Biology For You Intro and Answers to Further Questions

© Gareth Williams, 2011

Gareth WilliamsWith the support of: Keith Johnson, Lawrie Ryan, Bob Wakefield, Phil Bunyan,

Keith Hirst, Erica Clark, Roger Frost, Nick Paul, Paul Connell,Byron Dawson, Niva Miles, David Barrett, Janet Hawkins, John Bailey,

Rosie Davison, Tom Spicer, Adrian Wheaton, Diana Williams.


Students’ ChecklistsStudents learn best when they are clear about whatthey should know and understand.To help your students, we provide a photocopiableChecklist for each topic.Each Checklist has sections on ‘What I should know’and ‘What I should be able to do’. On the CD HigherTier concepts are marked .

A Checklist has 3 possible uses:• To give to your students at the start of the topic,so they can use it for self-assessment andtick off each item as they understand it.Students will be able to tick off items for each lesson.This can be very motivating and encouraging.

• To be used by the students as a summary, to helptheir revision for the internal and GCSE examinations.

• To use as part of a Record of Achievement, whichalso informs parents of their child’s progress.

By collecting the Checklists (and Revision Quizzes)your students can build up their own Revision Book.

What I should know:

o Enzymes are biological catalysts thatincrease the rate of a reaction.

o Enzymes work on substances calledsubstrates.

o Some enzymes can break down largemolecules, others can build them up.

o All enzymes are proteins.

o Each enzyme controls one particularreaction.

o Enzymes can be used again and again.

o Each enzyme has an optimumtemperature and is denatured by boiling.

o Most enzymes have an optimum pH andare affected by changes in acidic oralkaline conditions.

o Carbohydrases break down carbohydrates.Proteases break down proteins.Lipases break down fats.

o Immobilised enzymes are ‘fixed’ to smallresin beads. They enable the enzyme to beused again and again.

o

Name Class

While studying this topic, tick off each item after you have covered it.

3333 Enzymes

What I should be able to do:

o Draw diagrams to explain how the activesite enables an enzyme to work.

o Carry out an experiment to show howcatalase breaks down hydrogen peroxide.

o Carry out an experiment to see howquickly amylase can break down starch.

o Follow the course of an enzyme-controlledreaction as shown by a graph.

o Plan an investigation into the effect oftemperature on the action of an enzyme.

o Carry out an experiment to see the effectof pH on the action of a protease.

o Interpret a graph showing the effect of pHon enzyme action.

o Carry out an experiment to show howstarch molecules can be built up fromglucose molecules.

o Use immobilised yeast enzyme to breakdown sucrose to simple sugars.

o Plan an investigation into the action ofbiological washing powders.

o Use pectinase enzyme to extract juice fromapple.

Checklist3

�H


Revision Quiz

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 bycovering up the right-hand side of the sheet, but in any caseit provides them with an accurate summary of knowledgeeven if they have imperfect notes in their exercise books.

Use these questions to help you revise (cover the right-hand side with a sheet of paper).

1 What do plants need to carry outphotosynthesis? (page 181)

2 What is the word equation forphotosynthesis? (p. 181)

3 What is a variegated leaf? (p. 183)

4 How could you prove that carbon dioxide isneeded for photosynthesis? (p. 184)

5 What can the sugar made in photosynthesisbe used for? (p. 185)

6 What other substances can sugar beconverted to in a plant? (p. 185)

7 Give 3 ways in which plants are important tohumans. (p. 186)

8 How might the rate of photosynthesis of aplant be limited? (pp. 187–9)

9 What are limiting factors? (p. 188)

10 How are leaves adapted to absorb sunlight?(p. 190)

11 How are leaves adapted for gas exchange?(pp. 190–91)

12 When do photosynthesis and respirationtake place in a plant? (p. 192)

13 What are fertilisers? (p. 194)

14 What is the hormone produced by the shoottip that stimulates the shoot to grow?(p. 197)

15 What does it mean if a shoot is positivelyphototropic? (p. 197)

... chlorophyll, carbon dioxide, water andsunlight.

... carbon light anddioxide + water chlorophyll glucose + oxygen

... a leaf with some parts white wherechlorophyll is missing.

... enclose a destarched plant in a plastic bagwith soda lime. Leave the plant in sunlightfor a few hours. Test a leaf for starch.

... some is used in respiration, some ischanged to starch and stored, some isused to make cellulose.

... amino acids (which are built up intoproteins), fats and oils.

... as food, as medicines, to keep the level of carbon dioxide and oxygen in theatmosphere stable, building materials, andfuels. (3 needed)

... low temperature, shortage of carbondioxide or shortage of light.

... factors like light intensity, that can affectthe rate of photosynthesis.

... they have a large surface area and lots ofchloroplasts in the palisade layer.

... they are thin and allow gases to diffuse inand out through holes called stomata.

... photosynthesis takes place in the light.Respiration takes place all the time.

... chemicals that are added to the soil toreplace missing nutrients removed by acrop.

... auxin.

... the shoot grows towards light.

11112222 Feeding in plants RevisionQUIZ


● Further Content SheetsThese sheets are used to take a topicfurther. For example, ‘Black panthersand leopards’ is a more demandinggenetics cross and ‘Caterpillars’conquest’ gives an in-depth example ofbiological control.

Many of the Further Content Sheetsinclude comprehension exercises andprovide a useful homework resource.

● Changing Ideas SheetsThese extension sheets (marked with a

in the topic Maps) require the studentsto research an idea (in Biology for You orelsewhere, perhaps the Internet).Developing comprehension skills andother aspects of literacy, these sheetsare useful as a homework resource.

There is a summary of all Help andExtension Sheets on the next six pages.

hormone gland which secretes it when secreted other points

growth hormone pituitary

when glucose level risesin the blood

adrenaline prepares body for ‘fight or flight’

thyroid

controlssex hormones development of

sex organs

Label the diagram with the name of the hormonal glands using the words in this list :testes thyroid pancreas pituitary ovaries adrenals

Hormonespages120–122

HelpSheet

Help Sheets and Extension SheetsThese sheets are also photocopiable, and include:

● Content Help SheetsWhere a diagram in Biology for You may be too complicated ortoo time-consuming for your students to draw, we provide aphotocopiable version (at a size suitable for sticking intoexercise books).

Some of the diagrams are two-dimensional versions thatregularly come up in examination papers, e.g. a section of a leafand the human digestive system. Students are often asked tolabel these and extra questions are provided to focus theirminds on the diagram. The students’ understanding of thediagram will often be improved if you tell them to colour the keyparts (based on colours in Biology for You).

Most of the diagrams from the Pupils’ Book are provided for youto use with a data-projector.

Some other Content Help Sheets may introduce a different slanton some of the work covered in the students’ book. Thisencourages them to apply their knowledge to a new situation.

You may find many of the Content Help Sheets useful forhomework or for work when staff are absent.

● OHP SheetsThere are a number of sheets for making overhead projectortransparencies. In addition, many of the Content Help Sheets aresuitable (enlarged) to make OHP transparencies to support andfacilitate your teaching.If you have a data-projector, these OHP sheets are extended bythe Power Point presentations also provided.

● Investigation Help SheetsA number of Investigation Help Sheets are provided, from whichyou can select the investigations that you want your students totackle. The format of these sheets is based on the one used verysuccessfully in the Spotlight Science scheme for Key Stage 3.You have the choice of providing your students with just theopening description of the task or the full sheet with its ‘Thinkabout ...’ section of hints and tips.

● Step-by-step Experiment SheetsWhere an experiment described in Biology for You may needfurther support, we provide a Help Sheet to give the studentmore guidance. A visual impression is given of each stage in theexperiment. This step-by-step approach is presented as a ‘flow-diagram’ of the experiment. Students often find it easier to followan illustration than a set of instructions. Many of these Step-by-step Experiment Sheets include a table that students can copyand fill in with their results. Some questions are included at thebottom of the sheet to re-inforce points from the experiment.


“Teacher-Map” outline of the chapterFor each chapter in the pupils’ book we provide a topic outline,which gives you an overview of the work covered, and shows youthe sequence of concepts on a Topic Map; this gives you a quickvisual summary of each topic.

Icons on the Map indicate:

Opportunities for using ICT (see “Using computers and ICT withBiology for You”)

Opportunities to discuss how scientific ideas have changed overtime (see “How Science Works: Changing ideas”

Opportunities for developing Key Skills (see “Key SkillsOpportunities”)

You can produce a very useful staff booklet by:

• Editing these sheets against your particularexamination syllabus, and putting a line throughunwanted sections. You will find it very helpful tovisit www.biologyforyou.co.uk

• Using highlighter pens to colour-code key items (e.g.essential experiments, optional experiments, work tobe attempted only with more-able groups, etc.)

• Adding an indication of timing (e.g. a marker of wherethe class should be by half-term, Christmas, etc.)

• Stapling the sheets into a booklet as a useful workingdocument or visual Scheme of Work.

Ticks (plus dates?) can be used to keep a record of progress.

New Biology for You Nelson Thornes Ltd. 149 © Gareth Williams

Controlling conditionsDefinition of homeostasisNature of feedback■ OHP SheetOutline of control systems

Controlling blood sugarRole of insulin and glucagon■ OHP SheetDiabetes■ Further Content Sheet

Controlling body waterOsmoregulation by kidneyControl by ADH■ OHP SheetKidney dialysis machineKidney transplants■ OHP Sheet, Further Content Sheet

Controlling body temperatureWarm-blooded and cold-bloodedSkin structure■ Content SheetReaction of skin to overheating and overcooling■ OHP Sheet, Content SheetHypothermia

Excretion and the kidneysNature of excretion and deaminationUrinary system■ OHP Sheet, Content SheetInside the kidneys ■ Content SheetNephron structure and function■ Content Sheet, 2 OHP Sheets

Map

Codes used on the Maps:

n Help Sheet or Extension Sheet available

Opportunity for using a resource on the CD

Opportunity for using ICT (see page 00)

Opportunity to discuss how scientific ideashave changed over time (see page 00)

Opportunity to develop Key Skills (page 00)


Homeostasis means keeping conditions insidethe body constant.

Conditions include temperature, blood sugar,water, pH and carbon dioxide.

Homeostasis uses feedback.

Insulin lowers blood sugar by changing glucoseto glycogen.

Glucagon raises blood sugar by changingglycogen 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 thebody.

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.

“Student-Map” for each chapterThe Topic Map is also provided in very large type, so you canmake an OHP transparency from it or use it directly on your data-projector. It can also be enlarged to make a wall poster.

We believe students’ learning is enhanced if you can make it lessof a ‘magical mystery tour’, by using the Map:

• at the start of the lesson, to remind them of what theydid in previous lessons in this topic, and to give theman outline of today’s ‘territory’,

• at the end of the lesson to summarise and remindthem of what they have experienced and learnedtoday, 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 ofpaper (so that you can read it, but the class cannot) and thenphrasing a question to the class based on each OHP statement.For example, on the third OHP sheet, you could ask ‘What affectsthe action of an enzyme?’ and then when the class respond (orwrite down their answer) you can reveal the relevant lines to giveinstant and effective positive feedback and reinforcement.You could use this method for a quick test at the end of eachchapter.

