. Some questions are included at the bottom of the sheet to re-inforce points from the experiment.
●
© Gareth Williams, Williams, 2011
●
Changing Ideas Sheets These extension sheets (marked with a in the topic Maps) require the students to research an idea (in Biology Biology for You You or elsewhere, perhaps the Internet). Developing comprehension comprehension skills and other aspects of literacy, these sheets are useful as a homework resource.
●
There is a summary of all Help and Extension Sheets on the next six pages.
“Teacher-Map” outline of the chapter For each chapter in the pupils’ book we provide a t opic outline, which gives you an overview of the work covered, and shows you the sequence of concepts on a Topic Map; this gives you a quick visual summary of each topic.
Map Controlling conditions Definition of homeostasis Nature of feedback ■ OHP Sheet Outline of control systems
Icons on the Map indicate: Opportunities for using ICT (see “Using computers and ICT with Biology for You”) Opportunities to discuss how scientific ideas have changed over time (see “How Science Works: Changing ideas” Opportunities for developing Key Skills (see “Key Skills Opportunities”) You can produce a very useful staff booklet by:
• Editing these sheets against your particular
examination syllabus, and putting a line through unwanted sections. You will find it very helpful to visit www.biologyforyou.co.uk • Using highlighter pens to colour-code key items (e.g. essential experiments, optional experiments, work to be attempted only with more-able groups, etc.) • Adding an indication of timing (e.g. a marker of where the class should be by half-term, Christmas, etc.) • Stapling the sheets into a booklet as a useful working document or visual Scheme of Work. Ticks (plus dates?) can be used to keep a record of progress.
l
.
© Gareth Williams, 2011
Controlling blood sugar Role of insulin and glucagon ■ OHP Sheet Diabetes ■ Further Content Sheet
Controlling body temperature Warm-blooded and cold-blooded Skin structure ■ Content Sheet Reaction of skin to overheating and overcooling ■ OHP Sheet, Content Sheet Hypothermia
Excretion and the kidneys Nature of excretion and deamination Urinary system ■ OHP Sheet, Content Sheet Inside the kidneys ■ Content Sheet Nephron structure and function ■ Content Sheet, 2 OHP Sheets
Controlling body water Osmoregulation by kidney Control by ADH ■ OHP Sheet Kidney dialysis machine Kidney transplants ■ OHP Sheet, Further Content Sheet
illi
“Student-Map” for each chapter
Map
The Topic Map is also provided in very large type, so you can make an OHP transparency from it or use it directly on your dataprojector. It can also be enlarged to make a wall poster. We believe students’ learning is enhanced if you can make it less of a ‘magical mystery tour’, by using the Map:
• at the start of the lesson, to remind them of what they did in previous lessons in this topic, and to give them an outline of today’s ‘territory’,
• at the end of the lesson to summarise and remind
them of what they have experienced and learned today, and what to look forward to in the next lesson.
You can also use it as part of a Revision Programme. For example, by covering the OHP transparency with a sheet of paper (so that you can read it, but the class cannot) and then phrasing a question to the class based on each OHP statement. For example, on the third OHP sheet, you could ask ‘ What affects the action of an enzyme? ’ and then when the class respond (or write down their answer) you can reveal the relevant lines t o give instant and effective positive feedback and reinforcement. You could use this method for a quick test at the end of each chapter.
© Gareth Williams, 2011
Homeostasis means keeping conditions inside the body constant. Conditions include temperature, blood sugar, water, pH and carbon dioxide. Homeostasis uses feedback.
Insulin lowers blood sugar by changing glucose to glycogen. Glucagon raises blood sugar by changing glycogen to glucose. Diabetics do not produce enough insulin. They may have to inject extra insulin.
The skin helps keep our temperature constant. Blood vessels and sweat glands can act to increase or decrease heat loss from the skin.
The kidneys remove chemical waste from the body. Nephrons filter these chemicals out of the blood. The blood reabsorbs any useful chemicals. The kidneys get rid of excess water from the body. ADH controls the amount of water in the urine. A kidney dialysis machine filters the patientʼs blood.
B Help and Extension Sheets Chapter
Students’ page
1
8 8 9 9 10 14
Using the microscope Parts of the microscope Looking at plant cells Looking at animal cells Specialised cells How to get the most dye out of beetroot cells
17 18 18 19 20
The rate of diffusion A model cell Osmosis Osmosis in potato cells The effects of sugar solutions on potato cells
29 30
The effect of amylase on starch What effect does temperature have on the action of an enzyme? The effect of pH on the action of a protease The action of protease on protein Building starch from glucose Changing sucrose into simple sugars Comparing the action of biological and non-biological washing powder To find out the effect of temperature on biological washing powder
2
3
31 31 32 33 34
34
4
43–5 43 46 47 50 51 51 54 54 55 55 55 55 56 57 57 57 58
Title of sheet
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
Food tests Ideas about proteins Measuring the energy in a peanut Recommended daily amounts of nutrients Starvation Estimating vitamin C Ideas about vitamins Digestion of 3 types of food molecules by enzymes Assimilation Inside a tooth Fluoride fights tooth decay Teeth Tooth decay What affects how quickly rennin clots milk? The action of lipase on milk fat Your digestive system Human digestive system Making a model gut
© Gareth Williams, 2011
Chapter
Students’ page
5
63 65 68 66 68 69 69 70 70 71 72 72 73 73 73
6
79 80 80 80 81 81 81 82 82 85–86 87–90 91
7
97–8 98–9 100 101 101 102 102 103 103 103 104
Title of sheet
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
Measuring the heat energy from germinating seeds Composition of inhaled and exhaled air Your breathing system Respirometers Your breathing system Breathing in/Breathing out Breathing movements Respiratory surfaces Gas exchange at the alveolus The depth of breathing Artificial respiration What effect does exercise have on breathing rate? What increases the rate of respiration? Fermentation What makes dough rise faster? Circulation of blood through veins, arteries and capillaries A double circulation Circulation of blood through heart and body Ideas about blood circulation Blood vessels What effect does exercise have on pulse rate? Presenting results and looking for patterns Your heart Section through the heart Stents and ECGs Blood cells Lymph and lymphatic system Control of body temperature/ Control of blood sugar Control of blood sugar level Your skin How the skin reduces heat loss/ How the skin loses heat How skin reacts to overheating and overcooling Your kidneys The excretory system Inside the kidney/How do nephrons work? Structure of a nephron How a nephron filters ADH control of body water
© Gareth Williams, 2011
Chapter
Students’ page
7 (cont.)
105 105
8
110 113 113 114 114 114 117 117 120–22 120 123 124 124
9
10
132 132 132 133 139 139 139, etc. 142 142–6 144 147–9 149 150 154
11
161–3 161–3 162 164–5 164
12
182 184–5 184 184 185 185
Title of sheet
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
A kidney dialysis machine The kidney dialysis machine Neurones A reflex arc A reflex arc Testing your reflexes Measuring your reaction time A reaction timer Inside the eye Inside the eye Hormones Chemicals in cows The menstrual cycle The menstrual cycle Control of the menstrual cycle The human skeleton The human skeleton (with labels) The vertebral column Joints in the body Louis Pasteur Robert Koch Diseases An infectious disease Barriers to pathogens Spread of disease: the dirty shop Immunity and vaccines The spread of disease The discovery and development of penicillin Sexually transmitted diseases Effects of drugs and solvents Effects of drugs and solvents (answers) Heroin The effects of alcohol on the body Alcohol in the blood Testing a leaf for starch Factors affecting photosynthesis To find out if light is need for photosynthesis Testing leaves for starch Collecting oxygen gas during photosynthesis Oxygen production during
© Gareth Williams, 2011
Chapter
12 (cont.)
Students’ page
188
187–9 189 189
190 190 190, 192 192 196 183, etc. 197–8
13
203 204 203 204 205 205 206 206 207 207
14
216 216 216 216–17 217 217 217 217 217 217 217, 235 218 218 219 220, 259
15
225
Title of sheet
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
photosynthesis What effect does temperature have on the rate of photosynthesis? Factors affecting the rate of photosynthesis Photosynthesis and carbon dioxide What effect does carbon dioxide have on the rate of photosynthesis? Inside a leaf Section of a leaf Leaf structure Photosynthesis and respiration The grass house Crop production Phototropism in a shoot/Geotropism in a root 3-D diagrams of a root and a stem A potato osmometer Absorption by roots Up the stem To show transpiration takes place Transpiration and the effect of the wind Effect of temperature, humidity and wind on rate of transpiration Factors affecting the rate of transpiration The potometer What affects the rate of transpiration? The male reproductive system The female reproductive system Fertilisation and implantation How animals reproduce Male and female gametes and Sexual intercourse Pregnancy Ante-natal care and birth Methods of birth control More birth control methods The placenta Fertilisation and seed formation Cloning in plants Cauliflower cloning Dolly the first cloned sheep Designer babies A leaf key
© Gareth Williams, 2011
Chapter
Students’ page
15 (cont.)
225 225 225 225 226 227 235 235 235 235 235 235 235 235 235 235
16
240–41 241 241 243–4 243 244 245 246 246 250 251 251–2 251–2 251–2 251–2 254 254–5 254–5 258 240, etc. 261 261
17
266–9 266–9 266–9 266–7 266–7 269
Title of sheet
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
An arthropod key A parasite key Making a key A key to identify animals The animal kingdom The plant kingdom/The other three kingdoms Flowering plants Flower structure Pollination 1 Pollination 2 Fruits and seeds Germination Different pollen Pollination The late-flowering magnolia To see what affects the way seeds fall
A design for life Building a DNA strand A DNA model The structure of DNA Rosalind Franklin Stages in mitosis Stages in meiosis Inheritance of sex Sex linkage Inheritance of eye colour A genetic cross Black panthers and leopards Punnet squares A monohybrid cross in the fruit fly Codominance Haemophilia Genetic diseases The inheritance of cystic fibrosis and Huntington’s disease Selective breeding Genetics and society For GM Foods Against GM Foods
Jean Baptiste Lamarck Charles Darwin Alfred Russel Wallace How do species change over time? Species and speciation The peppered moth
© Gareth Williams, 2011
Chapter
Students’ page
Title of sheet
17 (cont.)
269 270–71
The brown-lipped snail Fossils
18
283 286 288 288 288 289 289 282–8 293 298 298 288 289 289 289 289 288
19
303–4 308–10 309–10 309–10 311 313 313 314 314
20
320 324–5, 336 326 326–7 327 328 328 328 328
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
Environmental factors in a wood The growth of a yeast population Using a quadrat What affects the size of a duckweed population? Sampling techniques Sampling animal populations Collecting invertebrates Charles Elton Adaptations of plants to different environments Predators and prey Predator–prey cycle Looking at samples sizes – fieldwork Identifying invertebrates in leaf litter Identifying invertebrates in grassland and in bushes Identifying invertebrates in grassland and in bushes Identifying freshwater invertebrates Identifying weeds on playing fields
Food chains and food webs Energy flow through a food chain Energy flow through an ecosystem Energy flow through a meadow The water cycle The carbon cycle The carbon cycle The nitrogen cycle The nitrogen cycle
World food supply Different types of pollution Poison algae Rachel Carson Caterpillar’s conquest Sewage treatment 1 Sewage treatment 2 Sewage pollution The effects of sewage pollution on a river.
© Gareth Williams, 2011
Chapter
Students’ page
Title of sheet
20 (cont.)
329 330 186, etc. 336
Against rainforest clearance For rainforest clearance Conservation For and against the use of fertilisers
21
348 350 353 358
Growing bacteria on an agar plate Sour milk An industrial fermenter Mycoprotein production
361
What conditions do woodlice prefer? Sample sizes in biological work How do blowfly larvae respond to light?
22
361 361
Content Use for Investigation Step-by- Further Help OHP Help Sheet step content Sheet Experiment Sheet
© Gareth Williams, 2011
Technician Cards
Experiment 5.1
page 63
Measuring the heat energy from germinating seeds (Worksheet, page 119 )
As an aid to technicians as well as teaching staff, we provide a complete set of Technician cards, one for each experiment in Biology for You. See pages 373–404. They include essential Health and Safety Advice and CLEAPSS reference numbers, for you to use as well as Technicians. They can be photocopied on to card, or printed from the CD, perhaps with different colours as in the Biology for You Contents pages.
