Table Of Content

AQA Biology 2nd Edition A LEVEL OXFORD OXFORD VNIVBRSITY PRESS Great Clarendon Street, Oxford, OX2 6DP. United Kingdom Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark ofOxford University Press in the UK and in certain other countries © Glenn and Susan Toole 2015 The moral rights of the authors have been asserted First published in 2015 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing ofOxford University Press, or as expressly permitted by law, by licence or under tem1s agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above. You must not circulate this work in any other form and you must impose this same condition on any acquirer British Library Cataloguing in Publication Data Data available 978·0·19·835177·1 10 9 8 7 6 5 Paper used in the production of this book is a natural, recyclable product made from wood grown in sustainable forests. The manufacturing process conforms to the environmental regulations of the country oforigin. Printed in China by Golden Cup Printing Co Ltd Message from AQA This textbook has been approved by AOA for use with our qualification. This means that we have checked that it broadly covers the specification and we are satisfied with the overall quality. Full details of our approval process can be found on our website. We approve textbooks because we know how important it is for teachers and students to have the right resources to support their teaching and learning. However, the publisher is ultimately responsible for the editorial control and quality of this book. Please note that when teaching the AOA AS orA-Level Biology course, you must refer to AOA's specification as your definitive source ofinformation. While this book has been written to match the specification, it cannot provide complete coverage of every aspect of the course. A wide range of other useful resources can be found on the relevant subject pages of our website: www.aqa.org.uk. This book has been writcen co support students studying for AQA A Level Biology. The sections covered are shown in the contents list, which also shows you the page numbers for the main topics within each section. There is also an index at the back to help you find what you are looking for. If you are studying for AS Biology, you will only need to know the content in the blue box for the AS exams. E r ca Year 1 content Yea r 2 content >< Cl) 1 Biological molecules 5 Energy transfers in and (/) 2 Cells between organisms ~ 3 Organisms exchange 6 Organisms respond to changes substances with their in their internal and external environment environment E 4 Genetic information, variation, 7 Genetics, populations, evolution, ca >< and relationships between and ecosystems Cl) organisms 8 The control of gene expression Cl) > ""' -Cl) -' ~ ALevel exams will cover content from Year 1 and Year 2 and will be at a higher demand. You will also carry out practical activities throughout your course. There are twelve required practicals: six from the AS and six A-Level. How to use this book viii Kerboodle xi Section 1 4 Transport across cell membranes 84 Biological molecules 2 4.1 Structure of the cell surface membrane 84 4.2 Diffusion 87 1 Biological molecules 4 4.3 Osmosis 89 1.1 Introduction to biological molecules 4 4.4 Active transport 93 1.2 Carbohydrates and monosacharides 8 4.5 Co·transport and absorption of glucose 1.3 Carbohydrates - disaccharides and in the ileum 95 polysaccharides 10 Practice questions 99 1.4 Starch, glycogen and cellulose 13 1.5 Lipids 16 5 Cell recognition and the immune system 102 1.6 Proteins 19 5.1 Defence mechanisms 102 1.7 Enzyme action 23 5.2 Phagocytosis 104 1.8 Factors affecting enzyme action 26 5.3 T Lymphocytes and cell mediated 1.9 Enzyme inhibition 32 immunity 106 Practice questions 34 5.4 B lymphocytes and humoral immunity 109 5.5 Antibodies 111 2 Nucleic acids 36 5.6 Vaccination 115 2.1 Structure of RNA and DNA 36 5.7 Human immunodeficiency virus (HIV) 119 2.2 DNA replication 42 Practice questions 122 2.3 Energy and ATP 46 Section 2 summary 124 2.4 Water and its functions so Section 2 practice questions 126 Practice questions Section 1 summary 52 Section 3 