Map


Chapter Students’ Title of sheet Content Use for Investigation Step-by- Furtherpage Help OHP Help Sheet step content

Sheet ExperimentSheet

1 8 Using the microscope �8 Parts of the microscope � �9 Looking at plant cells �9 Looking at animal cells �10 Specialised cells �14 How to get the most dye out of �

beetroot cells

2 17 The rate of diffusion �18 A model cell �18 Osmosis � �19 Osmosis in potato cells �20 The effects of sugar solutions �

on potato cells

3 29 The effect of amylase on starch �30 What effect does temperature �

have on the action of anenzyme?

31 The effect of pH on the action of �a protease

31 The action of protease on protein �32 Building starch from glucose �33 Changing sucrose into simple �

sugars34 Comparing the action of �

biological and non-biologicalwashing powder

34 To find out the effect of �temperature on biologicalwashing powder

4 43–5 Food tests �43 Ideas about proteins �46 Measuring the energy in a peanut ��47 Recommended daily amounts �

of nutrients50 Starvation �51 Estimating vitamin C �51 Ideas about vitamins �54 Digestion of 3 types of food �

molecules by enzymes54 Assimilation � �55 Inside a tooth � �55 Fluoride fights tooth decay �55 Teeth �55 Tooth decay �56 What affects how quickly rennin �

clots milk?57 The action of lipase on milk fat �57 Your digestive system �57 Human digestive system �58 Making a model gut �

BBBB Help and Extension Sheets


5 63 Measuring the heat energy from �germinating seeds

65 Composition of inhaled and �exhaled air

68 Your breathing system �66 Respirometers �68 Your breathing system �69 Breathing in/Breathing out �69 Breathing movements �70 Respiratory surfaces �70 Gas exchange at the alveolus �71 The depth of breathing �72 Artificial respiration �72 What effect does exercise have ��

on breathing rate?73 What increases the rate of �

respiration?73 Fermentation �73 What makes dough rise faster? �

6 79 Circulation of blood through �veins, arteries and capillaries

80 A double circulation �80 Circulation of blood through �

heart and body80 Ideas about blood circulation �81 Blood vessels �81 What effect does exercise have �

on pulse rate?81 Presenting results and looking for �

patterns82 Your heart �82 Section through the heart �

85–86 Stents and ECGs �87–90 Blood cells �91 Lymph and lymphatic system � �

7 97–8 Control of body temperature/ �Control of blood sugar

98–9 Control of blood sugar level �100 Your skin �101 How the skin reduces heat loss/ �

How the skin loses heat101 How skin reacts to overheating �

and overcooling102 Your kidneys �102 The excretory system �103 Inside the kidney/How do �

nephrons work?103 Structure of a nephron �103 How a nephron filters �104 ADH control of body water �






7 105 A kidney dialysis machine �(cont.) 105 The kidney dialysis machine �

8 110 Neurones �113 A reflex arc �113 A reflex arc �114 Testing your reflexes �114 Measuring your reaction time ��114 A reaction timer �117 Inside the eye �117 Inside the eye �

120–22 Hormones �120 Chemicals in cows �123 The menstrual cycle �124 The menstrual cycle �124 Control of the menstrual cycle �

9 132 The human skeleton �132 The human skeleton (with labels) �132 The vertebral column � �133 Joints in the body �

10 139 Louis Pasteur �139 Robert Koch �

139, etc. Diseases �142 An infectious disease �142–6 Barriers to pathogens �144 Spread of disease: the dirty shop �147–9 Immunity and vaccines �149 The spread of disease �150 The discovery and development �

of penicillin154 Sexually transmitted diseases �

11 161–3 Effects of drugs and solvents �161–3 Effects of drugs and solvents ��

(answers)162 Heroin �164–5 The effects of alcohol on the �

body164 Alcohol in the blood �

12 182 Testing a leaf for starch �184–5 Factors affecting photosynthesis �184 To find out if light is need for �

photosynthesis184 Testing leaves for starch �185 Collecting oxygen gas during �

photosynthesis185 Oxygen production during �




12 photosynthesis(cont.) 188 What effect does temperature �

have on the rate ofphotosynthesis?

187–9 Factors affecting the rate of �photosynthesis

189 Photosynthesis and carbon �dioxide

189 What effect does carbon dioxide �have on the rate ofphotosynthesis?

190 Inside a leaf �190 Section of a leaf �

190, 192 Leaf structure �192 Photosynthesis and respiration �196 The grass house �

183, etc. Crop production �197–8 Phototropism in a �

shoot/Geotropism in a root

13 203 3-D diagrams of a root and a stem �204 A potato osmometer �203 Absorption by roots �204 Up the stem �205 To show transpiration takes place �205 Transpiration and the effect of �

the wind206 Effect of temperature, humidity �

and wind on rate of transpiration206 Factors affecting the rate of �

transpiration207 The potometer �207 What affects the rate of �

transpiration?

14 216 The male reproductive system � �216 The female reproductive system � �216 Fertilisation and implantation � �

216–17 How animals reproduce �217 Male and female gametes and �

Sexual intercourse217 Pregnancy � �217 Ante-natal care and birth � �217 Methods of birth control � �217 More birth control methods � �217 The placenta � �

217, 235 Fertilisation and seed formation � �218 Cloning in plants �218 Cauliflower cloning �219 Dolly the first cloned sheep �

220, 259 Designer babies �

15 225 A leaf key �




15 225 An arthropod key �(cont.) 225 A parasite key �

225 Making a key �225 A key to identify animals �226 The animal kingdom �227 The plant kingdom/The other �

three kingdoms235 Flowering plants � �235 Flower structure � �235 Pollination 1 � �235 Pollination 2 � �235 Fruits and seeds �235 Germination �235 Different pollen � �235 Pollination �235 The late-flowering magnolia �235 To see what affects the way seeds �

fall

16 240–41 A design for life �241 Building a DNA strand �241 A DNA model �243–4 The structure of DNA �243 Rosalind Franklin �244 Stages in mitosis �245 Stages in meiosis �246 Inheritance of sex �246 Sex linkage � �250 Inheritance of eye colour �251 A genetic cross �251–2 Black panthers and leopards �251–2 Punnet squares �251–2 A monohybrid cross in the �

fruit fly251–2 Codominance � �254 Haemophilia � �254–5 Genetic diseases �254–5 The inheritance of cystic fibrosis �

and Huntington’s disease258 Selective breeding �

240, etc. Genetics and society �261 For GM Foods �261 Against GM Foods �

17 266–9 Jean Baptiste Lamarck �266–9 Charles Darwin �266–9 Alfred Russel Wallace �266–7 How do species change over time? �266–7 Species and speciation � �269 The peppered moth �




17 269 The brown-lipped snail �(cont.) 270–71 Fossils �

18 283 Environmental factors in a wood �286 The growth of a yeast population �288 Using a quadrat �288 What affects the size of a �

duckweed population?288 Sampling techniques � � �289 Sampling animal populations �289 Collecting invertebrates � � �282–8 Charles Elton �293 Adaptations of plants to different �

environments298 Predators and prey �298 Predator–prey cycle �288 Looking at samples sizes – �

fieldwork289 Identifying invertebrates in leaf �

litter289 Identifying invertebrates in �

grassland and in bushes289 Identifying invertebrates in �

grassland and in bushes289 Identifying freshwater �

invertebrates288 Identifying weeds on playing fields �

19 303–4 Food chains and food webs �308–10 Energy flow through a food �

chain309–10 Energy flow through an �

ecosystem309–10 Energy flow through a �

meadow311 The water cycle � �313 The carbon cycle �313 The carbon cycle �314 The nitrogen cycle �314 The nitrogen cycle �

20 320 World food supply �324–5, 336 Different types of pollution �

326 Poison algae �326–7 Rachel Carson �327 Caterpillar’s conquest �328 Sewage treatment 1 �328 Sewage treatment 2 � �328 Sewage pollution �328 The effects of sewage pollution �

on a river.




20 329 Against rainforest clearance �(cont.) 330 For rainforest clearance �

186, etc. Conservation �336 For and against the use of �

fertilisers

21 348 Growing bacteria on an agar plate �350 Sour milk �353 An industrial fermenter �358 Mycoprotein production �

22 361 What conditions do woodlice �prefer?

361 Sample sizes in biological work �361 How do blowfly larvae respond to �

light?


Technician CardsAs an aid to technicians as well as teaching staff, we provide acomplete set of Technician cards, one for each experiment inBiology for You. See pages 373–404.They include essential Health and Safety Advice and CLEAPSSreference 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 Contentspages.

New Biology for You Nelson Thornes Ltd © Gareth Williams

Experiment 5.1 page 63Measuring the heat energy from germinating seeds(Worksheet, page 119)

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 andcooled.(You can surface sterilise seeds in 1.0% sodium chlorate(I) (hypochlorite) for 10 minutes thenrinse 3 times in clean water.)

Biology for You Technician Card

Safety, refs: CLEAPSS 1538, 1550, Hazcard 89,

Recipe card 62

Notes: Seeds sold for planting purposes will probablybe coated in a pesticide. Use peas or mung beans soldfor food purposes if at all possible. Otherwise washhands carefully with soap and water after handlingseeds for planting. The seeds should be surfacesterilised in 1.0% sodium chlorate(I) (hypochlorite) for10 minutes and then rinsed 3 times in clean water. Thisshould prevent unwanted fungal growth during theexperiment. Remember the disinfectant is corrosive atthis concentration. Wear eye protection.

Visual aids available:

Information and Communication TechnologyThere are many opportunities in Biology to support yourteaching with ICT, and we include a section giving suggestions forusing ICT with Biology for You. See pages 18–26. A list of ICTresources and contacts is given on page 27.The Map for each chapter shows these opportunities by a icon.

Answers to Further QuestionsBiology for You includes over 200 questions.In the Support Pack we provide detailed answers to all theGCSE questions. These answers, with a mark scheme, are writtenby a Chief Examiner, and are available for you to photocopy tohelp your students gain a clearer understanding of what theexaminers expect.

Examination Questions and Model AnswersWe also provide some photocopiable GCSE questions, each setout as on an examination paper, with a photocopiable MarkScheme and ‘model’ answers. See pages 49–67.These questions are chosen for their wide-ranging cross-topiccontent, and are particularly useful in the revision period beforethe final examination – if used earlier, they may appear toodaunting.

Website SupportMuch the easiest way to see which pages in Biology for You areneeded for your particular specification is to download therelevant pdf file of page references for your chosen ExaminationBoard, from: www.biologyforyou.co.uk

Photocopying and distributing this document to your pupils forthe revision period should help to focus their minds on the taskof preparing adequately for their examination.