© Gareth Williams, 2011
per group: 2 thermos flasks 2 temperature probes Interface Computer with data-logging software Cotton wool 2 retort stands, boss-heads and clamps
• • • • • •
with access to: Surface-sterilised peas that are germinating Surface-sterilised peas that have been boiled and cooled. (You can surface sterilise seeds in 1.0% sodium chlorate(I) (hypochlorite) for 10 minutes then rinse 3 times in clean water.)
• •
New Biology for You Nelson Thornes Ltd
Biology for You Safety, refs:
Technician Card
CLEAPSS 1538, 1550, Hazcard 89,
Recipe card 62 Notes: Seeds sold for planting purposes will probably be coated in a pesticide. Use peas or mung beans sold for food purposes if at all possible. Otherwise wash hands carefully with soap and water after handling seeds for planting. The seeds should be surface sterilised in 1.0% sodium chlorate(I) (hypochlorite) for 10 minutes and then rinsed 3 times in clean water. This should prevent unwanted fungal growth during the experiment. Remember the disinfectant is corrosive at this concentration. Wear eye protection. Visual aids available:
© Gareth Williams
Information and Communication Technology There are many opportunities in Biology to support your teaching with ICT, and we include a section giving suggestions for using ICT with Biology for You. See pages 18–26. A list of ICT resources and contacts is given on page 27. The Map for each chapter shows these opportunities by a icon.
Answers to Further Questions Biology for You includes over 200 questions. In the Support Pack we provide detailed answers to all the GCSE questions. These answers, with a mark scheme, are written by a Chief Examiner, and are available for you to photocopy to help your students gain a clearer understanding of what the examiners expect.
Examination Questions and Model Answers We also provide some photocopiable GCSE questions, each set out as on an examination paper, with a photocopiable Mark Scheme and ‘model’ answers. See pages 49–67. These questions are chosen for their wide-ranging cross-topic content, and are particularly useful in the revision period before the final examination – if used earlier, they may appear too daunting.
Website Support Much the easiest way to see which pages in Biology for You are needed for your particular specification is to download the relevant pdf file of page references for your chosen Examination Board, from: www.biologyforyou.co.uk Photocopying and distributing this document to your pupils for the revision period should help to focus their minds on the task of preparing adequately for their examination.
© Gareth Williams, 2011
Answer 2
This Examination Question covered work on: • efficiency of energy transfer (p. 310) • intensive food production (p. 316) • transgenic animals (p. 257)
Answers
Marks
Exam Question
Notes and Hints
(a)
1 mar k for 4%
1
It is a good idea to bring a calculator into the examination with you to give you confidence with calculation questions. Sometimes you are asked to show your working which is worth doing because marks are available for working even if you get the wrong answer. However, this is not asked for in this question. The percentage symbol is needed in the answer so don’t forget units when you answer this type of question.
(b)
It becomes the energy source for decomposers
1
‘Suggest’ questions are asked when the examiners feel that you ought to be able to work out the answer using your knowledge and understanding of the underlying principles of the information e ar and to ‘ ’
How Science works : Changing ideas The Programme of Study for Science in Key Stage 4: ‘How Science works’ states: Pupils should be taught: 1b
how interpretation of data, using creative thought, provides evidence to test ideas and develop theories,
1c
how explanation of many phenomena can be developed using scientific theories, models and ideas,
1d
that there are some questions that science cannot currently answer, and some that science cannot address,
3a
recall, analyse, interpret, apply and question scientific information or ideas,
4a
about the use of contemporary scientific and technological developments and their benefits, drawbacks and risks,
4b
to consider how and why decisions about science and technology are made, including those that raise ethical issues, and about the social, economic and environmental effects of such decisions,
4c
how uncertainties in scientific knowledge and scientific ideas change over time and about the role of the scientific community in validating these changes.
The Examination Boards have interpreted these statements in slightly different ways, so you will need to look carefully at the specification you are using. The grid lists a number of topics collected from the various examination specifications, with:
• •
references to chapters and page numbers in the Students’ Book, references to supporting worksheets, where they are available.
Each of these topics is marked with a for each chapter.
icon on the relevant topic map
© Gareth Williams, 2011
How Science works : Changing ideas Possible opportunities
Chapter
How Science works
Students’ page
Page
373–82
Ideas about proteins and vitamins
4
43, 51, worksheets (2)
Ideas about blood circulation
6
80, worksheet
Use of hormones to control fertility
8
125–6
Work of Pasteur and Koch on microbes and disease
10
139, worksheets (2)
104, 109 144
199, 200
Living conditions and life-style and the spread of disease
143–4 worksheet
204
The discovery and development of penicillin
150, worksheet
207 214
The effects of cannabis on the body
11
162, worksheet
Link between smoking tobacco and lung cancer
11
166–7
Crop production: management and distribution
12
183–99, worksheet
238
Plant tissue culture
14
218, worksheets (2)
260, 261
Cloning Dolly the sheep
219, worksheet
Moral and ethical arguments for and against human cloning
220
Economic, social and ethical issues of cloning and genetic engineering Ideas about DNA
262
14, 16
234, 256–9, worksheet
297
16
241–3, worksheets (3)
282–84
Rosalind Franklin
243, worksheet
Mendel’s ideas and their recognition Ideas about genetically modified foods
247 261, worksheets (2)
298, 299
Fossils as evidence for evolution Over-use of antibiotics and resistant bacteria Jean Baptiste Lamarck Darwin’s theory of evolution Alfred Russel Wallace
17
Charles Elton
18
282–98, worksheet
Factory farming
19
316
Aspects of an increasing world population Conservation Rainforest clearance Rachel Carson Biological and chemical methods of pest control Eutrophication
20
320–21 334–5, worksheet 329, worksheets (2) 326–7, worksheet
355 353, 354 348
326–7, worksheet 326, worksheets (2)
349 351, 352
Food supplements Medicinal plants
21
© Gareth Williams, 2011
270–71, worksheet 268 266–9, worksheets (2) 266–9, worksheets (2) 266–9, worksheet
285
354–5 357
311 306, 308 306, 308 307 322
Key Skills opportunities The Key Skills Qualification requires students to show evidence of achievement in the Key Skills of:
● Communication, ● Application of Number, ● Information Technology. GCSE students will normally be aiming at Level 1 or Level 2, and looking for evidence to present in a portfolio from all the subjects that they study. In summary, the components at Level 2 are:
Communication ● Contribute to a discussion. ● Give a short talk. ● Read and summarise information. ● Write different types of documents. Application of Number ● Interpret information from different sources. ● Carry out calculations. ● Interpret results and present findings. Information Technology ● Search for and select information. ● Explore and develop information, and derive new information. ● Present combined information. More information is given on pages 392–3 in the Students’ Book and full details of each component can be found at: www.qca.org.uk About 35 opportunities for developing these Key Skills are marked with a icon on the relevant topic map for each chapter.
© Gareth Williams, 2011
Acknowledgements Acknowledgement is made to the following Examining Bodies for permission to reprint questions from their examination papers: EDEX Edexcel Foundation OCR
Oxford, Cambridge and RSA Examinations
AQA
Assessment and Qualifications Alliance
Acknowledgement is also made to the following for various articles: The Daily Telegraph page 263 The Guardian page 348 Illustration acknowledgements Ann Ronan Picture Library: p.305; Bodleian Library: p.322; Bridgeman Art Library: p.199 (Edelfelt, Gustaf Aristides (1854–1905), Musee D’Orsay, Paris, France; Corbis: p.331 Hulton Archive: p.207 (Chris Ware, Keystone, Getty Images); Mary Evans Picture Library: pp.109 (Portrait by A Bortzells Tryckeri, Stockholm, in Nobel, 1929), 200 (from a photograph by Frank Hancox reproduced in the Illustrated London News (1897), 307 (photo by Reginald Haines reproduced in Bibby’s Annual ), 306 (unattributed photograph reproduced on a postcard); Parke-Davis: p.144 (1959); Science Photolibrary: pp.104, 285. Picture research by:
[email protected]
© Gareth Williams, 2011
Using computers and ICT in Biology for You There are opportunities for using information and communications technology in Biology for You and this section serves to highlight the best of them. Some of the resources you may well have, others you may consider obtaining and some need only a trip to the Internet to find today’s Biology. The evidence for just how important Biology is has never been so accessible.
Sensors to collect data High on the list of ICT resources are the sensors that link to a computer. A barometric pressure sensor is a surprisingly versatile device. This sensitive pressure sensor responds to slight changes at normal pressures and can be used in experiments on osmosis and transpiration. It is sensitive enough to act as a respirometer and a potometer allowing some very slow and small changes to be recorded over time. The key to success is to ensure an air-tight seal and minimal dead space in the tubing. Two popular sensors include those that respond to pH changes and oxygen levels. A pH electrode allows you to record the change as lipase digests fat into fatty acids. An oxygen electrode, together with a light sensor, allow you to monitor changes in an aquarium over several days. Using either successfully nearly always arises from careful storage of probes. Having a spare probe, though extravagant, helps reliability dramatically.
Multimedia software to visualise and understand Today’s Biology resources must surely include simulation software. There are for example, software titles that animate biological processes such as breathing and the heartbeat. In making recommendations we have selected those that help students’ understanding. You can often find useful short animations hiding in other multimedia titles about the human body, in ‘electronic’ encyclopaedias and by searching for ‘carbon cycle animation’.
Information sources Information sources like encyclopaedias and the Internet have a secure place in finding facts and relevance. You will find text and pictures that go beyond a book – including science news, current health ‘scares’ and much to complement the Biology at Work sections. Think of an industry
where Biology is at work and for sure there exists a press release, a point of view and an alternative point of view. Use of the Internet is highly recommended for giving knowledge the relevance that students thrive on. Use it for interest, homework and projects. Use it too for end-of-topic revision, see, for example, BBC Bitesize at www.bbc.co.uk. We have provided links to places that caught our interest and your own searches will surely find more.
Handling data A spreadsheet program is a helpful tool. It lets you record results do calculations and draw graphs deftly. With just a bit more effort it lets you do the maths required to model a food chain, or show what we mean by exponential growth. Having everyday convenient access to a spreadsheet program really helps. Use it as a recording table and a graphing program. Use it to help answer the questions at the end of each chapter .
Display technologies When there are specimens, techniques and much more to observe in Biology for You, display technologies will add to students’ experience. Core items are cameras on desk stands variously called ‘visual presenters’ or ‘document cameras’. They plug into a PC, projector or television so that all can see a front bench demonstration or even a page from a book. Use an adaptor to connect it to a microscope and create an experience to share. Having the means to capture, photograph and video what you see opens the door to using images in worksheets, project work, and labelling exercises. One could for example, video a demonstration as it happens, play it back and then ask the class to recreate the commentary. Digital microscopes share many of these features. Interactive whiteboards, which turn a screen into a space where you can click, draw and store work will surely find use in Biology. They help with diagrams and labels in particular. You could, for example, project a photograph of a plant cell and then use the ‘whiteboard’ software to label the parts. You can trace around objects and make diagrams on screen. The connection between photographs and diagrams is easily shown. Display technologies make your resources large and graphic. There may be no going back to the old ways. Roger Frost, IT in Science consultancy and training Email:
[email protected] Web: www.rogerfrost.com
© Gareth Williams, 2011
Cells and life processes
Osmosis in plant cells
Chapter 1 Cells Specialised cells
For hands-on or demonstration uses, Cells (from Sunflower Learning) offers photomicrographs of most of the examples needed at this level. Usefully and unusually each image will ‘dissolve’ into a labelled diagram. Cells are the speciality of an Internet site (www.cellsalive.com), which can provide visuals and animations for this topic. The site has photomicrographs of specialised cells that can, say, be placed on PowerPoint slides, labelled and used for discussion. If you have it, Images of Biology (Nelson Thornes) is an Advanced Level title with many video clips and photomicrographs of different types of cell that will be useful in this chapter. Also Bioscope for Advanced Level (Cambridge–Hitachi) offers a ‘virtual microscope’ with sample slides. A fun ‘virtual microscope’ can be found at the University of Delaware www.udel.edu. Cell size
A spreadsheet program can show the relationship between surface area and volume; try this particularly if you have a display screen. First make a spreadsheet table like the table shown on page 12 in the students’ book, but let the program do the calculations. Show how changing the area of one cube face affects the volume and surface area. For example, double the area of a cube face and see how the volume changes in relation to this. Highlight the volume and area values and plot one against the other on a graph. Plant organs
Use a microscope with a camera attachment to show the specimens on a display screen. This or a digital microscope will allow you to take photographs of your specimens. Cells (from Sunflower Learning) offers ready-made examples.