Section 1 practice questions 54 Organisms exchange substances with their environment 128 Section 2 Cells 56 6 Exchange 130 6.1 Exchange between organisms and 3 Cell structure 58 their environment 130 3.1 Methods of studying cells 58 6.2 Gas exchange in single-celled 3.2 The electron microscope 61 organisms and insects 133 3.3 Microscopic measurements and 6.3 Gas exchange in fish 135 calculations 64 6.4 Gas exchange in the leaf of a plant 137 3.4 Eukaryotic cell structure 67 6.5 Limiting water loss 139 3.5 Cell specialisation and organisation 73 6.6 Structure of the human 3.6 Prokaryotic cells and viruses 75 gas-exchange system 142 3.7 Mitosis 77 6.7 The mechanism of breathing 144 3.8 The cell cycle 80 6.8 Exchange of gases in the lungs 146 Practice questions 82 6.9 Enzymes and digestion 151 6.10 Absorption ofthe products of digestion 155 Practice questions 158 • 7 Mass transport 161 Section 4 summary 260 7.1 Haemoglobin 161 Section 4 practice questions 262 7.2 Transport of oxygen by haemoglobin 163 7.3 Circulatory system of a mammal 168 Section 5 7.4 The structure of the heart 170 Energy transfer in and 7.5 The cardiac cycle 174 between organisms 266 7.6 Blood vessels and their functions 178 11 Photosynthesis 268 7.7 Transport of water in the xylem 183 11.1 Overview of photosynthesis 268 7.8 Transport of organic molecules in 11.2 The light-dependent reaction 271 the phloem 188 11.3 The light-independent reaction 275 7.9 Investigating transport in plants 191 Practice questions 281 Practice questions 194 Section 3 summary 196 12 Respiration 283 Section 3 practice questions 198 12.1 Glycolysis 283 12.2 Link reaction and Krebs cycle 286 Section 4 12 3 Oxidative phosphorylation 289 12.4 Anaerobic respiration 293 Genetic information, variation and Practice questions 296 relationships between organisms 200 8 DNA, genes and protein synthesis 202 13 Energy and ecosystems 298 8.1 Genes and the triplet code 202 13.1 Food chains and energy transfer 298 8.2 ONA and chromosomes 205 13.2 Energy transfer and productivity 300 8.3 The structure of ribonucleic acid 208 13.3 Nutrient cycles 306 8.4 Protein synthesis - transcription 13.4 Use of natural and artificial fertilisers 311 and splicing 211 13.5 Environmental issues concerning 8.5 Protein synthesis - translation 213 use of nitrogen-containing fertilisers 313 Practice questions 217 Practice questions 315 9 Genetic diversity 220 Section 5 summary 318 9.1 Mutations 220 Section 5 practice questions 320 9.2 Meiosis and genetic variation 224 Section 6 9.3 Genetic diversity and adaptation 229 9.4 Types ofselection 231 Organisms respond to changes Practice questions 235 in their environments 324 10 Biodiversity 237 14 Response to stimuli 326 10.1 Species and taxonomy 237 14.1 Survival and response 326 10.2 Diversity within a community 243 14.2 Plant growth factors 328 10.3 Species diversity and human activity 246 14.3 A reflex arc 334 10.4 Investigating diversity 249 14.4 Receptors 337 10.5 Quantitative investigations ofvariation 253 14.5 Control of heart rate 340 Practice questions 257 Practice questions 344 • 15 Nervous coordination and muscles 346 18 Populations and evolution 448 15.1 Neurones and nervous coordination 346 18.1 Population genetics 448 15.2 The nerve impulse 350 18.2 Variation in phenotype 451 15.3 Passage of an action potential 354 18.3 Natural selection 453 15.4 Speed of the nerve impulse 357 18.4 Effects of different forms of 15.5 Structure and function of synapses 360 selection on evolution 456 15.6 Transmission across a synapse 364 18.5 Isolation and speciation 460 15.7 Structure of skeletal muscle 367 Practice questions 464 15.8 Contraction of skeletal muscle 371 19 Populations in ecosystems 466 Practice questions 376 19.1 Populations in ecosystems 466 16 Homeostasis 378 19.2 Variation in population size 468 16.1 Principles of homeostasis 378 19.3 Competition 474 16.2 Feedback mechanisms 383 19.4 Predation 478 16.3 Hormones and the regulation of 19.5 Investigating populations 481 blood glucose concentration 386 19.6 Succession 484 16.4 Diabetes and its control 391 19.7 Conservation of habitats 488 16.5 Control of blood water potential - Practice questions 490 structure of the nephron 394 Section 7 summary 492 16.6 Role of the nephron in osmoregulation 399 Section 7 practice questions 494 16.7 The role of hormones in osmoregulation 404 Practice questions 407 Section 8 Section 6 summary 410 The control of gene expression 498 Section 6 practice questions 412 20 Genet' p ·e on 500 Section 7 20.1 Gene mutations 500 20.2 Stem cells and totipotency 504 Genetics, populations, evolution, 20.3 Regu lation of transcription and ecosystems 416 and translation 510 17 Inherited change 418 20.4 Epigenetic control of gene expression 513 17.1 Studying inheritance 418 20.5 Gene expression and cancer 519 17.2 Monohybrid inheritance 421 20.6 Genome projects 525 17.3 Probability and genetic crosses 424 Practice questions 528 17.4 Dihybrid inheritance 426 21 Recomb'nan ONA t chnol y 530 17.5 Codominance and multiple alleles 429 17.6 Sex-linkage 433 21.1 Producing DNA fragments 530 17.7 Autosomal linkage 437 21.2 In vivo gene cloning - the use of vectors 535 17.8 Epistasis 440 17.9 The chi-squared (x2) test 443 21.3 In vitro gene cloning - the polymerase chain reaction 5"40 Practice questions 446 • 21.4 Locating genes, genetic screening, and counselling 545 21.5 Genetic fingerprinting 550 Practice questions 556 Section 558 Section 8 practice questions 560 Section 9 Skills in A level Biology 564 Chapter 22 Mathematical skills (including statistics) 564 Chapter 23 Practical skills 581 AS additional practice questions 589 A level additional practice questions 597 Synoptic questions 603 Answers 607 Practical skills answers 651 Glossary 655 Index 665 Acknowledgements and Imprint 675 • Learning objectives This book contains many different features. Each feature is designed to foster and stimulate your interest in Biology, as well as supponing and ' At the beginning of each developing the skills you will need for your examinations. topic, there is a list of learning objectives. Terms that you will need to be able to define and understand are ' These are matched to the shown in bold type within the text. specification and allow you Where terms are not explained within the same topic, they are to monitor your progress. highlighted in bold orange text. You can look these words up in ' A specification reference is the glossary. also included. Specification reference: 3.1.1 Synoptic link These features contain important and interesting applications of biology in order to emphasise how scientists and engineers These highlight how the sections have used their scientific knowledge and understanding to develop relate to each other. Linking new applications and technologies. Theree are. a lso application features to different areas of biology together develop your maths skills, with the icon and to develop your practical O· becomes increasingly important, skills, with the icon and you will need to be able to do this. There are also links to the mathematical skills on the specification. More detail can be Extension features found in the maths section. These features contain material that is beyond the specification designed to stretch and provide you with a broader knowledge and understanding and lead the way into the types of thinking and areas you might study in further education. As such, neither the detail nor the depth of questioning will be required for the examinations. But this book is about more than getting through the examinations. 1 Extension and application features have questions that link the material with concepts that are covered in the specification. Answers can be found in the answers section at the back of the book. Study tips Study tips contain prompts to help you with your revision. Summary questions 1 These are short questions that test your understanding of the Hint topic and allow you to apply the knowledge and skills you have aquired. The questions are ramped in order of difficulty. Hint features give other fi information or ways of thinking 2 Questions that will test and develop your mathematical about a concept to support your and practical skills are labelled with the mathematical symbol understanding. [fi) and the practical symbol [O J. •