This Examination Question covered work on:• efficiency of energy transfer (p. 310) • intensive food production (p. 316)• transgenic animals (p. 257)

Answer2

Answers Marks Notes and Hints

(a) 1 mark for 4%

(b) It becomes the energy source fordecomposers

1

1

It is a good idea to bring a calculator into theexamination with you to give you confidence withcalculation questions. Sometimes you are asked toshow your working which is worth doing becausemarks are available for working even if you get thewrong answer. However, this is not asked for inthis question. The percentage symbol is needed inthe answer so don’t forget units when you answerthis type of question.

‘Suggest’ questions are asked when the examinersfeel that you ought to be able to work out theanswer using your knowledge and understandingof the underlying principles of the informationgiven. They are similar in demand to ‘explain’questions, but they differ in that it is appreciated

Total = 11 marks

ExamQuestion


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 totest ideas and develop theories,

1c how explanation of many phenomena can be developed using scientifictheories, models and ideas,

1d that there are some questions that science cannot currently answer, andsome that science cannot address,

3a recall, analyse, interpret, apply and question scientific information orideas,

4a about the use of contemporary scientific and technological developmentsand their benefits, drawbacks and risks,

4b to consider how and why decisions about science and technology aremade, 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 overtime and about the role of the scientific community in validating thesechanges.

The Examination Boards have interpreted these statements in slightlydifferent ways, so you will need to look carefully at the specificationyou are using.

The grid lists a number of topics collected from the various examinationspecifications, 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 icon on the relevant topic mapfor each chapter.


Possible opportunities Chapter Students’ page Page

How Science works 373–82

Ideas about proteins and vitamins 4 43, 51, worksheets (2) 104, 109

Ideas about blood circulation 6 80, worksheet 144

Use of hormones to control fertility 8 125–6

Work of Pasteur and Koch on microbesand disease 10 139, worksheets (2) 199, 200

Living conditions and life-style and the spreadof disease 143–4 worksheet 204

The discovery and development of penicillin 150, worksheet 207

The effects of cannabis on the body 11 162, worksheet 214

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, 261Cloning Dolly the sheep 219, worksheet 262Moral and ethical arguments for and againsthuman cloning 220

Economic, social and ethical issues of cloningand genetic engineering 14, 16 234, 256–9, worksheet 297

Ideas about DNA 16 241–3, worksheets (3) 282–84Rosalind Franklin 243, worksheet 285Mendel’s ideas and their recognition 247Ideas about genetically modified foods 261, worksheets (2) 298, 299

Fossils as evidence for evolution 17 270–71, worksheet 311Over-use of antibiotics and resistant bacteria 268Jean Baptiste Lamarck 266–9, worksheets (2) 306, 308Darwin’s theory of evolution 266–9, worksheets (2) 306, 308Alfred Russel Wallace 266–9, worksheet 307

Charles Elton 18 282–98, worksheet 322

Factory farming 19 316

Aspects of an increasing world population 20 320–21Conservation 334–5, worksheet 355Rainforest clearance 329, worksheets (2) 353, 354Rachel Carson 326–7, worksheet 348Biological and chemical methods ofpest control 326–7, worksheet 349

Eutrophication 326, worksheets (2) 351, 352

Food supplements 21 354–5Medicinal plants 357

How Science works : Changing ideas


Key Skills opportunities

The Key Skills Qualification requires students to show evidenceof 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 thesubjects 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’ Bookand full details of each component can be found at: www.qca.org.uk

About 35 opportunities for developing these Key Skills are markedwith a icon on the relevant topic map for each chapter.


Acknowledgements

Acknowledgement is made to the followingExamining Bodies for permission to reprintquestions from their examination papers:

EDEX Edexcel Foundation

OCR Oxford, Cambridge and RSAExaminations

AQA Assessment and Qualifications Alliance

Acknowledgement is also made to the following forvarious articles:The Daily Telegraph page 263The Guardian page 348

Illustration acknowledgementsAnn 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.331Hulton 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 theIllustrated London News (1897), 307 (photo by Reginald Haines reproduced inBibby’s Annual), 306 (unattributed photograph reproduced on a postcard);

Parke-Davis: p.144 (1959);Science Photolibrary: pp.104, 285.Picture research by: [email protected]


Using computers and ICTin Biology for YouThere are opportunities for using information andcommunications technology in Biology for You andthis section serves to highlight the best of them.Some of the resources you may well have, othersyou may consider obtaining and some need only atrip to the Internet to find today’s Biology. Theevidence for just how important Biology is hasnever been so accessible.

Sensors to collect dataHigh on the list of ICT resources are the sensorsthat link to a computer. A barometric pressuresensor is a surprisingly versatile device. Thissensitive pressure sensor responds to slightchanges at normal pressures and can be used inexperiments on osmosis and transpiration. It issensitive enough to act as a respirometer and apotometer allowing some very slow and smallchanges to be recorded over time. The key tosuccess is to ensure an air-tight seal and minimaldead space in the tubing.

Two popular sensors include those that respond topH changes and oxygen levels. A pH electrodeallows you to record the change as lipase digestsfat into fatty acids. An oxygen electrode, togetherwith a light sensor, allow you to monitor changes inan aquarium over several days. Using eithersuccessfully nearly always arises from carefulstorage of probes. Having a spare probe, thoughextravagant, helps reliability dramatically.

Multimedia software to visualise andunderstandToday’s Biology resources must surely includesimulation software. There are for example,software titles that animate biological processessuch as breathing and the heartbeat. In makingrecommendations we have selected those thathelp students’ understanding. You can often finduseful short animations hiding in other multimediatitles about the human body, in ‘electronic’encyclopaedias and by searching for ‘carbon cycleanimation’.

Information sourcesInformation sources like encyclopaedias and theInternet have a secure place in finding facts andrelevance. You will find text and pictures that gobeyond a book – including science news, currenthealth ‘scares’ and much to complement theBiology at Work sections. Think of an industry

where Biology is at work and for sure there exists apress release, a point of view and an alternativepoint of view. Use of the Internet is highlyrecommended for giving knowledge the relevancethat students thrive on. Use it for interest,homework and projects. Use it too for end-of-topicrevision, see, for example, BBC Bitesize atwww.bbc.co.uk. We have provided links to placesthat caught our interest and your own searches willsurely find more.

Handling dataA spreadsheet program is a helpful tool. It lets yourecord results do calculations and draw graphsdeftly. With just a bit more effort it lets you do themaths required to model a food chain, or showwhat we mean by exponential growth. Havingeveryday convenient access to a spreadsheetprogram really helps. Use it as a recording tableand a graphing program. Use it to help answer thequestions at the end of each chapter.

Display technologiesWhen there are specimens, techniques and muchmore to observe in Biology for You, displaytechnologies will add to students’ experience. Coreitems are cameras on desk stands variously called‘visual presenters’ or ‘document cameras’. Theyplug into a PC, projector or television so that all cansee a front bench demonstration or even a pagefrom a book. Use an adaptor to connect it to amicroscope and create an experience to share.Having the means to capture, photograph andvideo what you see opens the door to using imagesin worksheets, project work, and labellingexercises. One could for example, video ademonstration as it happens, play it back and thenask the class to recreate the commentary. Digitalmicroscopes share many of these features.Interactive whiteboards, which turn a screen into aspace where you can click, draw and store workwill surely find use in Biology. They help withdiagrams and labels in particular. You could, forexample, project a photograph of a plant cell andthen use the ‘whiteboard’ software to label theparts. You can trace around objects and makediagrams on screen. The connection betweenphotographs and diagrams is easily shown. Displaytechnologies make your resources large andgraphic. There may be no going back to the oldways.

Roger Frost, IT in Science consultancy and trainingEmail: [email protected]: www.rogerfrost.com


Cells and life processes

Chapter 1 CellsSpecialised cells

For hands-on or demonstration uses, Cells (fromSunflower Learning) offers photomicrographs ofmost of the examples needed at this level. Usefullyand unusually each image will ‘dissolve’ into alabelled diagram. Cells are the speciality of anInternet site (www.cellsalive.com), which canprovide visuals and animations for this topic. Thesite has photomicrographs of specialised cells thatcan, say, be placed on PowerPoint slides, labelledand used for discussion.

If you have it, Images of Biology (Nelson Thornes)is an Advanced Level title with many video clipsand photomicrographs of different types of cell thatwill be useful in this chapter. Also Bioscope forAdvanced Level (Cambridge–Hitachi) offers a‘virtual microscope’ with sample slides. A fun‘virtual microscope’ can be found at the Universityof Delaware www.udel.edu.

Cell size

A spreadsheet program can show the relationshipbetween surface area and volume; try thisparticularly if you have a display screen. First makea spreadsheet table like the table shown onpage 12 in the students’ book, but let the programdo the calculations. Show how changing the areaof one cube face affects the volume and surfacearea. For example, double the area of a cube faceand see how the volume changes in relation to this.Highlight the volume and area values and plot oneagainst the other on a graph.

Plant organs

Use a microscope with a camera attachment toshow the specimens on a display screen. This or adigital microscope will allow you to takephotographs of your specimens. Cells (fromSunflower Learning) offers ready-made examples.

Chapter 2 DiffusionDiffusion

The simulation software Diffusion (from SunflowerLearning) and Diffusion and Osmosis (fromPlato) offer the opportunity not only to visualisethese processes but also to investigate them. Thestudents see a membrane with solvent and soluteparticles on each side of it. They can changeconcentrations and they can change the size of thepores in a membrane. The simulation shows theparticles in motion and allows you to simulate thediffusion of a smell, the passage of materials in aroot hair and across the gut membrane.

Osmosis in plant cells

You can use a barometric (ie. sensitive) pressuresensor to monitor volume changes in osmosisexperiments. This method allows you to comparethe rate of osmosis between different liquids. Theset-up is outlined in Experiment 2.3 and theQuestions section. One group can use this set-up atthe start of the lesson as the class use the manualmethod. Connect the pressure sensor to Viskingtubing filled with sugar solution. A line graph showsthe progress of osmosis over time.

If you have a display screen Plants (fromSunflower Learning) features photomicrographsand animation of water transport in plants.

Chapter 3 EnzymesBreakers and builders

Very effective animation of how an enzyme workscan be seen in Enzymes (from SunflowerLearning). It shows well how an enzyme is notused-up and also why enzymes control oneparticular reaction. Also here, and useful for thenext section, is a virtual lab where pupils caninvestigate changes in pH, temperature andconcentration. For an explanation of enzymes seewww.howstuffworks.com.

The fastest enzyme in the west!

The heat from the breakdown of hydrogenperoxide assisted by catalase is considerable. Thischange can be monitored using a temperaturesensor and visualised on a graph. It is surprisinghow high a temperature this reaction can reach.You need a couple of temperature probes placed intest-tubes, each containing hydrogen peroxide.Start recording and add a piece of potato to oneand chopped potato to the other, and then note thechange as two traces find their way up the screen.The method lends itself well to an investigation intoenzyme activity.

Hotting up

Enzyme experiments can be monitored usingcomputer sensors, giving the advantage of showinga rate of change. You can record the rate at whichamylase acts on starch by measuring the light levelusing a light sensor. The rate of the reaction showsas the slope of a graph on screen. You can monitorhow fast lipase turns milk fat into fatty acids. Place apH electrode into a mixture of milk and lipase, addsodium carbonate to make this slightly alkaline andthen place in a water-bath. The pH should decreaseover the next half hour. Visit the National Centre forBiotechnology at www.ncbe.reading.ac.uk for asuitable source of lipase and other enzymes.