Chapter 2 Diffusion Diffusion
The simulation software Diffusion (from Sunflower Learning) and Diffusion and Osmosis (from Plato) offer the opportunity not only to visualise these processes but also to investigate them. The students see a membrane with solvent and solute particles on each side of it. They can change concentrations and they can change the size of the pores in a membrane. The simulation shows the particles in motion and allows you to simulate the diffusion of a smell, the passage of materials in a root hair and across the gut membrane.
You can use a barometric (ie. sensitive) pressure sensor to monitor volume changes in osmosis experiments. This method allows you to compare the rate of osmosis between different liquids. The set-up is outlined in Experiment 2.3 and the Questions section. One group can use this set-up at the start of the lesson as the class use the manual method. Connect the pressure sensor to Visking tubing filled with sugar solution. A line graph shows the progress of osmosis over time. If you have a display screen Plants (from Sunflower Learning) features photomicrographs and animation of water transport in plants.
Chapter 3 Enzymes Breakers and builders
Very effective animation of how an enzyme works can be seen in Enzymes (from Sunflower Learning). It shows well how an enzyme is not used-up and also why enzymes control one particular reaction. Also here, and useful for the next section, is a virtual lab where pupils can investigate changes in pH, temperature and concentration. For an explanation of enzymes see www.howstuffworks.com. The fastest enzyme in the west!
The heat from the breakdown of hydrogen peroxide assisted by catalase is considerable. This change can be monitored using a temperature sensor and visualised on a graph. It is surprising how high a temperature this reaction can reach. You need a couple of temperature probes placed in test-tubes, each containing hydrogen peroxide. Start recording and add a piece of potato to one and chopped potato to the other, and then note the change as two traces find their way up the screen. The method lends itself well to an investigation into enzyme activity. Hotting up
Enzyme experiments can be monitored using computer sensors, giving the advantage of showing a rate of change. You can record the rate at which amylase acts on starch by measuring the light level using a light sensor. The rate of the reaction shows as the slope of a graph on screen. You can monitor how fast lipase turns milk fat into fatty acids. Place a pH electrode into a mixture of milk and lipase, add sodium carbonate to make this slightly alkaline and then place in a water-bath. The pH should decrease over the next half hour. Visit the National Centre for Biotechnology at www.ncbe.reading.ac.uk for a suitable source of lipase and other enzymes. Enzymes and pH
The enzyme simulation Enzyme Lab (from Newbyte) as well as Enzymes (from Sunflower
© Gareth Williams, 2011
Learning) offer the ability to change all kinds of variables in software and to see the results on a graph. Here you might show what affects enzyme reactions graphically and efficiently look at a variety of parameters in one session. Enzymes in industry
For project work, take a look at the fascinating uses of enzymes in industry. Visit Novozymes at www.novozymes.com to find first-hand information.
Humans as organisms
5.7. By using the very sensitive barometric pressure sensor in place of a capillary tube, you can obtain better precision and a more graphic result. Two-way trip to your lungs
For animation to illustrate the process of breathing see Breathing and Respiration (from Plato). Like a live textbook diagram, here are close-ups to use to explain breathing. This includes animated cameos of the action of the diaphragm, gas and blood flow in the lungs, alveolus, heart and muscles. Controls within the software allow you to see the effects of exercise. Deeper into your lungs
Chapter 4 Food and digestion Food and energy
You can use a temperature sensor in Experiment 4.5 to measure the temperature rise as a peanut burns. You can see the temperature rise as the peanut burns, and also, interestingly, gain extra precision in your measurement. How much energy?
Diet analysis programs give a detailed breakdown of the nutrients in your diet and show how well your intake relates to the recommended daily amounts. Diet Analyser (from Plato) allows you to do this very efficiently. Use it both to compare the needs of different people and to compare the energy content of different foods. Or more simply, use it to compare the energy content of different take-away meals – the students enter the details for a pizza meal, a burger meal and a fried chicken meal. You may prefer to use a spreadsheet program to calculate the ‘Energy content of different foods’ in this chapter.
Animation is available to teach about what happens in the lungs. Alveolus (from Plato) shows expanding air sacs, gas exchange in the lungs, the diffusion of oxygen and carbon dioxide. These visuals help to show how we move carbon dioxide out of the body and how we obtain oxygen from the lungs. See also Circulation (from Sunflower Learning) which also animates blood flow in the alveoli. Take a deep breath
To examine the effect of exercise on your breathing rate, as in Investigation 5.11, students can use a breathing sensor. They might use a stethograph, which is a corrugated tube that stretches round the chest and transmits chest movements to a pressure sensor. This shows the frequency and depth of breathing. To measure lung volumes and vital capacity, they might connect a position sensor to a spirometer, and the sensor can record the movement of the spirometer lid. Respiration without oxygen
Chapter 5 Breathing and respiration
You can monitor the rise of bread dough, for Experiment 5.13, by resting the lever arm of a position sensor on the surface of the dough. You might set this up alongside the class experiment and review the results towards the end of the lesson. For experiments concerning fermentation, sensors which measure oxygen or pH can be left in the ferment to provide evidence that changes are taking place.
Measuring the heat energy from germinating seeds
Muscles without oxygen
In Experiment 5.1, you can use a sensor to measure the temperature rise as seeds germinate and display this clearly as a graph on screen. A data logger will take readings through the day and night, adding to the precision you could normally achieve in the experiment.
See the animation of oxygen uptake in muscle in Breathing and Respiration (from Plato). This software title also allows you to show the effects of exercise on muscle. See also Circulation (from Sunflower Learning) which also covers this topic.
How fast?
Chapter 6 Blood and circulation
Monitoring pressure changes with a computer not only shows the change but also the change over time. You can make a respirometer with a slight variation of the manual procedure for Experiment
The double pump
Digestion
For animation of what happens in the gut see Digestion (from Sunflower Learning) or Digestive System (from Plato). Ideas such as peristalsis and chemical digestion are clearly shown.
For an animation of the heart showing the double circulation see Circulation (from Sunflower Learning) or Heart (from Plato). Circulation
© Gareth Williams, 2011
features good animation of how muscle assists circulation in the vein.
see how the reaction time improves with practice.
Heart action
Your nervous system
For an animation of the heart showing the heart cycle, see Circulation (from Sunflower Learning) or Heart (from Plato). These titles offer an inside view of the heart, which can be run as slowly as required.
Software titles about the human body have graphics and animation you can show to illustrate reflex arcs. The Ultimate Human Body (from AVP) has a section on the nervous system. The science section of the BBC website www.bbc.co.uk has a nervous system game.
Seeing your pulse trace on the computer screen can be memorable, and various sensors allow you to do this. You will find pulse and ECG sensors which record how the heart responds to, say, caffeine stimulation. Relatively inexpensive sensors can be found in high-street outlets. Heart disease
For information and project work, these websites on health and the heart will be of use: ● at BBC Health see www.bbc.co.uk/health/heart/ ● at British Heart Foundation www.bhf.org.uk see the ‘Heart Health’ section. Your blood Circulation (from Sunflower Learning) contains microscope pictures of various blood cells to help complete the picture of the heart and circulation.
Chapter 7 Homeostasis Keeping things steady
Your senses
Computer sensors such as the light sensor and the sound sensor make interesting analogies to explain how the eye and the ear work. Set up a sensor with a data-logging system and show its response on a bar graph. See also the diagrams and animation at Human Anatomy Online www.innerbody.com. In particular see the ear and eye in a section on the ‘Nervous System’. The science section of the BBC website www.bbc.co.uk has an interactive section about the senses. Correcting eye defects
One of the best explanations of long and short sight can be found in Crocodile Physics (from Crocodile Clips). The optics section in this software has a model eye where you can alter a correcting lens and see where the light rays come to a focus. Ovulation and the menstrual cycle
Electronic control systems are good analogies of human control systems and can be used to demonstrate a point about temperature regulation. The modular microelectronics kits, often used in electronics courses, can be handy here. By connecting together a couple of modules you can quickly make a working model of homeostasis.
For animation showing the cycle, the interplay of hormones and the effect of the pill, see Menstrual Cycle (from Plato). More animation, with a good day-by-day graph can be found at the BBC website. It can be found via a search at www.bbc.co.uk.
Controlling blood sugar
Chapter 9 Support and movement
The software title Blood Sugar (from Plato) shows the feedback loops that control blood glucose. It provides an interactive model of two humans, one normal, one diabetic, and allows you to examine what happens when they eat and exercise.
Joints
For further information about diabetes, its treatment and approaches to its prevention, see BBC Health at www.bbc.co.uk/health/ Inside the kidneys Kidney (from Plato) animates many of the ideas in this section: the flow of salts, the absorption of water and the role of hormones.
Chapter 8 Control and coordination Your reflexes
You can use computer light gates for measuring your reaction time very effectively. You can easily
Your can use graphics and animation about the human body to show the workings of different types of joint. You will find diagrams at Human Anatomy Online www.innerbody.com. (see, for example, the Muscular System). Compare this with www.bbc.co.uk/science/humanbody which has an interactive diagram of the skeleton and muscles.
Chapter 10 Disease Information on health can always be found online, for example, see the section on the immune system at BBC Health www.bbc.co.uk/health. A search at this site yields information on all kinds of disease, while the World Health Organisation at www.who.int has statistics and advice on current pandemics. Photographs and artwork can be found in the library section at The Wellcome Trust
© Gareth Williams, 2011
www.wellcome.ac.uk. See also www.schoolscience.co.uk for information on the history of medicine, diseases, asthma and immunity. For detailed information on the life cycle of the malarial parasite and prevention, treatment and diagnosis of malaria, see for example www.rph.wa.gov.au/malaria.html. See also Access Excellence – the national health museum at www.accessexcellence.org.
stage further by offering controls to change the temperature, the intensity of the light and its colour. Fertilisers
For a homework or revision activity see the fact sheet with questions on the importance of N, P, K in plants at Schoolsnet www.schoolsnet.com.
Chapter 13 Plant transport Transpiration
Chapter 11 Drugs Drugs
The Internet is the first port of call for facts on drugs but steer towards reliable sources such as the National Drugs Helpline known as TalktoFrank www.talktofrank.com. The BBC at www.bbc.co.uk offers drug information on various levels including health, news and crime. Smoking is covered by ASH (Action on Smoking and Health) www.ash.org.uk. See also www.schoolscience.co.uk for information on abused drugs. Smoking and health
To pick up facts about the chemicals in smoke, and their effects on the body, have the class visit this Internet site which you might use for an information-collecting exercise: ● ASH (Action on Smoking and Health) www.ash.org.uk
For animation showing the stoma opening, as well as micrographs of numerous cells, see Plants (from Sunflower Learning). In addition to Experiment 13.3, you can monitor loss in mass using a computer-linked balance. Another reliable approach is to place a plant in a polythene bag with a humidity sensor and see how this changes over time. The method is straightforward and worth a try. Measuring transpiration
A barometric pressure sensor (narrow range pressure sensor) is able to show the effect of wind on transpiration, often with immediate results. It is easy to set up. Also a plant stem can be connected to this very sensitive sensor using a rubber tube; the effect of a desk fan is seen as a trace on a computer screen.