Enzymes and pH

The enzyme simulation Enzyme Lab (fromNewbyte) as well as Enzymes (from Sunflower


Learning) offer the ability to change all kinds ofvariables in software and to see the results on agraph. Here you might show what affects enzymereactions graphically and efficiently look at avariety of parameters in one session.

Enzymes in industry

For project work, take a look at the fascinating usesof enzymes in industry. Visit Novozymes atwww.novozymes.com to find first-handinformation.

Humans as organisms

Chapter 4 Food and digestionFood and energy

You can use a temperature sensor in Experiment4.5 to measure the temperature rise as a peanutburns. You can see the temperature rise as thepeanut burns, and also, interestingly, gain extraprecision in your measurement.

How much energy?

Diet analysis programs give a detailed breakdownof the nutrients in your diet and show how wellyour intake relates to the recommended dailyamounts. Diet Analyser (from Plato) allows you todo this very efficiently. Use it both to compare theneeds of different people and to compare theenergy content of different foods. Or more simply,use it to compare the energy content of differenttake-away meals – the students enter the details fora pizza meal, a burger meal and a fried chickenmeal.

You may prefer to use a spreadsheet program tocalculate the ‘Energy content of different foods’ inthis chapter.

Digestion

For animation of what happens in the gut seeDigestion (from Sunflower Learning) or DigestiveSystem (from Plato). Ideas such as peristalsis andchemical digestion are clearly shown.

Chapter 5 Breathing and respirationMeasuring the heat energy from germinatingseeds

In Experiment 5.1, you can use a sensor to measurethe temperature rise as seeds germinate anddisplay this clearly as a graph on screen. A datalogger will take readings through the day and night,adding to the precision you could normally achievein the experiment.

How fast?

Monitoring pressure changes with a computer notonly shows the change but also the change overtime. You can make a respirometer with a slightvariation of the manual procedure for Experiment

5.7. By using the very sensitive barometric pressuresensor in place of a capillary tube, you can obtainbetter precision and a more graphic result.

Two-way trip to your lungs

For animation to illustrate the process of breathingsee Breathing and Respiration (from Plato). Likea live textbook diagram, here are close-ups to useto explain breathing. This includes animatedcameos of the action of the diaphragm, gas andblood flow in the lungs, alveolus, heart andmuscles. Controls within the software allow you tosee the effects of exercise.

Deeper into your lungs

Animation is available to teach about what happensin the lungs. Alveolus (from Plato) shows expandingair sacs, gas exchange in the lungs, the diffusion ofoxygen and carbon dioxide. These visuals help toshow how we move carbon dioxide out of the bodyand how we obtain oxygen from the lungs. See alsoCirculation (from Sunflower Learning) which alsoanimates blood flow in the alveoli.

Take a deep breath

To examine the effect of exercise on your breathingrate, as in Investigation 5.11, students can use abreathing sensor. They might use a stethograph,which is a corrugated tube that stretches round thechest and transmits chest movements to a pressuresensor. This shows the frequency and depth ofbreathing. To measure lung volumes and vitalcapacity, they might connect a position sensor to aspirometer, and the sensor can record themovement of the spirometer lid.

Respiration without oxygen

You can monitor the rise of bread dough, forExperiment 5.13, by resting the lever arm of aposition sensor on the surface of the dough. Youmight set this up alongside the class experimentand review the results towards the end of thelesson. For experiments concerning fermentation,sensors which measure oxygen or pH can be left inthe ferment to provide evidence that changes aretaking place.

Muscles without oxygen

See the animation of oxygen uptake in muscle inBreathing and Respiration (from Plato). Thissoftware title also allows you to show the effectsof exercise on muscle. See also Circulation(from Sunflower Learning) which also covers thistopic.

Chapter 6 Blood and circulationThe double pump

For an animation of the heart showing the doublecirculation see Circulation (from SunflowerLearning) or Heart (from Plato). Circulation


features good animation of how muscle assistscirculation in the vein.

Heart action

For an animation of the heart showing the heartcycle, see Circulation (from Sunflower Learning)or Heart (from Plato). These titles offer an insideview of the heart, which can be run as slowly asrequired.

Seeing your pulse trace on the computer screencan be memorable, and various sensors allow youto do this. You will find pulse and ECG sensorswhich record how the heart responds to, say,caffeine stimulation. Relatively inexpensive sensorscan be found in high-street outlets.

Heart disease

For information and project work, these websiteson 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) containsmicroscope pictures of various blood cells tohelp complete the picture of the heart andcirculation.

Chapter 7 HomeostasisKeeping things steady

Electronic control systems are good analogies ofhuman control systems and can be used todemonstrate a point about temperature regulation.The modular microelectronics kits, often used inelectronics courses, can be handy here. Byconnecting together a couple of modules you canquickly make a working model of homeostasis.

Controlling blood sugar

The software title Blood Sugar (from Plato) showsthe feedback loops that control blood glucose. Itprovides an interactive model of two humans, onenormal, one diabetic, and allows you to examinewhat happens when they eat and exercise.

For further information about diabetes, itstreatment and approaches to its prevention, seeBBC Health at www.bbc.co.uk/health/

Inside the kidneys

Kidney (from Plato) animates many of the ideas inthis section: the flow of salts, the absorption ofwater and the role of hormones.

Chapter 8 Control and coordinationYour reflexes

You can use computer light gates for measuringyour reaction time very effectively. You can easily

see how the reaction time improves withpractice.

Your nervous system

Software titles about the human body havegraphics and animation you can show to illustratereflex arcs. The Ultimate Human Body (from AVP)has a section on the nervous system. The sciencesection of the BBC website www.bbc.co.uk has anervous system game.

Your senses

Computer sensors such as the light sensor and thesound sensor make interesting analogies to explainhow the eye and the ear work. Set up a sensor witha data-logging system and show its response on abar graph.

See also the diagrams and animation at HumanAnatomy Online www.innerbody.com. Inparticular see the ear and eye in a section on the‘Nervous System’. The science section of the BBCwebsite www.bbc.co.uk has an interactive sectionabout the senses.

Correcting eye defects

One of the best explanations of long and short sightcan be found in Crocodile Physics (fromCrocodile Clips). The optics section in thissoftware has a model eye where you can alter acorrecting lens and see where the light rays cometo a focus.

Ovulation and the menstrual cycle

For animation showing the cycle, the interplay ofhormones and the effect of the pill, see MenstrualCycle (from Plato). More animation, with a goodday-by-day graph can be found at the BBCwebsite. It can be found via a search atwww.bbc.co.uk.

Chapter 9 Support and movementJoints

Your can use graphics and animation about thehuman body to show the workings of differenttypes of joint. You will find diagrams at HumanAnatomy Online www.innerbody.com. (see, forexample, the Muscular System). Compare this withwww.bbc.co.uk/science/humanbody which has aninteractive diagram of the skeleton and muscles.

Chapter 10 DiseaseInformation on health can always be found online,for example, see the section on the immunesystem at BBC Health www.bbc.co.uk/health. Asearch at this site yields information on all kinds ofdisease, while the World Health Organisation atwww.who.int has statistics and advice on currentpandemics. Photographs and artwork can be foundin the library section at The Wellcome Trust


www.wellcome.ac.uk. See alsowww.schoolscience.co.uk for information on thehistory of medicine, diseases, asthma andimmunity. For detailed information on the life cycleof the malarial parasite and prevention, treatmentand diagnosis of malaria, see for examplewww.rph.wa.gov.au/malaria.html.See also Access Excellence – the national healthmuseum at www.accessexcellence.org.

Chapter 11 DrugsDrugs

The Internet is the first port of call for facts on drugsbut steer towards reliable sources such as theNational Drugs Helpline known as TalktoFrankwww.talktofrank.com. The BBC at www.bbc.co.ukoffers drug information on various levels includinghealth, news and crime. Smoking is covered by ASH(Action on Smoking and Health) www.ash.org.uk.See also www.schoolscience.co.uk for informationon abused drugs.

Smoking and health

To pick up facts about the chemicals in smoke, andtheir effects on the body, have the class visit thisInternet site which you might use for aninformation-collecting exercise:● ASH (Action on Smoking and Health)

www.ash.org.uk

Plants as organisms

Chapter 12 Feeding in plantsRaw materials for photosynthesis

For animation of what happens in photosynthesis,as well as micrographs of numerous cells, seePlants (from Sunflower Learning). Animationshowing the stoma opening and a cross section ofa leaf will be particularly relevant.

You can use an oxygen sensor and a light sensor toshow how the rate of photosynthesis changes withlight level. You might also monitor the light andoxygen levels in an aquarium over several days andlook for a pattern between the two measurements.You can use a pH sensor in place of the oxygensensor – a pH electrode placed near the plantleaves will be sensitive to a local depletion ofcarbon dioxide during photosynthesis. Sampleresults are available at www.rogerfrost.com.

Products of photosynthesis

Software titles can be found that simulateExperiment 12.6, where students watch bubblesappearing from pondweed. Both Photosynthesis(from Plato) and Photosynthesis (from SunflowerLearning) can be used as a follow-up to theexperiment either as a demonstration or a classactivity. The simulation takes the experiment a

stage further by offering controls to change thetemperature, the intensity of the light and its colour.

Fertilisers

For a homework or revision activity see the factsheet with questions on the importance of N, P, K inplants at Schoolsnet www.schoolsnet.com.

Chapter 13 Plant transportTranspiration

For animation showing the stoma opening, as wellas micrographs of numerous cells, see Plants(from Sunflower Learning).

In addition to Experiment 13.3, you can monitorloss in mass using a computer-linked balance.Another reliable approach is to place a plant in apolythene bag with a humidity sensor and see howthis changes over time. The method isstraightforward and worth a try.

Measuring transpiration

A barometric pressure sensor (narrow rangepressure sensor) is able to show the effect of windon transpiration, often with immediate results. It iseasy to set up. Also a plant stem can be connectedto this very sensitive sensor using a rubber tube;the effect of a desk fan is seen as a trace on acomputer screen.

Chapter 14 ReproductionUseful here are the diagrams at Human AnatomyOnline www.innerbody.com where you might seethe reproductive system. Compare this withwww.bbc.co.uk/science/humanbody which has aninteractive diagram of the reproductive system.

Cloning

Intensive food productionFor another viewpoint on food production seeCompassion in World Farming www.ciwf.org. Lookwithin to find resources on cloning, geneticengineering and selective breeding. More can befound at Global Change where news, lecture andvideo can be found in quantity onwww.globalchange.com/cloning. This is a fast-moving area of opinion where a search onnewspaper sites for ‘cloning’ or ‘cloning links’yields results.

Chapter 15 VariationClassification

‘Identification keys’ and ‘Identifying organisms’ aresimple classification tools that you can use on awhiteboard. They can be found atwww.echalk.co.uk.