Chapter 14 Reproduction
Plants as organisms Chapter 12 Feeding in plants Raw materials for photosynthesis
For animation of what happens in photosynthesis, as well as micrographs of numerous cells, see Plants (from Sunflower Learning). Animation showing the stoma opening and a cross section of a leaf will be particularly relevant. You can use an oxygen sensor and a light sensor to show how the rate of photosynthesis changes with light level. You might also monitor the light and oxygen levels in an aquarium over several days and look for a pattern between the two measurements. You can use a pH sensor in place of the oxygen sensor – a pH electrode placed near the plant leaves will be sensitive to a local depletion of carbon dioxide during photosynthesis. Sample results are available at www.rogerfrost.com.
Useful here are the diagrams at Human Anatomy Online www.innerbody.com where you might see the reproductive system. Compare this with www.bbc.co.uk/science/humanbody which has an interactive diagram of the reproductive system. Cloning Intensive food production For another viewpoint on food production see Compassion in World Farming www.ciwf.org. Look within to find resources on cloning, genetic engineering and selective breeding. More can be found at Global Change where news, lecture and video can be found in quantity on www.globalchange.com/cloning. This is a fastmoving area of opinion where a search on newspaper sites for ‘cloning’ or ‘cloning links’ yields results.
Chapter 15 Variation Classification
Products of photosynthesis
Software titles can be found that simulate Experiment 12.6, where students watch bubbles appearing from pondweed. Both Photosynthesis (from Plato) and Photosynthesis (from Sunflower Learning) can be used as a follow-up to the experiment either as a demonstration or a class activity. The simulation takes the experiment a
‘Identification keys’ and ‘Identifying organisms’ are simple classification tools that you can use on a whiteboard. They can be found at www.echalk.co.uk. Animals UK (from Gatekeeper Educational) is software to identify common British animals that students might find near school. It features a
© Gareth Williams, 2011
database with 150 species including butterflies, other land invertebrates, pond life, amphibians, reptiles, birds and mammals. Plants UK (from Gatekeeper Educational) similarly features 54 species of wild flower and 64 species of trees, shrubs and grasses. See the Field Studies Council www.field-studiescouncil.org which run field centres around the UK and publish fold-out identification charts. See Biomedia at http://ebiomedia.com for an exercise about Animal Phyla.
Chapter 16 Inheritance
explain genes at www.eurekascience.com. Start with www.dnai.org, which although this is often beyond the syllabus, features stunning animation and video. Search further and you will find academic and everyday applications of genetics, for example, USA Genomes www.ornl.gov/hgmis; Advanced therapies www.celera.com; Watchdog on genetic technologies www.genewatch.org; USA Human Genome Research www.genome.gov; Nowgen Genetics Knowledge Parks www.nowgen.org.uk; European Initiative for Biotechnology Education www.eibe.info.
Chapter 17 Evolution
Mitosis
Having convenient access to video is surprisingly helpful. Mitosis is easily visualised with the help of Mitosis and Meiosis (from Plato). This particular title allows you to run back and forth through mitosis, which helps when explaining the process. That aside, clips of mitosis can be found with a search of the Internet. For example, search at the US Public Broadcasting Service www.pbs.org, School Science www.schoolscience.co.uk or the BBC www.bbc.co.uk for free animation. Another software resource to consider is Mitosis and Meiosis: An Interactive Approach (from Illumination Educational Software) which similarly animates cell division. Meiosis
The software title Mitosis and Meiosis (from Plato) allows you to explain what happens in meiosis. Students can see the process animated clearly, and see the variation that meiosis makes possible. For a class exercise, you might copy the stages of meiosis into PowerPoint slides. The class can sort the slides and annotate them. Genes in action
The software simulation Inheritance (from Plato) ably shows how characteristics are inherited. It allows students to experiment with the inheritance of blood groups, tongue rolling or haemophilia, and to see how the genes pass from parents to grandchildren. The software animates the pairing of genes and offers opportunities to investigate a good range of scenarios. Two titles aimed at Advanced Level are useful if you have them. Drosophila Genetics and Pea Plant Genetics (from Newbyte) simulate almost unlimited experiments with fruit flies and pea plants respectively. Used here, perhaps just as a demonstration, they help make many of the teaching points in this section. Find out about research into the human genome at The Wellcome Trust Sanger Institute at www.sanger.ac.uk. Search the Internet and you can find Eureka Science with an interesting way to
Evolution The BBCs pages on ‘Human Beginnings’ has background material on evolution that students might examine for homework. This is at www.bbc.co.uk/sn/prehistoric_life. Public Broadcasting in the US offers information and a short tutorial on evolution www.pbs.org. Selection in action Selection lends itself well to software models and Natural Selection – Frogs (from Newbyte) involves students in the predation of coloured frogs. They can add a poison gene into the population or introduce frogs that mimic poisonous frogs. The model works as a game to hunt frogs, however the treatment is clever and effective. Another title in this series is Natural Selection – Beetles (from Newbyte) which deals with beetle colours. Peppered moths Natural Selection – Peppered Moths (from Newbyte) puts students in the role of a bird predating upon different moths. As the forest changes through industrial pollution it becomes easier to catch the white moths. As a result students effectively work through the story of the peppered moth. This is another simple but very effective teaching tool. A similar tool to purchase can be found at www.echalk.co.uk.
Living things and their environment Chapter 18 Adaptation and competition How populations grow Predator Prey (from Sunflower Learning) and Creatures (from Future Skill Software), which provide models of foxes, rabbits and plants, would be very useful here. As the model runs you see the number of coloured squares increase and decrease. Parameters such as the level of sunlight and death rate can also be changed. This software can make a good contribution to this section. Also see UK Countryside & Nature Conservation www.naturenet.net; Kew Gardens www.kew.org; WWF www.wwf.org;
© Gareth Williams, 2011
United Nations Environment Programme World Conservation Monitoring Centre www.unep-wcmc.org.
www.learn.co.uk. Another example is at BBC Bitesize www.bbc.co.uk. Intensive food production
Predator–prey cycles Predator Prey (from Sunflower Learning) and Creatures (from Future Skill Software) are both models of foxes, rabbits and plants and are particularly useful here. Several variables can be changed. The software plots a graph to show population changes over time.
Chapter 19 Energy and nutrient transfer
For another viewpoint on food production see Compassion in World Farming www.ciwf.org. Look within the Education section to find resources on ethics and farming, animal sentience, and an ‘eat less meat’ campaign.
Chapter 20 Humans and the environment The greenhouse effect
Pyramids of biomass Predator Prey (from Sunflower Learning) and Creatures (from Future Skill Software), which offer models of foxes, rabbits and plants, are particularly useful here, as the software plots a graph to show population changes over time.
You can also use a spreadsheet program to handle the numbers in a food pyramid. It requires a table with a list of animals (eg. owls and shrews) in the first column and their proportions in the next column (eg. 1, 10). A third column shows their mass, while the last column calculates the total mass. The resulting model allows you to calculate the loss of energy through the food chain. Food webs Students can build food webs from organisms provided at the Gould League ww.gould.edu.au/foodwebs/kids_ web.htm. Food Webs: Ponds (from Newbyte) is an intriguing piece of software that allows you to construct food chains and webs using a set of organisms. You run the model, which can be as simple or complex as needed to see it played out as a graph on screen. All manner of factors, such as phosphate levels, nitrate levels and temperature affect the web. The food web can be adapted to model a local environment.
An animated greenhouse effect with statistics on its impact is found by searching at the BBC News site news.bbc.co.uk. Conservation
Websites of conservation organisations include the following: The National Trust www.nationaltrust.org.uk; The Council for National Parks www.cnp.org.uk; Natural England www.naturalengland.org.uk has information on National Nature Reserves (NNR) and Sites of Special Scientific Interest (SSSI) and Heritage Coasts. The Department for Environment, Food and Rural Affairs’ Farm Woodland Scheme is at www.defra.gov.uk; The Royal Society for the Protection of Birds www.rspb.org.uk.
Biotechnology and behaviour Chapter 21 Biotechnology Biotechnology
Useful stepping stones on the Internet are the European Initiative for Biotechnology Education www.eibe.info and Access Excellence – the national health museum at www.accessexcellence.org. Yoghurt manufacture
Nutrient cycling Carbon cycle Even the slightest amount of animation will help explain the carbon cycle. Search at US Environmental Protection Agency www.epa.gov to find one example. The ‘Ecology’ section at Purchon’s www.purchon.com offers facts and diagrams on the carbon cycle – and much mainstream Biology. A detailed treatment with useful diagrams, for library projects, for example, can be found at Earth Observatory earthobservatory.nasa.gov. Another example is at BBC Bitesize at www.bbc.co.uk. Nitrogen cycle Revision notes about the nitrogen cycle and more can be found in the science section at
Monitoring the souring of milk with a data logger yields results worthy of discussion and is perhaps one of the easiest of procedures to attempt. Place a temperature probe and good pH probe in a beaker of milk, cover with foil and ensure the data logger is powered. Record for up to 48 hours to see how the pH is at first buffered by the milk proteins but eventually changes. Sewage treatment
With biotechnology so per vasive, students can gain a flavour of its many applications through project work on the Internet. Websites of all kinds can be found with a general search. For example, information for a project on water treatment can be found at www.theguardians.com.
© Gareth Williams, 2011
Biofuels
Information on biomass fuel can be found, for example, at US Energy Information Administration www.eia.doe.gov.
www.bbc.co.uk. See also National Geographic at www.nationalgeographic.com. Another springboard to resources is the education section at the US Animal Behaviour Society www.animalbehaviorsociety.org.
Chapter 22 Behaviour Animal behaviour
BBC Science and Nature covers a range of animal behaviour topics in a digestible format: start at
© Gareth Williams, 2011
Resources For sensors and data-logging software: ● Commotion, Commotion House, Morley Road, Tonbridge, Kent TN9 1RA. Tel 01732 773399. Fax 01732 773390. www.commotiongroup.co.uk ● Data Harvest, 1 Eden Court, Leighton Buzzard, LU7 8FY. Tel 01525 373666. Fax 01525 851638. www.data-harvest.co.uk ● Griffin Education, Bishop Meadow Road, Loughborough, Leics., LE11 5RG. Tel 01509 555349. Fax 01509 555200. www.griffin-education.co.uk ● Logotron, Rickett Educational Media Ltd, Great Western House, Langport, Somerset, TA10 9YU. Tel 01458 254750. www.r-e-m.co.uk/logo ● PASCO Scientific, Feedback Instruments Ltd., Park Road, Crowborough, East Sussex, TN6 2QR. Tel 01892 653322. Fax 01892 663719. www.pasco.com www.pascophysics.co.uk ● Philip Harris Ltd, Findel House, Exelsior Road, Ashby-de-la-Zouche, LE65 1NG. Tel 01530 418000. Fax 01530 418268. www.philipharris.co.uk ● RM (Research Machines), New Mill House, Milton Park, Abingdon, Oxon, OX14 4SE. Tel 01235 826000. Fax 01235 826999. www.rm.com Paperware – available from the ASE: Data Logging in Practice: a practical guide to using computer sensors to teach ages 11–18 (ISBN 0 9520257 4 4) The IT in Science Book of Data logging and Control : a compendium of ideas for using sensors in science (ISBN 0 9520257 1 X) The IT in Secondary Science Book of Data logging and Control : a planning guide, with examples, for using IT across the science curriculum (ISBN 0 9520257 2 8)
Software and other support: ● ASE – Association for Science Education, College Lane, Hatfield, AL10 9AA. Tel 01707 267411. Fax 01707 266532. www.ase.org.uk ● AVP – software, School Hill Centre, Chepstow, Gwent, NP6 5PH. Tel 01291 625439. Fax 01291 629671. www.avp.co.uk ● British Educational Communications and Technology Agency, Millburn Hill Road, Science Park, CV4 7JJ. Tel 024 7641 6994. Fax 024 7641 1418. www.ictadvice.org.uk www.becta.org.uk ● Crocodile Clips – software, 43 Queensferry Street Lane, Edinburgh, EH2 4PF. Tel 0131 226 1511. Fax 0131 226 1522. www.crocodile-clips.com ● Roger Frost & IT in Science – training, Russet House, Cambridge, CB2 6RT. Tel 01763 209 109. Fax 0870 7062335. www.rogerfrost.com ● Future Skill Software, P.O. Box 75592, Seattle, WA 98175, USA. www.futureskill.com ● Gatekeeper Educational Ltd (keys), Waldron Down Cottage, Blackboys, Uckfield, TN22 5NB. Tel 01435 862731. Fax 01435 865722. www.gatekeeperel.co.uk ● Illumination Educational Software, 4b Martlesham Crescent, Greasby, Wirral, CH49 3PR. Tel 0151 522 0356. www.illuminationed.co.uk ● Newbyte Educational Software, PO Box 23698, Edinburgh, EH5 2WX. Tel 0131 552 7681. Fax 0131 552 7682. www.newbyte.co.uk ● PLATO Learning (UK) Ltd, Statesman House, Stafferton Way, Maidenhead, Berkshire, SL6 1AD. Tel 01628 588 300. Fax 01628 588 333. www.plato.com ● Sunflower Learning, 35 Weston Road, Thames Ditton, KT7 0HN. Tel 0845 1300 680. Fax 0845 1300 681. www.sunflowerlearning.com
© Gareth Williams, 2011
Answers to Further Questions On the following pages are the detailed Answers and Mark Schemes for each of the Further Questions in Biology for You. The Answers have been prepared by a Chief Examiner using the mark schemes published by each Examination Board. G
You will find these sheets useful when marking the students’ homework, or when going over the Further Questions in class. You may also find it useful to glance at the Answer Sheet before setting homework, to see how much work is involved in answering a question.
G
The sheets are also available for you to photocopy and hand out to the students if you wish (perhaps as part of a Revision Programme). You may need to explain the Mark Schemes to the students, so that they appreciate for example that in some answers the mark is for the idea in their own words (not necessarily the exact words shown) whereas in other answers the number and unit must be exactly correct.
Model Answers We also provide, on pages 49–67, some photocopiable GCSE questions, each set out as on an examination paper, with a photocopiable Mark Scheme and ‘model’ answers. These questions are chosen for their wide-ranging cross-topic content, and are particularly useful in the revision period before the final examination – if used earlier, they may appear too daunting.
© Gareth Williams, 2011
Further questions on Cells and life processes
Cells
ᮣ
1 (a)ii
(b) (i) (ii) (iii) (iv) (c) (i) (ii)
2
(b)
Diffusion
ᮣ
1 mark each for: plant cells have chloroplasts; plant cells have a cell wall ; plant cells have a large vacuole. 1 mark for the idea that it controls the activities of the cell . 1 mark for the idea that it strengthens the cell . 1 mark for the idea that it is where most of the chemical reactions take place. 1 mark for the idea that it controls the passage of substances in and out of the cell . 1 mark for chlorophyll . 1 mark for the idea that it is essential in the reaction ( photosynthesis) which produces food for all animals and plants. Total 9 marks 1 mark each for: E ; I ; A; G ; C ; D; B; F . Total 8 marks
3 (a)
pages 38–9
4 (a)
1 mark for each of the following ideas: water enters; by osmosis; from high concentration of water molecules to low concentration of water molecules. 1 mark for tick in box stating less absorbed and higher percentage increase. Total 4 marks
(b)
5 (a)
(i) (ii) (b)
(c) (i)
(ii) (d)
6
1 mark for each correct pair: B 3 palisade cell C 1 root hair cell D 4 sensory neurone A 2 white blood cell 1 mark each for two ideas: palisade cell – contains chloroplasts for photosynthesis; root hair cell – has large surface area for absorption of water or mineral ions; sensory neurone – elongated shape enables it to carry impulses over long distances; white blood cell – can change its shape to engulf microbes. Total 6 marks
© Gareth Williams, 2011
1 mark each for: yellow or straw colour; blue / black colour. 1 mark for each of the following ideas: starch has been broken down to sugars; which do not react with iodine solution. 1 mark for each of the following ideas: boil the mixture from A with Benedict’s solution; an orange colour would prove the presence of sugars; orange colour. 1 mark for the idea that the amylase is denatured . Total 8 marks 1 mark for each of the following ideas: sea water contains salt ; the salt concentration of the sea water is higher than the cell solution; water moves from a region of high water concentration to a region of lower water concentration; through the partially permeable membranes of the air sacs; by osmosis / diffusion . Total 5 marks
pages 40–41
Further questions on Cells and life processes
7 (a) (i) 1 mark for each of the following: ᮣ a y -axis scale from -10% through 0 to +10% change in mass filling graph paper vertically 9 and an x -axis scale from 0 to 1.5 arbitrary units filling graph paper horizontally ; all points correctly plotted ; line of best fit drawn. (ii) 1 mark for correctly reading the arbitrary unit where the line crosses 0% change in mass. (b) 1 mark for osmosis. (c) 1 mark for the length of the rods. (d) (i) 1 mark for the idea that water leaves the lettuce by osmosis; (ii) 1 mark for the idea that it could be soaked in fresh water . Total 8 marks 8 (a) (b)
1 mark for rises. 1 mark for each of the following ideas: the solution inside the funnel is more concentrated than the solution outside; there is a net flow of water molecules from outside to inside ; through the partially-permeable membrane; due to osmosis. Total 5 marks
Enzymes (a) (i) 1 mark for protease or suitably named protease eg. pepsin / trypsin; (ii) 1 mark for amino acids but peptides, polypeptides or peptones are possible alternatives. (b) 2 marks for all points plotted accurately (must be Ϯ1ᎏ2ᎏ square), deduct 1 mark per error; 1 mark for best fit curve or ruled point-to- point . (c) (i) 1 mark for (pH) 2 or correct reading from pupil’s graph; (ii) 1 mark for stomach. (d) 1 mark for proteins are large / product is small . 1 mark for proteins (may be) insoluble / product is soluble . 1 mark for protein cannot be absorbed / protein cannot enter blood / product can be absorbed / product can enter blood ; or protein cannot pass through gut lining / product can pass through gut lining . Total 10 marks
10 (a) 1 mark for monosaccharide. (b) (i) 1 mark for each of the following: one scale covers half the grid and is linear ; line drawn is straight through all points; axes correct with sucrase concentration as independent variable and time taken to digest sucrose as the dependent variable; 2 marks for points plotted accurately . (ii) 1 mark for each of the following ideas: as sucrase concentration increased, time taken to digest sucrose decreased ; correct reference to numbers in support . (c) (i) 1 mark for idea of near optimum temperature or idea of fair test ; (ii) 1 mark for idea of water-bath. (d) 1 mark for each of the following ideas: time taken will be longer at low temperature; because low kinetic energy or few collisions; time taken will be longer at high temperature; because enzymes are denatured . Total 14 marks 11 (a) (b)
(c)
(d)
© Gareth Williams, 2011
1 mark for enzyme. 1 mark for the lactase can be used many times / the lactase is not lost . 1 mark for the milk product does not contain lactase. 1 mark for idea warm the milk / surround the tube with a heated jacket / similar suggestion. 1 mark for the enzyme / protein is denatured . Total 5 marks
Further questions on Humans as organisms ᮣ
Food and digestion
ᮣ
1 (a) (i) (ii) (iii) (b)
1 mark for 31; 1 mark for obese; 1 mark for 7 kg . 1 mark for each of the following ideas: tall people are heavier than short people; but they may not be over weight . (c) (i) 1 mark for answer between: 64–65 g (ii) 1 mark for idea that Neil’s son is still growing but Neil is not . Total 7 marks
2 (a)
1 2
mark each for: A – gullet ; B – stomach; C – large intestine; D – anus; E – small intestine; F – liver ; (b) 1 mark each for: (i) E ; (ii) C ; (iii) D. Total 6 marks
3 (a)
(i) (ii) (iii) (iv) (b)
4 (a) (b)
(c)
pages 171–2
1 mark each for: beefburger ; 18.0 g ; liver ( or muscle); glycogen. 1 mark for each of the following ideas (to a maximum of 4): vegetable burger has less energy per 100 g; therefore less likely to contribute to obesity ; vegetable burger has less fat ; therefore less chance of fat deposition in blood vessels; vegetable burger has more fibre; therefore lowers cholesterol or prevents constipation. Total 8 marks 1 mark for fatty acids and glycerol . 1 mark for each of the following ideas: emulsifies fats or breaks down large drops into smaller droplets; which increases the surface area of fats; for lipase (or enzymes) to act upon . 1 mark for each of the following ideas: fats may accumulate inside blood vessels; leading to increased risk of heart attack. Total 6 marks
Breathing and respiration 5 (a)
1 mark for each of two of the following ideas: exercise/contraction of muscles uses energy; energy/ATP released by respiration; from glucose/sugar (or equation for respiration could be given); more rapid respiration releases more energy. (b) 1 mark for each of four of the following ideas: increased blood circulation near body surface/skin/reference to dilation of arterioles/vasodilation/increased blood circulation in capillaries (in skin); increased loss of heat from skin surface (by convection); increased production/secretion of sweat; evaporation of sweat takes heat from blood. (Note: Answers may be phrased in terms of ‘excess heat is lost by …’) (c) (i) 1 mark for the following idea: shorter time (faster run) uses more oxygen / longer time (slower run) uses less oxygen. (ii) 1 mark for each of the following ideas: more oxygen; allows faster rate of respiration/needed for more muscle contraction (for faster running); releases more energy. Total 10 marks
6 (a) (b)
1 mark for trachea or windpipe. 1 mark for the idea that the walls are strengthened by rings of cartilage. (c) 1 mark for the idea that the flow of air in and out of the lungs must not be obstructed . (d) 1 mark for each of the following ideas: volume would increase; pressure would decrease. (e) 1 mark for the idea of contraction of diaphragm muscles. (f) (i) 1 mark for 16 (4 ϫ 4); (ii) 1 mark for 3 dm3 ; (iii) 1 mark each for: A and B resting ; C and D jogging ; E and F running hard . Total 11 marks
© Gareth Williams, 2011
page 173 7 (a)
(b) (i) (ii)
(c) (i) (ii)
Further questions on Humans as organisms
1 mark each for two of: ᮣ Blood and circulation bronchitis; 8 (a) (i) 1 mark for 40 ; emphysema; (ii) 1 mark for 3 . lung cancer . (b) (i) 1 mark for transport of oxygen (or transport 1 mark for 2; of some carbon dioxide); 1 mark for each correct row: (ii) 1 mark each for two of the following ideas: CO2 high low; contain haemoglobin (combines with and O2 low high. releases the oxygen, or carbon dioxide); 1 mark for white blood cell ; large surface area / biconcave shape; 1 mark for one of: no nucleus. engulfs microbes; (c) 1 mark for the idea that the carbon produces antibodies to kill microbes; monoxide combines with the haemoglobin produces antitoxins to neutralise microbial so less haemoglobin is available to transport proteins. oxygen. Total 7 marks (d) (i) 1 mark for the idea that red blood cells have no nucleus; (ii) 1 mark for 5 billion (5 thousand million or 5 000 000 000); (iii) 1 mark each for the following steps in the calculation: 1 cm3 contains 5 billion (see working above) so 5000 cm3 contain 25 thousand billion; but average life of a red blood cell is about 100 days, so average number of red blood cells that have to be made each day is 0.25 thousand billion. (Note: It would probably be easier to convert this to powers of 10, to handle all the zeros ie. 0.25 ϫ 1012.) (e) (i) 1 mark for each of the following ideas: bone marrow from near relative is more likely to be of same tissue type; more compatible or not generate an immune response; (ii) 1 mark for each of the following ideas: this would prevent phagocytes attacking; engulfing the foreign cells. (f) 1 mark for each of the following ideas: reduce chance of infection; needs time for immune system to re-establish. Total 16 marks
© Gareth Williams, 2011
Further questions on Humans as organisms
pages 174–5