Animals UK (from Gatekeeper Educational) issoftware to identify common British animals thatstudents might find near school. It features a


database with 150 species including butterflies,other land invertebrates, pond life, amphibians,reptiles, birds and mammals. Plants UK (fromGatekeeper Educational) similarly features 54species of wild flower and 64 species of trees,shrubs and grasses.

See the Field Studies Council www.field-studies-council.org which run field centres around the UKand publish fold-out identification charts. SeeBiomedia at http://ebiomedia.com for an exerciseabout Animal Phyla.

Chapter 16 InheritanceMitosis

Having convenient access to video is surprisinglyhelpful. Mitosis is easily visualised with the help ofMitosis and Meiosis (from Plato). This particulartitle allows you to run back and forth throughmitosis, which helps when explaining the process.That aside, clips of mitosis can be found with asearch of the Internet. For example, search at theUS Public Broadcasting Service www.pbs.org,School Science www.schoolscience.co.uk or theBBC www.bbc.co.uk for free animation. Anothersoftware resource to consider is Mitosis andMeiosis: An Interactive Approach (fromIllumination Educational Software) which similarlyanimates 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, andsee the variation that meiosis makes possible. For aclass exercise, you might copy the stages ofmeiosis into PowerPoint slides. The class can sortthe slides and annotate them.

Genes in action

The software simulation Inheritance (from Plato)ably shows how characteristics are inherited. Itallows students to experiment with the inheritanceof blood groups, tongue rolling or haemophilia, andto see how the genes pass from parents tograndchildren. The software animates the pairingof genes and offers opportunities to investigate agood range of scenarios.

Two titles aimed at Advanced Level are useful ifyou have them. Drosophila Genetics and PeaPlant Genetics (from Newbyte) simulate almostunlimited experiments with fruit flies and peaplants respectively. Used here, perhaps just as ademonstration, they help make many of theteaching points in this section.

Find out about research into the human genome atThe Wellcome Trust Sanger Institute atwww.sanger.ac.uk. Search the Internet and youcan find Eureka Science with an interesting way to

explain genes at www.eurekascience.com. Startwith www.dnai.org, which although this is oftenbeyond the syllabus, features stunning animationand video. Search further and you will findacademic and everyday applications of genetics,for example, USA Genomes www.ornl.gov/hgmis;Advanced therapies www.celera.com; Watchdogon genetic technologies www.genewatch.org; USAHuman Genome Research www.genome.gov;Nowgen Genetics Knowledge Parkswww.nowgen.org.uk; European Initiative forBiotechnology Education www.eibe.info.

Chapter 17 EvolutionEvolutionThe BBCs pages on ‘Human Beginnings’ hasbackground material on evolution that studentsmight examine for homework. This is atwww.bbc.co.uk/sn/prehistoric_life. PublicBroadcasting in the US offers information and ashort tutorial on evolution www.pbs.org.

Selection in actionSelection lends itself well to software models andNatural Selection – Frogs (from Newbyte) involvesstudents in the predation of coloured frogs. Theycan add a poison gene into the population orintroduce frogs that mimic poisonous frogs. Themodel works as a game to hunt frogs, however thetreatment is clever and effective. Another title in thisseries is Natural Selection – Beetles (fromNewbyte) which deals with beetle colours.

Peppered mothsNatural Selection – Peppered Moths (fromNewbyte) puts students in the role of a birdpredating upon different moths. As the forestchanges through industrial pollution it becomeseasier to catch the white moths. As a resultstudents effectively work through the story of thepeppered moth. This is another simple but veryeffective teaching tool. A similar tool to purchasecan be found at www.echalk.co.uk.

Living things and their environmentChapter 18 Adaptation andcompetitionHow populations growPredator Prey (from Sunflower Learning) andCreatures (from Future Skill Software), whichprovide models of foxes, rabbits and plants, wouldbe very useful here. As the model runs you see thenumber of coloured squares increase anddecrease. Parameters such as the level of sunlightand death rate can also be changed. This softwarecan make a good contribution to this section. Alsosee UK Countryside & Nature Conservationwww.naturenet.net; Kew Gardenswww.kew.org; WWF www.wwf.org;


United Nations Environment Programme WorldConservation Monitoring Centrewww.unep-wcmc.org.

Predator–prey cyclesPredator Prey (from Sunflower Learning) andCreatures (from Future Skill Software) are bothmodels of foxes, rabbits and plants and areparticularly useful here. Several variables can bechanged. The software plots a graph to showpopulation changes over time.

Chapter 19 Energy and nutrienttransferPyramids of biomassPredator Prey (from Sunflower Learning) andCreatures (from Future Skill Software), which offermodels of foxes, rabbits and plants, are particularlyuseful here, as the software plots a graph to showpopulation changes over time.

You can also use a spreadsheet program to handlethe numbers in a food pyramid. It requires a tablewith a list of animals (eg. owls and shrews) in thefirst column and their proportions in the nextcolumn (eg. 1, 10). A third column shows theirmass, while the last column calculates the totalmass. The resulting model allows you to calculatethe loss of energy through the food chain.

Food websStudents can build food webs from organismsprovided at the Gould Leagueww.gould.edu.au/foodwebs/kids_web.htm.

Food Webs: Ponds (from Newbyte) is an intriguingpiece of software that allows you to construct foodchains and webs using a set of organisms. You runthe model, which can be as simple or complex asneeded to see it played out as a graph on screen. Allmanner of factors, such as phosphate levels, nitratelevels and temperature affect the web. The foodweb can be adapted to model a local environment.

Nutrient cycling

Carbon cycleEven the slightest amount of animation will helpexplain the carbon cycle. Search at USEnvironmental Protection Agency www.epa.gov tofind one example. The ‘Ecology’ section atPurchon’s www.purchon.com offers facts anddiagrams on the carbon cycle – and muchmainstream Biology. A detailed treatment withuseful diagrams, for library projects, for example,can be found at Earth Observatoryearthobservatory.nasa.gov. Another example is atBBC Bitesize at www.bbc.co.uk.

Nitrogen cycleRevision notes about the nitrogen cycle and morecan be found in the science section at

www.learn.co.uk. Another example is at BBCBitesize www.bbc.co.uk.

Intensive food production

For another viewpoint on food production seeCompassion in World Farming www.ciwf.org. Lookwithin the Education section to find resources onethics and farming, animal sentience, and an ‘eatless meat’ campaign.

Chapter 20 Humans and theenvironmentThe greenhouse effect

An animated greenhouse effect with statistics on itsimpact is found by searching at the BBC News sitenews.bbc.co.uk.

Conservation

Websites of conservation organisations include thefollowing:The National Trust www.nationaltrust.org.uk; TheCouncil for National Parks www.cnp.org.uk;Natural England www.naturalengland.org.uk hasinformation on National Nature Reserves (NNR)and Sites of Special Scientific Interest (SSSI) andHeritage Coasts. The Department for Environment,Food and Rural Affairs’ Farm Woodland Scheme isat www.defra.gov.uk; The Royal Society for theProtection of Birds www.rspb.org.uk.

Biotechnology and behaviour

Chapter 21 BiotechnologyBiotechnology

Useful stepping stones on the Internet are theEuropean Initiative for Biotechnology Educationwww.eibe.info and Access Excellence – thenational health museum atwww.accessexcellence.org.

Yoghurt manufacture

Monitoring the souring of milk with a data loggeryields results worthy of discussion and is perhapsone of the easiest of procedures to attempt. Place atemperature probe and good pH probe in a beakerof milk, cover with foil and ensure the data loggeris powered. Record for up to 48 hours to see howthe pH is at first buffered by the milk proteins buteventually changes.

Sewage treatment

With biotechnology so pervasive, students can gaina flavour of its many applications through projectwork on the Internet. Websites of all kinds can befound with a general search. For example,information for a project on water treatment can befound at www.theguardians.com.


Biofuels

Information on biomass fuel can be found, forexample, at US Energy Information Administrationwww.eia.doe.gov.

Chapter 22 BehaviourAnimal behaviour

BBC Science and Nature covers a range of animalbehaviour topics in a digestible format: start at

www.bbc.co.uk. See also National Geographic atwww.nationalgeographic.com. Anotherspringboard to resources is the education sectionat the US Animal Behaviour Societywww.animalbehaviorsociety.org.


ResourcesFor 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, GreatWestern 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 usingcomputer 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 inscience (ISBN 0 9520257 1 X)The IT in Secondary Science Book of Data loggingand Control: a planning guide, with examples, forusing 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 andTechnology Agency, Millburn Hill Road,Science Park, CV4 7JJ. Tel 024 7641 6994.Fax 024 7641 1418. www.ictadvice.org.ukwww.becta.org.uk

● Crocodile Clips – software, 43 Queensferry StreetLane, Edinburgh, EH2 4PF. Tel 0131 226 1511.Fax 0131 226 1522. www.crocodile-clips.com

● Roger Frost & IT in Science – training, RussetHouse, 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), WaldronDown 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, ThamesDitton, KT7 0HN. Tel 0845 1300 680.Fax 0845 1300 681. www.sunflowerlearning.com


Answers to Further QuestionsOn the following pages are the detailed Answers and Mark Schemes for eachof the Further Questions in Biology for You.

The Answers have been prepared by a Chief Examiner using the mark schemespublished by each Examination Board.

� You will find these sheets useful when marking the students’ homework, orwhen going over the Further Questions in class.You may also find it useful to glance at the Answer Sheet before settinghomework, to see how much work is involved in answering a question.

� The sheets are also available for you to photocopy and hand out to thestudents if you wish (perhaps as part of a Revision Programme).You may need to explain the Mark Schemes to the students, so that theyappreciate for example that in some answers the mark is for the idea intheir own words (not necessarily the exact words shown) whereas in otheranswers the number and unit must be exactly correct.

Model AnswersWe also provide, on pages 49–67, some photocopiable GCSE questions, eachset 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 areparticularly useful in the revision period before the final examination – if usedearlier, they may appear too daunting.


� Cells1 (a)ii 1 mark each for:

plant cells have chloroplasts;plant cells have a cell wall;plant cells have a large vacuole.

(b) (i) 1 mark for the idea that it controls theactivities of the cell.

(ii) 1 mark for the idea that it strengthens thecell.

(iii) 1 mark for the idea that it is where most ofthe chemical reactions take place.

(iv) 1 mark for the idea that it controls thepassage of substances in and out of the cell.

(c) (i) 1 mark for chlorophyll.(ii) 1 mark for the idea that it is essential in the

reaction (photosynthesis) which producesfood for all animals and plants.

Total 9 marks

2 1 mark each for:E;I;A;G;C;D;B;F.

Total 8 marks

3 (a) 1 mark for each correct pair:palisade cell B 3root hair cell C 1sensory neurone D 4white blood cell A 2

(b) 1 mark each for two ideas:palisade cell – contains chloroplasts forphotosynthesis;root hair cell – has large surface area forabsorption of water or mineral ions;sensory neurone – elongated shape enablesit to carry impulses over long distances;white blood cell – can change its shape toengulf microbes.

Total 6 marks

� Diffusion4 (a) 1 mark for each of the following ideas:

water enters;by osmosis;from high concentration of water moleculesto low concentration of water molecules.

(b) 1 mark for tick in box stating less absorbedand higher percentage increase.

Total 4 marks

5 (a) 1 mark each for:(i) yellow or straw colour;(ii) blue / black colour.

(b) 1 mark for each of the following ideas:starch has been broken down to sugars;which do not react with iodine solution.

(c) (i) 1 mark for each of the following ideas:boil the mixture from A with Benedict’ssolution;an orange colour would prove the presenceof sugars;

(ii) orange colour.(d) 1 mark for the idea that the amylase is

denatured.Total 8 marks

6 1 mark for each of the following ideas:sea water contains salt;the salt concentration of the sea water ishigher than the cell solution;water moves from a region of high waterconcentration to a region of lower waterconcentration;through the partially permeable membranesof the air sacs;by osmosis / diffusion.

Total 5 marks

Further questions on Cells and life processes pages 38–9


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 verticallyand an x-axis scale from 0 to 1.5 arbitraryunits filling graph paper horizontally;all points correctly plotted;line of best fit drawn.

(ii) 1 mark for correctly reading the arbitraryunit where the line crosses 0% change inmass.

(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) 1 mark for rises.(b) 1 mark for each of the following ideas:

the solution inside the funnel is moreconcentrated than the solution outside;there is a net flow of water molecules fromoutside to inside;through the partially-permeable membrane;due to osmosis.

Total 5 marks

� Enzymes9 (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 possiblealternatives.

(b) 2 marks for all points plotted accurately(must be ��

12� 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 frompupil’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 / productcan be absorbed / product can enter blood;or protein cannot pass through gutlining / 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 asindependent variable and time taken todigest sucrose as the dependent variable;2 marks for points plotted accurately.

(ii) 1 mark for each of the following ideas:as sucrase concentration increased, timetaken to digest sucrose decreased;correct reference to numbers in support.

(c) (i) 1 mark for idea of near optimumtemperature 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 hightemperature;because enzymes are denatured.

Total 14 marks

11(a) 1 mark for enzyme.(b) 1 mark for the lactase can be used many

times / the lactase is not lost.1 mark for the milk product does not containlactase.

(c) 1 mark for idea warm the milk / surroundthe tube with a heated jacket / similarsuggestion.

(d) 1 mark for the enzyme / protein is denatured.Total 5 marks

pages 40–41 Further questions on Cells and life processes


� Food and digestion1 (a) (i) 1 mark for 31;

(ii) 1 mark for obese;(iii) 1 mark for 7 kg.

(b) 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 stillgrowing but Neil is not.

Total 7 marks

2 (a) 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) 1 mark each for:(i) beefburger;(ii) 18.0 g;(iii) liver (or muscle);(iv) glycogen.

(b) 1 mark for each of the following ideas (to amaximum 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 inblood vessels;vegetable burger has more fibre;therefore lowers cholesterol or preventsconstipation.

Total 8 marks

4 (a) 1 mark for fatty acids and glycerol.(b) 1 mark for each of the following ideas:

emulsifies fats or breaks down large dropsinto smaller droplets;which increases the surface area of fats;for lipase (or enzymes) to act upon.

(c) 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 respiration5 (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 forrespiration could be given);more rapid respiration releases more energy.

(b) 1 mark for each of four of the followingideas:increased blood circulation near bodysurface/skin/reference to dilation ofarterioles/vasodilation/increased bloodcirculation in capillaries (in skin);increased loss of heat from skin surface (byconvection);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 formore muscle contraction (for faster running);releases more energy.

Total 10 marks

6 (a) 1 mark for trachea or windpipe.(b) 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 ofdiaphragm muscles.

(f) (i) 1 mark for 16 (4 � 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

12

Further questions on Humans as organisms pages 171–2


7 (a) 1 mark each for two of:bronchitis;emphysema;lung cancer.

(b) (i) 1 mark for 2;(ii) 1 mark for each correct row:

CO2 high low;O2 low high.

(c) (i) 1 mark for white blood cell;(ii) 1 mark for one of:

engulfs microbes;produces antibodies to kill microbes;produces antitoxins to neutralise microbialproteins.

Total 7 marks

� Blood and circulation8 (a) (i) 1 mark for 40;

(ii) 1 mark for 3.(b) (i) 1 mark for transport of oxygen (or transport

of some carbon dioxide);(ii) 1 mark each for two of the following ideas:

contain haemoglobin (combines with andreleases the oxygen, or carbon dioxide);large surface area / biconcave shape;no nucleus.

(c) 1 mark for the idea that the carbonmonoxide combines with the haemoglobinso less haemoglobin is available to transportoxygen.

(d) (i) 1 mark for the idea that red blood cells haveno nucleus;

(ii) 1 mark for 5 billion (5 thousand million or5 000 000 000);

(iii) 1 mark each for the following steps in thecalculation:1 cm3 contains 5 billion (see working above)so 5000 cm3 contain 25 thousand billion;but average life of a red blood cell is about100 days, so average number of red bloodcells that have to be made each day is 0.25thousand billion. (Note: It would probablybe easier to convert this to powers of 10, tohandle all the zeros ie. 0.25 � 1012.)

(e) (i) 1 mark for each of the following ideas:bone marrow from near relative is morelikely to be of same tissue type;more compatible or not generate an immuneresponse;

(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 tore-establish.

Total 16 marks

page 173 Further questions on Humans as organisms


9 (a) 1 mark each for:axes labelled correctly;all plotted correctly;

(b) 1 mark for each of the following ideas:increases with age up to 64;then drops with age.

(c) 1 mark for each of the following ideas:rapid increase;higher than men;reasonable suggestion eg. caused bymenopause.

(d) (i) 1 mark for idea of restricting blood flow;(ii) 1 mark for idea of stopping blood flow to

heart muscle;1 mark for consequence eg. less oxygen toheart muscle.

Total 10 marks

10(a) 1 mark for each of the following ideas:advantage is less drugs needed;as less chance of rejection;disadvantage is it needs a power supply;and may be larger than normal heart.

(b) 1 mark for each of the following ideas up toa maximum of three:transport problems over a large distance;may find out that it is available too late orheart must be transplanted quickly;may be too ill for surgery;heart may not be the correct tissue type.

(c) (i) 1 mark for each of the following ideas:1 mark for good argument for eg. saveslives;1 mark for good argument against eg. is thedonor beyond help;

(ii) 1 mark for good explanation either for oragainst eg. more donor organs wouldbecome available;1 mark for choice made for or against.

Total 11 marks

11(a) 1 mark for 84.(b) 1 mark for the idea that his pulse showed

the smallest increase during exercise.(c) 1 mark for each of the following ideas:

all the students should exercise in the sameway;they measure their pulse more frequentlyafter exercise.

Total 4 marks

� Homeostasis12(a) 1 mark for each of the following ideas:

increased;rate of respiration.

(b) 1 mark for each of the following ideas:much of the energy released duringrespiration is released as heat;which causes the body temperature toincrease.

(c) 1 mark for the idea that a regulatorymethod, eg. sweating, is switched off by thechange in body temperature which it bringsabout.

(d) 1 mark for each of the following ideas:it is converted to glycogen;which is stored in the liver or muscles.

(e) (i) 1 mark for each of two of the followingideas:insulin is produced by the pancreas inresponse to the increased blood sugar levelafter each meal;this insulin is then destroyed by the body;the single dose would be effective for one ortwo meals only.

(ii) 1 mark for each of the following ideas:either lower blood sugar as a result ofexercise;would lead to a decrease in insulinproduction.or lower blood sugar as a result of exercise;would lead to an increase in glucagonproduction.

Total 11 marks



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 inthe 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 inurine must be 1500 cm3

(2500 cm3 � 1000 cm3).(ii) 1 mark for each of the following ideas (or

the converse arguments):when blood more concentrated (less waterin the blood);more water reabsorbed from the kidneys /more water passes from kidney filtrate backinto the blood;at collecting duct.(Could also make reference to moreADH / antidiuretic hormone being secretedinto blood.)

(c) 1 mark for each of the following ideas:urea passes out of blood into liquid (indialysis 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 forperson to be out of action / avoids need forregular 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 toaward a mark for suitable ethicalconsideration.)

Total 14 marks

14(a) (i) 1 mark for protein;(ii) 1 mark for idea that protein molecules are

too large (to pass through walls inglomerulus).

(b) 1 mark for idea that water is reabsorbed /passes back from filtrate into blood (so ureabecomes more concentrated in the liquid inthe bladder).

(c) (i) 1 mark each for three of the followingideas:blood passes into dialysis tubing (of dialysismachine);tubing differentially permeable;tubing surrounded by liquid;composition of this liquid is the same as thatof blood except there is no urea;urea (plus other waste products) pass fromblood to dialysis liquid;by diffusion;along concentration gradient;reference to flow of liquids in oppositedirections / countercurrent flow;reference to method of attachment or linkingdialysis tubing into blood vessels of person.

(ii) 1 mark for concentration of 0.35%;then 1 mark for explanation with the ideathat there is then no net flow of salts acrossthe membrane / dialysis tubing (from bloodto fluid or fluid to blood) / composition ofblood 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 ADHcirculating in the blood plasma / it takestime for this ADH to be used.

Total 9 marks

pages 175–6 Further questions on Humans and organisms


� Control and coordination16(a) 1 mark for reflex arc.

(b) 1 mark for the idea of contraction.(c) 1 mark for the idea of less time taken to

respond as brain not involved and so lessdamage likely.

(d) 1 mark for each correct answer of D, C andA.

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 highestaround 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

� Disease18(a) 1 mark for each of two of the following

features:no nucleus or DNA / chromosome / geneticmaterial 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 andwhat 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 / denaturesprotein / denatures enzyme.

(c) (i) 1 mark for kills / destroys bacteria orprevents growth of bacteria;

(ii) 1 mark for each of two ideas from:bacteria may be resistant / immune(treatment is futile) or bacteria would not bekilled;may select for resistant type;may cause increased incidence of resistanceor penicillin less effective in the future;sore throat may be due to a virus so thepenicillin would not work.

Total 7 marks



19(a) 1 mark each for:(i) virus;(ii) bacteria;(iii) protozoa;(iv) fungus.

(b) 1 mark for each of the following ideas:blood contains white blood cells that destroypathogens (accept idea that blood clots toprevent entry of pathogens);hydrochloric acid kills bacteria that enterwith food and drink;mucus membranes trap bacteria andprevent entry to lung;skin acts as a barrier to pathogens.

Total 8 marks

20(a) 1 mark for idea that dirty clothes /equipment / hands / any sensible sourceeg. surgeon, floor passed bacteriaor ease of entry of bacteria during operations.

(b) 1 mark for fewer died;1 mark for an indication of reduced numberor proportion eg. 20% of previous deaths /down by 2400.

(c) (i) 1 mark for dialysis (machine) or kidneymachine;

(ii) (specially chosen kidney) 1 mark for similartissue type / same blood group;(irradiation of bone marrow) 1 mark for tostop white blood cell production;(treated with drugs) 1 mark for suppressimmune system;(sterile conditions) 1 mark for avoidexposure to pathogens / infection.