1 mark each for: ᮣ Homeostasis axes labelled correctly; 12 (a) 1 mark for each of the following ideas: all plotted correctly; increased ; (b) 1 mark for each of the following ideas: rate of respiration. increases with age up to 64; (b) 1 mark for each of the following ideas: then drops with age. much of the energy released during (c) 1 mark for each of the following ideas: respiration is released as heat ; rapid increase; which causes the body temperature to higher than men; increase. reasonable suggestion eg. caused by (c) 1 mark for the idea that a regulatory menopause. method, eg. sweating, is switched off by the (d) (i) 1 mark for idea of restricting blood flow; change in body temperature which it brings (ii) 1 mark for idea of stopping blood flow to about . heart muscle; (d) 1 mark for each of the following ideas: 1 mark for consequence eg. less oxygen to it is converted to glycogen; heart muscle. which is stored in the liver or muscles . Total 10 marks (e) (i) 1 mark for each of two of the following ideas: 10 (a) 1 mark for each of the following ideas: insulin is produced by the pancreas in advantage is less drugs needed; response to the increased blood sugar level as less chance of rejection; after each meal ; disadvantage is it needs a power supply; this insulin is then destroyed by the body ; and may be larger than normal heart . the single dose would be effective for one or (b) 1 mark for each of the following ideas up to two meals only . a maximum of three : (ii) 1 mark for each of the following ideas: transport problems over a large distance; either lower blood sugar as a result of may find out that it is available too late or exercise; heart must be transplanted quickly; would lead to a decrease in insulin may be too ill for surgery; production. heart may not be the correct tissue type . or lower blood sugar as a result of exercise ; (c) (i) 1 mark for each of the following ideas: would lead to an increase in glucagon 1 mark for good argument for eg. saves production. lives; Total 11 marks 1 mark for good argument against eg. is the 9 (a)
donor beyond help; (ii) 1 mark for good explanation either for or against eg. more donor organs would become available; 1 mark for choice made for or against . Total 11 marks
11 (a) (b)
(c)
1 mark for 84. 1 mark for the idea that his pulse showed the smallest increase during exercise. 1 mark for each of the following ideas: all the students should exercise in the same way ; they measure their pulse more frequently after exercise. Total 4 marks
© Gareth Williams, 2011
pages 175–6 13(a)
1 mark each for: oxygen (left-hand-side of equation); carbon dioxide (right-hand-side of equation). (b) (i) 1 mark for each of the following stages in the calculation: total water gain in one day 2500 cm3 ; total water loss in one day from exhaled air, skin and faeces is 1000 cm3 , so rest lost in urine must be 1500 cm3 (2500 cm3 Ϫ 1000 cm3 ). (ii) 1 mark for each of the following ideas (or the converse arguments): when blood more concentrated (less water in the blood); more water reabsorbed from the kidneys / more water passes from kidney filtrate back into the blood; at collecting duct. (Could also make reference to more ADH / antidiuretic hormone being secreted into blood.) (c) 1 mark for each of the following ideas: urea passes out of blood into liquid (in dialysis machine); by diffusion; concentration of urea in blood falls. (d) (i) 1 mark for each of the following ideas: (transplant is) permanent / long-term; (transplant is) less trouble / avoids need for person to be out of action / avoids need for regular dialysis / etc. (ii) 1 mark for each of the following ideas: possibility of rejection (of transplant tissue); failure of kidney again in future. (Note: Depending on syllabus / requirements, it may be appropriate to award a mark for suitable ethical consideration.) Total 14 marks ϭ
Further questions on Humans and organisms 14 (a) (i) 1 mark for protein; (ii) 1 mark for idea that protein molecules are too large (to pass through walls in glomerulus). (b) 1 mark for idea that water is reabsorbed / passes back from filtrate into blood (so urea becomes more concentrated in the liquid in the bladder). (c) (i) 1 mark each for three of the following ideas: blood passes into dialysis tubing (of dialysis machine); tubing differentially permeable; tubing surrounded by liquid; composition of this liquid is the same as that of blood except there is no urea; urea (plus other waste products) pass from blood to dialysis liquid; by diffusion; along concentration gradient; reference to flow of liquids in opposite directions / countercurrent flow; reference to method of attachment or linking dialysis tubing into blood vessels of person. (ii) 1 mark for concentration of 0.35%; then 1 mark for explanation with the idea that there is then no net flow of salts across the membrane / dialysis tubing (from blood to fluid or fluid to blood) / composition of blood stays the same. Total 8 marks 15(a) (i) 1 mark for hormone; (ii) 1 mark for idea of decrease in water content of the blood ; (iii) 1 mark for in the blood plasma (not just ‘blood’). (b) (i) 1 mark each for any five of the following steps: the water is absorbed into the blood stream ; increasing the water content ; pituitary gland is no longer stimulated ; the production of ADH ceases; ADH is not transported to the kidney ; kidney reabsorbs less water ; (ii) 1 mark for the idea that there will be ADH circulating in the blood plasma / it takes time for this ADH to be used . Total 9 marks
© Gareth Williams, 2011
Further questions on Humans as organisms ᮣ
pages 176–7
Control and coordination 16(a) (b) (c)
(d)
ᮣ
1 mark for reflex arc. 1 mark for the idea of contraction. 1 mark for the idea of less time taken to respond as brain not involved and so less damage likely . 1 mark for each correct answer of D, C and A. Total 6 marks
17(a) (i) 1 mark for each of the following: ‘days’ on the horizontal axis; ‘level of hormone’ on the vertical axis; points joined with suitable lines ; (ii) 1 mark for 58 (units of oestrogen); (iii) (I) 1 mark for oestrogen; (II) 1 mark for each of the following ideas: ovulation occurs around day 14; oestrogen reaches a peak / is highest around day 14. (b) 1 mark each for two of the following ideas: prevent ovulation / contraceptive pill ; stimulate ovulation (in cases of low fertility) / fertility drugs; menstrual problems, etc.; induce birth; hormone replacement therapy (HRT); sex-change treatment . Total 9 marks
Disease 18(a)
1 mark for each of two of the following features: no nucleus or DNA / chromosome / genetic material is free in the cytoplasm; (only) has one chromosome; circular DNA / chromosome; no mitochondria; has a cell wall . (b) 1 mark for each of two of a feature and what it does: white blood cells ingest bacteria; white blood cells produce antibodies / produce antitoxins. Other acceptable answers are: skin – is a barrier to entry / (of bacteria) ; (blood) clotting – is a barrier to entry (of bacteria); tears – kill bacteria / are antiseptic / contain lysozyme; mucus – traps bacteria ; cilia – remove bacteria; stomach acid – kills bacteria / denatures protein / denatures enzyme. (c) (i) 1 mark for kills / destroys bacteria or prevents growth of bacteria; (ii) 1 mark for each of two ideas from: bacteria may be resistant / immune (treatment is futile) or bacteria would not be killed ; may select for resistant type; may cause increased incidence of resistance or penicillin less effective in the future; sore throat may be due to a virus so the penicillin would not work. Total 7 marks
© Gareth Williams, 2011
pages 178–80 19(a)
(i) (ii) (iii) (iv) (b)
20(a)
(b)
(c) (i) (ii)
21(a) (i) (ii)
(b) (i) (ii)
(iii)
(c)
(d) (i) (ii)
Further questions on Humans as organisms
1 mark each for: ᮣ Drugs virus; 22(a) (i) 1 mark for to test for side effects; bacteria; (ii) 1 mark for thalidomide was only tested as a protozoa; sleeping pill ; fungus. 1 mark for thalidomide was not tested on 1 mark for each of the following ideas: pregnant women. blood contains white blood cells that destroy (b) 1 mark for each of five of the following ideas: pathogens (accept idea that blood clots to cannabis is not a pure substance; prevent entry of pathogens); cannabis contains chemicals which might be toxic; hydrochloric acid kills bacteria that enter the patient could become addicted ; with food and drink; cannabis might cause the patient to try other mucus membranes trap bacteria and drugs such as heroin ; prevent entry to lung ; cannabis might have other unwanted side skin acts as a barrier to pathogens . effects; Total 8 marks cannabis is an illegal drug ; cannabis has not been tested in the 1 mark for idea that dirty clothes / laboratory ; equipment / hands / any sensible source any other different valid reason. eg. surgeon, floor passed bacteria Total 8 marks or ease of entry of bacteria during operations. 23(a) 1 mark for each of the following: 1 mark for fewer died ; an x -axis scale from 0–18 litres filling graph 1 mark for an indication of reduced number paper horizontally ; or proportion eg. 20% of previous deaths / a y -axis scale from 0–35 deaths per 100 000 down by 2400 . people per year filling graph paper 1 mark for dialysis (machine) or kidney vertically ; machine; all bars correctly plotted ; (specially chosen kidney) 1 mark for similar bars labelled by country. (b) 1 mark for the idea that the higher the tissue type / same blood group ; amount of alcohol consumed, the higher the (irradiation of bone marrow) 1 mark for t o number of deaths from liver disease. stop white blood cell production; (c) 1 mark for the idea that some other factor (treated with drugs) 1 mark for suppress could be causing deaths from liver disease in immune system; Germany eg. diet . (sterile conditions) 1 mark for avoid Total 6 marks exposure to pathogens / infection. 24(a) 1 mark for each of the following ideas: Total 8 marks emphysema cases increase with an increase in the number of cigarettes smoked per day ; 1 mark for digestion / hydrolysis; tuberculosis cases are unaffected by the 1 mark for the idea that they are made into number of cigarettes smoked per day . proteins. (b) 1 mark for each of the following: 1 mark for lymphocytes (a type of white cancer; heart disease. blood cell ); Total 4 marks 1 mark for the following ideas: 25(a) (i) 1 mark for the idea that the more alcohol HIV infection; intake the greater the blood alcohol level ; damage to bone marrow (site of protection (ii) 1 mark for the idea that smaller people of lymphocytes); have a greater blood alcohol level than stress, etc.; bigger people; 1 mark each for two of the following ideas: (iii) 1 mark for the idea that females have a transplant introduces ‘foreign’ cells; greater blood alcohol level than males. immune system / T cells recognise these; (b) (i) 1 mark for each of the following: attack / destroy cells of transplanted organ / lines both labelled ; rejection. one scale covers half the grid and is linear ; axes correct with alcohol consumed per hour 1 mark for the idea that antibodies pass as independent variable and blood alcohol (through the placenta) from the mother to level as the dependent variable; the baby / via colostrum / mother’s milk . 2 marks for points plotted accurately . 1 mark for 10 weeks; (ii) 1 mark for answer in the range 6.2 to 6.6 ; 1 mark for passive; (iii) 1 mark for 125 . 1 mark for the idea that this is because the (c) 3 marks for correctly completing table with antibodies are given to the person rather cerebellum; cerebrum; and medulla than being produced within the person. oblongata. Total 10 marks Total 13 marks © Gareth Williams, 2011
Further questions on Plants as organisms ᮣ
pages 211–12
Feeding in plants 1 (a)
(b) (i) (ii) (iii)
(c) (d) (i) (ii)