Total 8 marks

21(a) (i) 1 mark for digestion / hydrolysis;(ii) 1 mark for the idea that they are made into

proteins.(b) (i) 1 mark for lymphocytes (a type of white

blood cell);(ii) 1 mark for the following ideas:

HIV infection;damage to bone marrow (site of protectionof lymphocytes);stress, etc.;

(iii) 1 mark each for two of the following ideas:transplant introduces ‘foreign’ cells;immune system / T cells recognise these;attack / destroy cells of transplanted organ /rejection.

(c) 1 mark for the idea that antibodies pass(through the placenta) from the mother tothe baby / via colostrum / mother’s milk.

(d) (i) 1 mark for 10 weeks;(ii) 1 mark for passive;

1 mark for the idea that this is because theantibodies are given to the person ratherthan being produced within the person.

Total 10 marks

� Drugs22(a) (i) 1 mark for to test for side effects;

(ii) 1 mark for thalidomide was only tested as asleeping pill;1 mark for thalidomide was not tested onpregnant women.

(b) 1mark for each of five of the following ideas:cannabis is not a pure substance;cannabis contains chemicals which might betoxic;the patient could become addicted;cannabis might cause the patient to try otherdrugs such as heroin;cannabis might have other unwanted sideeffects;cannabis is an illegal drug;cannabis has not been tested in thelaboratory;any other different valid reason.

Total 8 marks

23(a) 1 mark for each of the following:an x-axis scale from 0–18 litres filling graphpaper horizontally;a y-axis scale from 0–35 deaths per 100 000people per year filling graph papervertically;all bars correctly plotted;bars labelled by country.

(b) 1 mark for the idea that the higher theamount of alcohol consumed, the higher thenumber of deaths from liver disease.

(c) 1 mark for the idea that some other factorcould be causing deaths from liver disease inGermany eg. diet.

Total 6 marks

24(a) 1 mark for each of the following ideas:emphysema cases increase with an increasein the number of cigarettes smoked per day;tuberculosis cases are unaffected by thenumber of cigarettes smoked per day.

(b) 1 mark for each of the following:cancer; heart disease.

Total 4 marks

25(a) (i) 1 mark for the idea that the more alcoholintake the greater the blood alcohol level;

(ii) 1 mark for the idea that smaller peoplehave a greater blood alcohol level thanbigger people;

(iii) 1 mark for the idea that females have agreater blood alcohol level than males.

(b) (i) 1 mark for each of the following:lines both labelled;one scale covers half the grid and is linear;axes correct with alcohol consumed per houras independent variable and blood alcohollevel as the dependent variable;2 marks for points plotted accurately.

(ii) 1 mark for answer in the range 6.2 to 6.6;(iii) 1 mark for 125.

(c) 3 marks for correctly completing table withcerebellum; cerebrum; and medullaoblongata.

Total 13 marks

pages 178–80 Further questions on Humans as organisms


� Feeding in plants1 (a) 1 mark for one idea eg.

flat – to capture as much light energy aspossible;contain chlorophyll – to capture light energy.

(b) 1 mark for each of the following ideas:(i) to allow light to penetrate to the palisade

cells;(ii) for maximum absorption of light (which

comes from above);(iii) gases enter via the stomata and from here

must diffuse quickly to the palisade cellswhere most photosynthesis occurs.

(c) 1 mark for chlorophyll.(d) 1 mark for each of the following ideas:

(i) increase – since there will be moreavailable light;

(ii) decrease – the higher the temperature, thefaster the chemical reactions inphotosynthesis.

Total 7 marks

2 (a) 1 mark for the idea that it is to prevent lightreaching 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 toproduce starch.

Total 5 marks

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 byphotosynthesis;the amount falls as it is converted intostarch for storage or into other materials forgrowth;

(ii) 1 mark for the idea that the plants aregrowing so there will be more leavesproducing sugars;

(iii) 1 mark for the idea that it was a dull day sothere was less photosynthesis.

(c) 1 mark for each of the following ideas:the temperature would increase, soincreasing the rate of photosynthesis;burning gas results in the production ofcarbon dioxide – increased amounts ofcarbon dioxide increase the rate ofphotosynthesis.

Total 9 marks

4 (a) (i) 1 mark for each of the following ideas:increasing light intensity increases the rateof photosynthesis;until some other factor limits the rate ofphotosynthesis;

(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) 1 mark for each of the following:a y-axis scale from 0–120 arbitrary unitsfilling graph paper vertically and an x-axisscale from 0–1.5% carbon dioxideconcentration filling graph paperhorizontally;all points correctly plotted with a line of bestfit drawn.

(b) 1 mark for each of the following ideas:increasing the concentration of carbondioxide increases the rate of photosynthesis;until some other factor limits the rate ofphotosynthesis.

(c) 1 mark each for:light intensity;temperature.

(d) 1 mark for each of two of the followingideas:the temperature is naturally higher insidethe greenhouse;the temperature inside can be raisedartificially;the carbon dioxide content of the air insidecan be raised artificially;controlling pests is easier.

Total 8 marks

6 (a) 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 becontaminated with toxins;less detrimental effect on environment eg.pesticides kill many organisms which arenot pests or fertilisers may causeeutrophication or production of fertilisers /pesticides uses valuable energy resources.disadvantages:yields often lower;often more expensive.

Total 9 marks

Further questions on Plants as organisms pages 211–12


7 (a) (i) 1 mark for carbon dioxide;(ii) 1 mark for oxygen.

(b) (i) 1 mark for xylem;(ii) 1 mark for phloem.

(c) 1 mark for the idea that it provides energy /light energy converted to chemical energy.

(d) 1 mark each for three of the followingideas:starch insoluble/sugars soluble or in solution;starch does not exert osmotic effect (or a lotof sugar would tend to draw water into thecell);starch ‘metabolically inert’ / does not reacteasily with other substances in the cell;starch (insoluble) takes up less space in thecell.

Total 8 marks

8 (a) 1 mark for each letter, in the order of thedescriptions 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 around6.00 p.m. for day X / sunnier on day Y;short daylight on day X / dark later on dayY.

(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

� Plant transport9 (a) (i) 1 mark for transpiration;

(ii) 1 mark for stomata;(iii) 1 mark for each of the following ideas:

movement of water used to transport;mineral salts;from roots to leaves.

(b) 1 mark for each of the following ideas:(i) increase rate at which bubble moves

towards the plant;(ii) decrease rate at which bubble moves

towards the plant;(iii) move bubble away from the plant.

(c) 1 mark for each of the following ideas:reduced surface area so reducedtranspiration rate;protection from browsing animals.

Total 10 marks

10(a) 1 mark for photosynthesis.(b) 1 mark for each of the following ideas:

by osmosis;through the partially-permeable membraneof the root hair;concentration of water molecules higher insoil than in root hair cell;water molecules move along their diffusiongradient.

(c) 1 mark for each of the following ideas:transpiration exerts a pull;on the water in the xylem;water molecules are cohesive so thecolumn of water is pulled up the xylem.

Total 8 marks

11(a) 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 effecton the response;

(b) 1 mark for each of the following ideas:increased concentration of auxin / hormoneon shaded side of stem;results in increased growth of cells onshaded side;resulting in curvature towards light.

(c) 1 mark for each of the following ideas:plants grow towards maximum light;which they need for photosynthesis.

Total 8 marks

pages 213–14 Further questions on Plants as organisms


12(a) 1 mark for 6.0 mm(b) 1 mark for day 6.(c) 1 mark each for:

20 mm;26 mm;40 mm;60 mm;

(d) 1 mark for each of the following:a y-axis scale from 0–60mm filling graphpaper vertically;an x-axis scale from 0–8 days filling graphpaper horizontally;all points correctly plotted;line of best fit drawn.

Total 10 marks

Further questions on Plants as organisms page 214


� Inheritance1 (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 followingideas: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 ofnucleotide bases;three bases code for one amino acid;if the sequence of bases is changed thewrong amino acid is assembled into theprotein 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, spindleformed;chromosomes lie on equator of spindle;chromatids pulled to opposite poles ofspindle;each set of chromatids surrounded by newnuclear membrane;

(ii) 1 mark for each of the following ideas:the number of chromosomes is halvedduring meiosis;in mitosis it is the same;the cells produced by meiosis do notcontain identical genetic information;cells produced by mitosis are geneticallyidentical;

(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 ratherthan 23;resulting in an egg with 24 chromosomesrather than 23;egg was fertilised by a sperm with23 chromosomes resulting in a zygote with47 chromosomes.

Total 20 marks

3 (a) 1 mark for each correct row:Hh;H h H h;HH hh Hh;normal, sickle, normal and sickle.

(b) 1 mark for each of the following ideas:no possibility of them having children thathave the sickle condition;since neither Joan nor Eric has the sickleallele.

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 twoequal halves;an egg with 24 chromosomes (one extra) isfertilised by a sperm with 23.

(b) (i) 1 mark for each row on the genetic diagramparents 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 donot appear until middle age, the person mayhave become a parent before symptomsappear.

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 thephenotype (rather than two for a recessiveallele).

Total 5 marks

6 1 mark for correct genotypes of parents andgametes: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� Dd;B� dd;If A were DD then there would be no non-affected offspring, so A must be Dd.

(b) 1 mark for each of the following ideas:If the disease was caused by a recessiveallele then:A could have two recessive alleles (dd);B could be a carrier (Dd).

Total 5 marks

pages 276–8 Further questions on Variation, inheritance and evolution


8 (a) (i) 1 mark for from the udder;(ii) 1 mark for the idea to make sure that the

new cell contained only new DNA (ie. notfrom the original cell) / zygote must bediploid to develop (so cannot have threesets of chromosomes);

(iii) 1 mark for sheep A.(b) 1 mark for the idea that the egg is normally

fertilised by a sperm from the male sheep /ram.

(c) 1 mark each for the following ideas:that people understand the work ofscientists;people can then see if the advances inscience are important in their own work /occupation.

(d) 1 mark for the idea that people can getanimals with desirable chacteristics (morequickly than with conventional breeding).

Total 8 marks

9 (a) 1 mark for idea that it is one that can beinherited / passed on through the genes / isdue to a gene mutation.

(b) 1 mark for idea that passage for air to (andfrom) the lungs / bronchioles is blocked orrestricted / air cannot reach air sacs /prevents gas exchange / prevents removal ofcarbon dioxide.

(c) 1 mark for the idea that bacteria are killed /destroyed / growth (of bacteria) is inhibited.

(d) 1 mark for each of the following:(i) Nn;(ii) Nn;(iii) nn;(iv) NN or Nn. (2 marks)

(e) 1 mark for one correct answer. (Note:There are many possible answers and thesecannot all be listed here.) The likelyanswers depend on what is given in thesyllabus / specification, eg. Huntington’schorea / disease; haemophilia; sickle celldisease; muscular dystrophy, etc.