1 mark for one idea eg. flat – to capture as much light energy as possible; contain chlorophyll – to capture light energy . 1 mark for each of the following ideas: to allow light to penetrate to the palisade cells; for maximum absorption of light (which comes from above); gases enter via the stomata and from here must diffuse quickly to the palisade cells where most photosynthesis occurs. 1 mark for chlorophyll . 1 mark for each of the following ideas: increase – since there will be more available light ; decrease – the higher the temperature, the faster the chemical reactions in photosynthesis. Total 7 marks
1 mark for the idea that it is to prevent light reaching that part of the leaf . (b) (i) 1 mark for iodine solution; (ii) 1 mark each for: X – blue / black; Y – yellow / straw coloured / light brown. (c) 1 mark for the idea that leaves need light to produce starch. Total 5 marks
4 (a) (i) 1 mark for each of the following ideas: increasing light intensity increases the rate of photosynthesis; until some other factor limits the rate of photosynthesis; (ii) 1 mark for carbon dioxide or temperature; (iii) 1 mark for a graph with the same shape as that in (a)(i). (b) 1 mark for respiration or converted into other substances for growth. Total 5 marks 5 (a)
(b)
2 (a)
3 (a) (i) 1 mark each for: carbon dioxide; water ; (ii) 1 mark for photosynthesis. (b) (i) 1 mark for each of the following ideas: the amount rises as it is made by photosynthesis; the amount falls as it is converted into starch for storage or into other materials for growth; (ii) 1 mark for the idea that the plants are growing so there will be more leaves producing sugars; (iii) 1 mark for the idea that it was a dull day so there was less photosynthesis. (c) 1 mark for each of the following ideas: the temperature would increase, so increasing the rate of photosynthesis; burning gas results in the production of carbon dioxide – increased amounts of carbon dioxide increase the rate of photosynthesis. Total 9 marks
(c)
(d)
6 (a)
1 mark for each of the following: a y -axis scale from 0–120 arbitrary units filling graph paper vertically and an x -axis scale from 0–1.5% carbon dioxide concentration filling graph paper horizontally ; all points correctly plotted with a line of best fit drawn. 1 mark for each of the following ideas: increasing the concentration of carbon dioxide increases the rate of photosynthesis; until some other factor limits the rate of photosynthesis. 1 mark each for: light intensity ; temperature. 1 mark for each of two of the following ideas: the temperature is naturally higher inside the greenhouse; the temperature inside can be raised artificially ; the carbon dioxide content of the air inside can be raised artificially ; controlling pests is easier . Total 8 marks
1 mark each for two of: nitrate; phosphate; potassium. (b) 1 mark for 19 tonnes. (c) 1 mark for each of the following ideas: (i) increase; (ii) decrease. (d) 1 mark for each of the following ideas: advantages: safer to eat ie. food less likely to be contaminated with toxins; less detrimental effect on environment eg. pesticides kill many organisms which are not pests or fertilisers may cause eutrophication or production of fertilisers / pesticides uses valuable energy resources. disadvantages: yields often lower ; often more expensive. Total 9 marks
© Gareth Williams, 2011
pages 213–14 7 (a) (i) (ii) (b) (i) (ii) (c)
(d)
8 (a)
Further questions on Plants as organisms
1 mark for carbon dioxide; ᮣ Plant transport 1 mark for oxygen. 9 (a) (i) 1 mark for transpiration; 1 mark for xylem; (ii) 1 mark for stomata; 1 mark for phloem. (iii) 1 mark for each of the following ideas: 1 mark for the idea that it provides energy / movement of water used to transport ; light energy converted to chemical energy . mineral salts; 1 mark each for three of the following from roots to leaves. ideas: (b) 1 mark for each of the following ideas: starch insoluble/sugars soluble or in solution; (i) increase rate at which bubble moves starch does not exert osmotic effect (or a lot towards the plant ; of sugar would tend to draw water into the (ii) decrease rate at which bubble moves cell); towards the plant ; starch ‘metabolically inert’ / does not react (iii) move bubble away from the plant . easily with other substances in the cell; (c) 1 mark for each of the following ideas: starch (insoluble) takes up less space in the reduced surface area so reduced cell. transpiration rate; Total 8 marks protection from browsing animals. Total 10 marks 1 mark for each letter, in the order of the
descriptions given in the table: C; A; E; B; D ; (b) (i) 1 mark for photosynthesis; (ii) 1 mark for one of the following ideas: different weather ie. cloudier around 6.00 p.m. for day X / sunnier on day Y; short daylight on day X / dark later on day Y. (c) 1 mark for about 3.00 p.m. / 15.00 hours. (d) 1 mark for each of two substances, such as: water; nitrate; phosphate; magnesium; calcium, etc. Total 10 marks
10(a) (b)
(c)
11(a)
(b)
(c)
© Gareth Williams, 2011
1 mark for photosynthesis. 1 mark for each of the following ideas: by osmosis; through the partially-permeable membrane of the root hair; concentration of water molecules higher in soil than in root hair cell ; water molecules move along their diffusion gradient . 1 mark for each of the following ideas: transpiration exerts a pull ; on the water in the xylem; water molecules are cohesive so the column of water is pulled up the xylem. Total 8 marks 1 mark for each of the following ideas: the tip; shading the tip results in no response; shading the area below the tip has no effect on the response; 1 mark for each of the following ideas: increased concentration of auxin / hormone on shaded side of stem ; results in increased growth of cells on shaded side; resulting in curvature towards light . 1 mark for each of the following ideas: plants grow towards maximum light ; which they need for photosynthesis. Total 8 marks
Further questions on Plants as organisms 12(a) (b) (c)
(d)
page 214
1 mark for 6.0 mm 1 mark for day 6 . 1 mark each for: 20mm; 26mm; 40mm; 60mm; 1 mark for each of the following: a y -axis scale from 0–60 mm filling graph paper vertically ; an x -axis scale from 0–8 days filling graph paper horizontally ; all points correctly plotted; line of best fit drawn . Total 10 marks
© Gareth Williams, 2011
pages 276–8 ᮣ
Further questions on Variation, inheritance and evolution
Inheritance
3 (a)
1 (a)
Two marks for a fully correct answer, one mark deducted for each mistake: C – G ; A – T ; C – G; G – C ; T – A; T – A. (b) (i) 1 mark for each of two of the following ideas: X rays; nuclear radiation; ultra-violet light ; some chemicals eg. mustard gas; (ii) 1 mark for each of the following ideas: DNA carries a particular sequence of nucleotide bases; three bases code for one amino acid ; if the sequence of bases is changed the wrong amino acid is assembled into the protein chain. Total 7 marks
2 (a) (i) 1 mark for each of the following ideas: chromosomes shorten; appear as double strands (two chromatids); nuclear membrane disappears, spindle formed ; chromosomes lie on equator of spindle; chromatids pulled to opposite poles of spindle; each set of chromatids surrounded by new nuclear membrane; (ii) 1 mark for each of the following ideas: the number of chromosomes is halved during meiosis; in mitosis it is the same ; the cells produced by meiosis do not contain identical genetic information; cells produced by mitosis are genetically identical ; (iii) 1 mark each for: testes; ovaries. (b) (i) 1 mark for each of the following ideas: a change; in genetic information; (ii) 1 mark for each of the following ideas: the condition is Down’s syndrome; the child has an extra chromosome; in the first division of meiosis ; 24 chromosomes went to one pole rather than 23; resulting in an egg with 24 chromosomes rather than 23; egg was fertilised by a sperm with 23 chromosomes resulting in a zygote with 47 chromosomes. Total 20 marks
(b)
1 mark for each correct row : Hh; H h H h; HH hh Hh; normal, sickle, normal and sickle. 1 mark for each of the following ideas: no possibility of them having children that have the sickle condition; since neither Joan nor Eric has the sickle allele. Total 6 marks
4 (a) (i) 1 mark for each of the following ideas: one extra chromosome; in pair number 21; (ii) 1 mark for each of the following ideas: the chromosomes do not divide into two equal halves; an egg with 24 chromosomes (one extra) is fertilised by a sperm with 23 . (b) (i) 1 mark for each row on the genetic diagram parents genotypes hh Hh; gamete genotypes h or h H or h ; offspring genotypes hh Hh Hh hh; offspring with hh are normal ; (ii) 1 mark for the idea that since symptoms do not appear until middle age, the person may have become a parent before symptoms appear. Total 9 marks 5 (a)
1 mark each for: (i) accidental loss of arm; (ii) blood group or gender or eye colour ; (iii) mass. (b) 1 mark for chromosome. (c) 1 mark for the idea that only one allele is required for the character to be shown in the phenotype (rather than two for a recessive allele). Total 5 marks
6
1 mark for correct genotypes of parents and gametes: Aa and Aa, A or a and A or a. 1 mark for genotypes of offspring: AA Aa Aa aa. 1 mark for phenotypes of offspring: 3 normal : 1 albino . Total 3 marks
7 (a)
1 mark for each of the following: A ϭ Dd; B ϭ dd; If A were DD then there would be no non- affected offspring, so A must be Dd . 1 mark for each of the following ideas: If the disease was caused by a recessive allele then: A could have two recessive alleles (dd); B could be a carrier (Dd). Total 5 marks
(b)
© Gareth Williams, 2011
Further questions on Variation, inheritance and evolution
pages 278–80
8 (a) (i) 1 mark for from the udder ; ᮣ Evolution (ii) 1 mark for the idea to make sure that the 10(a) 1 mark for a suggestion related to food new cell contained only new DNA (ie. not shortages or fear of prison eg. there were from the original cell) / zygote must be food shortages so they wanted to believe diploid to develop (so cannot have three him. sets of chromosomes); (b) 1 mark for DNA / genes are not changed ; (iii) 1 mark for sheep A. 1 mark for environmental changes are not (b) 1 mark for the idea that the egg is normally inherited . fertilised by a sperm from the male sheep / (c) 1 mark for choose plants with the largest ram. fruit ; (c) 1 mark each for the following ideas: 1 mark for breed ; that people understand the work of 1 mark for select largest offspring ; scientists; 1 mark for repeat over several generations. people can then see if the advances in (maximum of 3 marks if ideas are not well science are important in their own work / expressed) occupation. Total 7 marks (d) 1 mark for the idea that people can get animals with desirable chacteristics (more 11(a) 1 mark for genes are on the chromosomes; quickly than with conventional breeding). 1 mark for chromosomes / genes are copied Total 8 marks (before cell division). (b) 1 mark each for any three of the following 9 (a) 1 mark for idea that it is one that can be ideas: inherited / passed on through the genes / is interferes with nature / lack of choice; due to a gene mutation. unknown side effects on humans; (b) 1 mark for idea that passage for air to (and further selective breeding is more difficult ; from) the lungs / bronchioles is blocked or reduced number of alleles in population / restricted / air cannot reach air sacs / they are all genetically identical . prevents gas exchange / prevents removal of Total 5 marks carbon dioxide.