Total 9 marks

� Evolution10(a) 1 mark for a suggestion related to food

shortages or fear of prison eg. there werefood shortages so they wanted to believehim.

(b) 1 mark for DNA / genes are not changed;1 mark for environmental changes are notinherited.

(c) 1 mark for choose plants with the largestfruit;1 mark for breed;1 mark for select largest offspring;1 mark for repeat over several generations.(maximum of 3 marks if ideas are not wellexpressed)

Total 7 marks

11(a) 1 mark for genes are on the chromosomes;1 mark for chromosomes / genes are copied(before cell division).

(b) 1 mark each for any three of the followingideas:interferes with nature / lack of choice;unknown side effects on humans;further selective breeding is more difficult;reduced number of alleles in population /they are all genetically identical.

Total 5 marks

12 1 mark for each correct word used in thefollowing order:gene; restriction; plasmid; ligase; DNA;fermenter; diabetes.

Total 7 marks

13(a) 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

Further questions on Variation, inheritance and evolution pages 278–80


14(a) (i) 1 mark for each of two of the followingideas: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 followingideas: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 ofideas:grey squirrels can out-compete red squirrelsfor food;so will not starve or can reproduce moresuccessfully;grey squirrels can live in a greater variety ofwoodlands;so have a greater chance of surviving if onetype of habitat is destroyed;grey squirrels have a higher reproductiverate 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 thinnerbeaks;competition for small insects as food;birds with thinner beaks could eat smallerinsects 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 numbersbecause less soot was deposited on trees;therefore the moths were less conspicuousto birds;dark coloured moths decreased in numbers;because they became more conspicuous tobirds;

(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

pages 280–81 Further questions on Variation, inheritance and evolution


� Adaptation and competition1 (a) 1 mark each for two differences eg.:

trees in wood taller;trees in wood are narrower;trees in wood have fewer leaves / brancheshigher up.

(b) 1 mark each for:light;water;mineral salts.

Total 5 marks

2 (a) 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.

(b) no sweating reduces water loss;can go longer without drinking / not muchwater in desert.

(c) weight spread out over large area;less likely to sink into sand.

(d) acts as an insulator;so that they stay warm at night.

Total 8 marks

3 (a) 1 mark each for:(i) day 2;(ii) day 4;(iii) day 3.

(b) 1 mark each for:food availability;oxygen availability;amount of poisonous waste products.

(c) (i) 1 mark for all dead;(ii) 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 bytranspiration.

(c) 1 mark for the idea that leaves are reducedto spines, so the stem takes over the role ofphotosynthesis.

(d) 1 mark for the idea that in the hottest partof the day / there will be few insects aroundfor pollination.

Total 6 marks

5 (a) (i) 1 mark for 10 years;(ii) 1 mark for 1986.

(b) (i) 1 mark for the idea that the lynx populationis also increasing;

(ii) 1 mark for the idea that there were moreprey (hares) for the lynx to feed on.

(c) 1 mark each for three of the followingideas: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) affectinghare 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 becausethere are fewer hares / less food to feed on /more competition from foxes for food.

Total 10 marks

Further questions on Living things and their environment pages 340–41


� Energy and nutrient transfer6 (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 increasebecause the pike are no longer eating them;

(ii) 1 mark for each of the following ideas:decrease because herons would eat more ofthem;because there would be fewer pike for theherons to feed on.

(c) 1 mark for each of the following ideas:decrease numbers of primary consumers;because carp would compete with them forfood;decrease numbers of secondary consumers;because they would have fewer primaryconsumers 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 grouseto 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 owlin ascending order;layers – widest is oak followed bycaterpillar, vole, and owl in decreasingwidths;

(iv) 1 mark for the idea that it is lost as heatfrom respiration.

(b) 1 mark for each of the following ideas:pollution eg. increased sulfur dioxide;could kill off some of the lichens or causeleaf 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

10(a) 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.

(b) (i) 1 mark for each of the following ideas:produce more food;from same amount of land;

(ii) 1 mark for good example eg.fish farming or greenhouse or hydrophonicsor battery chickens.1 mark for a good explanation eg.avoids the need to go out and catch the fish.

(iii) 1 mark for idea of production costs arehigher.1 mark for good explanation eg. moremanual labour.

(c) (i) 1 mark for idea of less pests eating the food.(ii) 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 � level D andsecondary consumer � level C)tertiary consumers receive a total of 120units of energy from secondary consumersand lose 24 units of energy to decomposers;so energy transferred to environment is(120 � 24) � 96, therefore % energytransferred � (96 � 100) � 120 � 80%.

(ii) 1 mark for two of the following ideas:(mammals and birds are) more active somore respiration generating heat;(mammals and birds have) constant bodytemperature;(mammals and birds) lose heat faster to theenvironment, so faster rate of respiration toreplace it.

Total 6 marks

12(a) 1 mark for 12 � 80 � 100;1 mark for 15.

(b) 1 mark for each of two of the following:biomass lost in faeces / waste;biomass used in respiration;biomass used in growth / repair.

(c) 1 mark for less biomass used in respiration;1 mark for as less movement;1 mark for less energy needed to maintainbody temperature.

Total 7 marks

pages 341–3 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

� Humans and the environment14(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 duringphotosynthesis;combustion of trees releases carbon dioxide.

(iii) 1 mark for each of the following ideas:increase in carbon dioxide may add togreenhouse effect;resulting in global warming;less transpiration may lead to drier climates;increased leaching of mineral salts fromsoil;increased soil erosion since fewer tree rootsto bind soil.

(c) 1 mark for each of two of the followingideas:set-aside provides wider range of habitats /food plants / breeding sites;sites of special scientific interest / naturereserves – havens for threatened species;captive breeding programmes – release intowild;reduce use of herbicides – rare species lesslikely to be killed;reduce use of insecticides – effect on foodchains;reduce use of fertilisers – reference toeutrophication effects;conserve hedgerows, provides wide range ofhabitats / food plants / breeding sites.

Total 13 marks

15(a) 1 mark each for two of the following ideas:the ash contains nutrients;eg. nitrate/phosphate, etc.;acts as a fertiliser / improves plant growth.

(b) 1 mark for each of the following ideas:cattle produce methane;in digestive system / stomach.

(c) 1 mark each for two of the following ideas:during growth, trees take in nitrate / increasebecause nitrate no longer taken up;increased leaching / washing out of nitratefrom the soil (and so into stream);decomposition of trees or other material leftafter 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 ismaintained;

(ii) 1 mark for idea of fishing quotas or banfishing.

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 influencegreenhouse effect;water vapour has the greatest greenhouseeffect.

(b) 1 mark for each of the following ideas:at stage 1 radiation reaches the Earth andsome is reflected and some is used inphotosynthesis;at stage 2 radiation escapes but some istrapped.

(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 livingorganisms.

(d) 1 mark for each of the following ideas:ultra-violet light enters;and can cause skin cancer.

Total 10 marks

Further questions on Living things and their environment pages 344–5


18(a) 1 mark for (for crops) to make protein.1 mark for growth / increase yield.

(b) 1 mark each for any six of the following:rapid / more growth of (water) plants;increased competition for light / no light toplants below;death of plants / algae;food for microbes / dead plants decayed bymicrobes;microbes increase in number;oxygen used (by microbes);in respiration (of microbes);lack of oxygen kills fish / fish suffocate.

(c) 1 mark for correct use of at least twoscientific 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) putrefyingbacteria or putrefying bacteria (produceammonia);ammonia is turned to nitrate;(ammonia is used by) nitrifying bacteriaor nitrifying bacteria (produce nitrate).

Total 12 marks

page 345 Further questions on Living things and their environment


� Biotechnology1 (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 (notwanted for yoghurt-making process).

(b) 1 mark each for two of the following ideas:(the bacteria) ferment/convert lactose in themilk 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 forenzyme activity;fermentation proceeds more quickly.

(d) 1 mark each for the following ideas:reduces/slows down further bacterialactivity/fermentation;(further activity) might change flavour/altertexture etc. of yoghurt.

Total 8 marks

2 (a) 1 mark for stirring / mixing contents.(b) 1 mark for one of the following:

nutrient(s) (solution) / named nutrient;microbes (culture) / micro-organisms.

(c) 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 cellreactions).

(d) provide oxygen (for respiration).Total 5 marks

3 (a) (i) Plot graph with time on horizontal axis andpH on vertical axis (given in question) – sofind suitable scale using most of graphpaper and make sure each point is plottedaccurately and line drawn to connectpoints.

(ii) 1 mark for a pH of 5.4 (or as read off fromthe plotted graph).

(b) (i) 1 mark for each of the following ideas:bacteria / Lactobacillus / Streptococcusferment lactose / milk sugar;to lactic acid;so culture / milk becomes more acid /pH falls.

(ii) 1 mark for idea that acid / lower pH causesproteins / 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

4 (a) 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.).

(b) 1 mark for methane.(c) 1 mark for each of the following ideas:

keeps air out; keeps inside anaerobic;stronger container (withstands pressure ofgas building up inside).

Total 6 marks

Further questions on Biotechnology and Behaviour pages 371


� Behaviour1 (a) (i) 1 mark for each of the following:

lines both labelled;one scale covers half the grid and is linear;axes correct with day as independentvariable and average number of wrong turnsas the dependent variable;2 marks for points plotted accurately.

(ii) 1 mark for idea that rats A made fewerwrong turns the more times they used themaze;

(iii) 1 mark for each of the following:rats A learned to make fewer wrong turns;as a result of being rewarded with food.

(b) 1 mark for each example (to a maximum oftwo marks) such as sheep dogs herdingsheep or circus animals doing tricks.

Total 10 marks

2 (a) 2 marks for any two of the following ideas:Behaviour that is : modified by experience;

: not inherited;: differs between species;: quickly adapted to newcircumstances.

(b) (i) 1 mark for each of the following ideas (to amaximum of three marks):there was little change in the mean heartrates of the students;the mean heart rates of the ex-sailorsincreased with the number of bell rings perminute;the mean heart rates of the ex-sailorsreached a peak at 100 bell rings per minute;over 100 bell rings per minute, the meanheart rates of the ex-sailors decreased.

(ii) 1 mark for each of the following ideas:the ex-sailors’ mean heart rates wouldincrease when experiencing the sound ofguns and bombs;at first the neutral stimulus of a bell ringingmay not increase the ex-sailors’ heart rates;after a period of training / experience inaction, ringing the bell alone at 100 timesper minute increases the ex-sailors’ heartrates;the ex-sailors have learned to associate thesound of the bell ringing at 100 times perminute with danger;the new stimulus (sound of the bell ringingat 100 times per minute) has replaced theoriginal stimulus.

Total 10 marks

3 (a) 1 mark for each of the following ideas:at first ash from burnt trees providednutrients for crop growth;with time nutrients were used up so cropyield fell.

(b) 1 mark for each from two of the followingideas:use of fertilisers increase crop yield;use of pesticides increase crop yield;crops have been selectively bred for highyield.

Total 4 marks

page 372 Further questions on Biotechnology and Behaviour

Documents

Biology For You Intro and Answers to Further Questions