(c) (d) (i) (ii) (iii) (iv) (e)
1 mark for the idea that bacteria are killed / destroyed / growth (of bacteria) is inhibited . 1 mark for each of the following: Nn; Nn; nn; NN or Nn. (2 marks) 1 mark for one correct answer. (Note: There are many possible answers and these cannot all be listed here.) The likely answers depend on what is given in the syllabus / specification, eg. Huntington’s chorea / disease; haemophilia; sickle cell disease; muscular dystrophy, etc. Total 9 marks
12
13(a)
1 mark for each correct word used in the following order: gene; restriction; plasmid; ligase; DNA; fermenter; diabetes. Total 7 marks
1 mark for each of the following ideas: quicker; cheaper; no allergic reaction (b) (i) 1 mark for EDBAC; (ii) 1 mark for each of the following ideas: bacteria multiply; gene is copied into each bacteria; lots of insulin produced . (c) 1 mark for each of the following ideas: against God or nature; unknown consequences. Total 9 marks
© Gareth Williams, 2011
pages 280–81
Further questions on Variation, inheritance and evolution
14(a) (i) 1 mark for each of two of the following ideas: they control characteristics; they are passed on from parents; they are part of chromosomes or DNA; (ii) 1 mark for each of two of the following ideas: they have eaten more food than the others; they are pregnant females; they have low metabolic rates. (b) 2 marks for each of 3 matching pairs of ideas: grey squirrels can out-compete red squirrels for food ; so will not starve or can reproduce more successfully ; grey squirrels can live in a greater variety of woodlands; so have a greater chance of surviving if one type of habitat is destroyed ; grey squirrels have a higher reproductive rate than reds; so their population will rise faster . Total 10 marks 15(a) 1 mark for (i) – B and (ii) – A and (iii) – C . (b) (i) 1 mark for natural selection; (ii) 1 mark for each of the following ideas: mutation produced some birds with thinner beaks; competition for small insects as food ; birds with thinner beaks could eat smaller insects therefore survive to breed . Total 5 marks 16(a) (i) 1 mark for countryside; (ii) 1 mark for each of the following ideas: light coloured moth increased in numbers because less soot was deposited on trees; therefore the moths were less conspicuous to birds; dark coloured moths decreased in numbers; because they became more conspicuous to birds; (iii) 1 mark for natural selection. (b) 1 mark for each correct total and mean 41 and 8.2 ; 13 and 2.6 ; 16 and 3.2 ; 36 and 7.2 . (c) 1 mark for city trees. Total 11 marks
© Gareth Williams, 2011
Further questions on Living things and their environment ᮣ
Adaptation and competition 1 (a)
(b)
2 (a)
(b)
(c) (d)
3 (a)
(i) (ii) (iii) (b)
(c) (i) (ii)
1 mark each for two differences eg.: trees in wood taller ; trees in wood are narrower ; trees in wood have fewer leaves / branches higher up. 1 mark each for: light ; water ; mineral salts. Total 5 marks 1 mark for each of the following ideas: either fat is an energy store; animal can go a long time without food ; or fat can be broken down into water ; not much available water in desert . no sweating reduces water loss; can go longer without drinking / not much water in desert . weight spread out over large area; less likely to sink into sand . acts as an insulator ; so that they stay warm at night . Total 8 marks
pages 340–41
5 (a) (i) 1 mark for 10 years; (ii) 1 mark for 1986 . (b) (i) 1 mark for the idea that the lynx population is also increasing ; (ii) 1 mark for the idea that there were more prey (hares) for the lynx to feed on. (c) 1 mark each for three of the following ideas: high number of lynxes feeding on the hares; another predator feeding on the hares; lack of food for hares (for other reasons); lack of space; disease (in the hare population); adverse conditions (eg. weather) affecting hare populations; human interference (eg. hunting or capture). (d) 1 mark for increase. (e) (i) 1 mark for idea that this would reduce it ; (ii) 1 mark for the idea that this is because there are fewer hares / less food to feed on / more competition from foxes for food . Total 10 marks
1 mark each for: day 2 ; day 4; day 3 . 1 mark each for: food availability ; oxygen availability ; amount of poisonous waste products. 1 mark for all dead ; 1 mark for the idea that the food supply is exhausted . Total 8 marks
4 (a)
1 mark for each of the following: fleshy stem; thick waxy cuticle . (b) (i) 1 mark for transpiration; (ii) 1 mark for the idea that it is cooler / more humid at night, so less water is lost by transpiration. (c) 1 mark for the idea that leaves are reduced to spines, so the stem takes over the role of photosynthesis. (d) 1 mark for the idea that in the hottest part of the day / there will be few insects around for pollination. Total 6 marks
© Gareth Williams, 2011
pages 341–3 ᮣ
Further questions on Living things and their environment
Energy and nutrient transfer
10 (a)
6 (a) (i) 1 mark for any one of frog, heron, stickleback, perch, water beetle, pike ; (ii) 1 mark for four . (b) (i) 1 mark for the idea that they would increase because the pike are no longer eating them; (ii) 1 mark for each of the following ideas: decrease because herons would eat more of them; because there would be fewer pike for the herons to feed on. (c) 1 mark for each of the following ideas: decrease numbers of primary consumers; because carp would compete with them for food ; decrease numbers of secondary consumers; because they would have fewer primary consumers to feed on. Total 9 marks 7 (a)
1 mark each for: heather and grass at base of food web; arrows from heather and grass to grouse; and to voles; arrows from grouse to foxes; and from voles to foxes. (b) 1 mark for shelter or nesting sites. (c) (i) 1 mark for decrease; (ii) 1 mark for more vegetation since less grouse to eat it . Total 8 marks
8 (a) (i) 1 mark for C ; (ii) 1 mark for the idea that it is the mass of all the organisms; (iii) 1 mark each for: pyramid with oak, caterpillar, vole and owl in ascending order ; layers – widest is oak followed by caterpillar, vole, and owl in decreasing widths; (iv) 1 mark for the idea that it is lost as heat from respiration. (b) 1 mark for each of the following ideas: pollution eg. increased sulfur dioxide ; could kill off some of the lichens or cause leaf fall in trees. Total 7 marks 9 (a) (i) 1 mark for photosynthesis; (ii) 1 mark for the change of light energy to chemical energy . (b) (i) 1 mark for respiration; (ii) 1 mark for heat / thermal (energy ); (iii) 1 mark for 60%. Total 5 marks
(b) (i)
(ii)
(iii)
(c) (i) (ii)
1 mark each for: artificial fertilisers intensive; not using herbicides organic; having a compost heap organic; crop rotation organic; having very large fields intensive; keeping hedgerows organic; weeding by hand organic. 1 mark for each of the following ideas: produce more food ; from same amount of land; 1 mark for good example eg. fish farming or greenhouse or hydrophonics or battery chickens. 1 mark for a good explanation eg. avoids the need to go out and catch the fish . 1 mark for idea of production costs are higher . 1 mark for good explanation eg. more manual labour . 1 mark for idea of less pests eating the food . 1 mark for idea of less steps in food chain so less energy lost . Total 15 marks
11(a) (i) 1 mark for photosynthesis; (ii) 1 mark for respiration. (b) (i) 1 mark for each stage of the calculation: (Note: Tertiary consumer ϭ level D and secondary consumer ϭ level C) tertiary consumers receive a total of 120 units of energy from secondary consumers and lose 24 units of energy to decomposers; so energy transferred to environment is (120 Ϫ 24) ϭ 96, therefore % energy transferred ϭ (96 ϫ 100) Ϭ 120 ϭ 80%. (ii) 1 mark for two of the following ideas: (mammals and birds are) more active so more respiration generating heat; (mammals and birds have) constant body temperature; (mammals and birds) lose heat faster to the environment, so faster rate of respiration to replace it. Total 6 marks 12 (a)
(b)
(c)
© Gareth Williams, 2011
1 mark for 12 Ϭ 80 ϫ 100 ; 1 mark for 15. 1 mark for each of two of the following: biomass lost in faeces / waste; biomass used in respiration; biomass used in growth / repair . 1 mark for less biomass used in respiration ; 1 mark for as less movement ; 1 mark for less energy needed to maintain body temperature. Total 7 marks
Further questions on Living things and their environment 13(a)
1 mark each for: X – photosynthesis; Y – respiration. (b) 1 mark for feeding / eaten. (c) 1 mark each for: (i) when it is burned; (ii) greenhouse effect / global warming; (iii) decay . Total 6 marks
ᮣ
15(a)
(b)
(c)
Humans and the environment 14(a)
1 mark for each of three of the following ideas: to produce more farmland ; new towns; roads; for fuel ; to export timber. (b) (i) 1 mark for increasing ; (ii) 1 mark for each of the following ideas: less trees to remove carbon dioxide during photosynthesis; combustion of trees releases carbon dioxide. (iii) 1 mark for each of the following ideas: increase in carbon dioxide may add to greenhouse effect ; resulting in global warming ; less transpiration may lead to drier climates ; increased leaching of mineral salts from soil; increased soil erosion since fewer tree roots to bind soil. (c) 1 mark for each of two of the following ideas: set-aside provides wider range of habitats / food plants / breeding sites; sites of special scientific interest / nature reserves – havens for threatened species; captive breeding programmes – release into wild ; reduce use of herbicides – rare species less likely to be killed; reduce use of insecticides – effect on food chains; reduce use of fertilisers – reference to eutrophication effects; conserve hedgerows, provides wide range of habitats / food plants / breeding sites. Total 13 marks
pages 344–5 1 mark each for two of the following ideas: the ash contains nutrients; eg. nitrate/phosphate, etc.; acts as a fertiliser / improves plant growth. 1 mark for each of the following ideas: cattle produce methane; in digestive system / stomach. 1 mark each for two of the following ideas: during growth, trees take in nitrate / increase because nitrate no longer taken up; increased leaching / washing out of nitrate from the soil (and so into stream); decomposition of trees or other material left after cutting down forest (releases nitrate). Total 6 marks
16(a) (i) 1 mark for idea of protecting fish stocks; (ii) 1 mark for each of the following ideas: for meat; for cosmetics; (iii) 1 mark for each of the following: argument for; argument against ; choice made. (b) (i) 1 mark for idea that a natural resource is maintained ; (ii) 1 mark for idea of fishing quotas or ban fishing . Total 8 marks 17(a) (i) 1 mark for each of the following: carbon dioxide equals 0.037; water vapour equals 0.1; (ii) 1 mark for each of the following ideas: both effect factor and volume influence greenhouse effect; water vapour has the greatest greenhouse effect . (b) 1 mark for each of the following ideas: at stage 1 radiation reaches the Earth and some is reflected and some is used in photosynthesis; at stage 2 radiation escapes but some is trapped . (c) 1 mark for each of the following ideas (max. of two): global warming; leading to ice caps melting; leading to a rise in sea level; causing changes in populations of living organisms. (d) 1 mark for each of the following ideas: ultra-violet light enters; and can cause skin cancer . Total 10 marks
© Gareth Williams, 2011
page 345 18(a)
(b)
(c)
Further questions on Living things and their environment
1 mark for (for crops) to make protein. 1 mark for growth / increase yield . 1 mark each for any six of the following: rapid / more growth of (water) plants; increased competition for light / no light to plants below; death of plants / algae; food for microbes / dead plants decayed by microbes; microbes increase in number; oxygen used (by microbes); in respiration (of microbes); lack of oxygen kills fish / fish suffocate . 1 mark for correct use of at least two scientific terms, eg . nitrifying, putrefying, ammonium compounds, ammonia, nitrite, denitrifying . 1 mark each for any three from: protein is turned to ammonia; (protein broken down by) putrefying bacteria or putrefying bacteria (produce ammonia); ammonia is turned to nitrate; (ammonia is used by) nitrifying bacteria or nitrifying bacteria (produce nitrate). Total 12 marks
© Gareth Williams, 2011
Further questions on Biotechnology and Behaviour ᮣ
Biotechnology
4 (a)
1 (a) (i) 1 mark for idea of heating to high temperature/boil for a short time. (ii) 1 mark for idea that this kills (other) microbes/micro-organisms in the milk (not wanted for yoghurt-making process). (b) 1 mark each for two of the following ideas: (the bacteria) ferment/convert lactose in the milk to lactic acid; more acid gives lower pH; (low pH) causes protein to coagulate/clot (makes yoghurt thicker). (c) 1 mark each for the following ideas: good/optimum/suitable temperature for enzyme activity; fermentation proceeds more quickly. (d) 1 mark each for the following ideas: reduces/slows down further bacterial activity/fermentation; (further activity) might change flavour/alter texture etc. of yoghurt. Total 8 marks 2 (a) (b)
(c)
(d)
pages 371
(b) (c)
1 mark for stirring / mixing contents. 1 mark for one of the following: nutrient(s) (solution) / named nutrient; microbes (culture) / micro-organisms. 1 mark for each of the following ideas: heat given off (in respiration of microbes / micro-organisms); high temperatures harmful to microbes / micro-organisms / enzymes (in cell reactions). provide oxygen (for respiration). Total 5 marks
3 (a) (i) Plot graph with time on horizontal axis and pH on vertical axis (given in question) – so find suitable scale using most of graph paper and make sure each point is plotted accurately and line drawn to connect points. (ii) 1 mark for a pH of 5.4 (or as read off from the plotted graph). (b) (i) 1 mark for each of the following ideas: bacteria / Lactobacillus / Streptococcus ferment lactose / milk sugar; to lactic acid; so culture / milk becomes more acid / pH falls. (ii) 1 mark for idea that acid / lower pH causes proteins / casein to coagulate / clot / curdle. (c) 1 mark each for the following ideas: suitable / optimum temperature; for enzyme action (in these microbes / bacteria). Total 10 marks
© Gareth Williams, 2011
1 mark each for two of the following ideas: waste plant / vegetable matter (eg. household / garden / agricultural wastes, etc.); waste animal matter (eg. faeces / dung / manure etc.). 1 mark for methane. 1 mark for each of the following ideas: keeps air out; keeps inside anaerobic; stronger container (withstands pressure of gas building up inside). Total 6 marks
