OXFORD IB DIplOm a pROgRam m e
2 0 1 4 ED I TI O N
BIOLO GY
C O U R S E C O M PA N I O N
Andrew Allott
David Mindorf
, PHOTO LIBRARY; p101-102: OUP; p110: SPL; p116: Author Image; p122:
3
Great Clarendon Street, Oxford, OX2 6DP, United Kingdom
Tony Rusecki / Alamy; p123a: OUP; p123b: Glenn Tattersall; p124a:
MATTHEW OLDFIELD/SCIENCE PHOTO LIBRARY; p124b: Author Image;
p152: OUP; p126a: OUP; p126b: Petrov Andrey/Shutterstock; p130a: OUP;
p130b: OUP; p130c: Andrew Allott; p131c: Andrew Allott; p132a: OUP; p133:
Oxford University Press is a department of the University of Oxford. It William Allott; p134: OUP; p141: OUP; p143a: Jax.org; p143b: Jax.org; p143c:
furthers the Universitys objective of excellence in research, scholarship, Jax.org; p144: www.ncbi.nlm.nih.gov/pubmed; p146a: Eye of Science/SPL;
and education by publishing worldwide. Oxford is a registered trade mark p146b: Eye of Science/SPL; p148: MAURO FERMARIELLO/SCIENCE PHOTO
of Oxford University Press in the UK and in certain other countries LIBRARY; p150a: M .Wurtz/Biozentrum/University o fBasel/SPL; p150b:
Oxford University Press 2014 Kwangshin Kim/SPL; p151: www.ncbi.nlm.nih.gov; p152: Dr. Oscar Lee
The moral rights of the authors have been asserted Miller, Jr of the University of Virginia; p155a: OUP; p155b: Andrew Allot;
p156: OUP; p158a: DEPT. OF CLINICAL CYTOGENETICS, ADDENBROOKES
First published in 2014 HOSPITAL/SCIENCE PHOTO LIBRARY; p158b: Tomasz Markowski/
All rights reserved. No part of this publication may be reproduced, stored Dreamstime; p159: L. WILLATT, EAST ANGLIAN REGIONAL GENETICS
in a retrieval system, or transmitted, in any form or by any means, without SERVICE/SCIENCE PHOTO LIBRARY; p160-161b: OUP; p162a: Andrew Allot;
the prior permission in writing of Oxford University Press, or as expressly p164a,b,c,d: Andrew Allot; p165a,b,c,d: Andrew Allot; p166a: OUP; p166b:
permitted by law, by licence or under terms agreed with the appropriate OUP; p166c: OUP; p169: OUP; p171a: OUP; p171b: OUP; p172: William Allott;
reprographics rights organization. Enquiries concerning reproduction p176: Enrico Coen; p177-184a: OUP; p184b: OUP; p186: RIA NOVOSTI/
outside the scope of the above should be sent to the Rights Department, SCIENCE PHOTO LIBRARY; p188: VOLKER STEGER/SCIENCE PHOTO
Oxford University Press, at the address above. LIBRARY; p189: OUP; p190a: Andrew Allot; p190b: DAVID PARKER/SCIENCE
PHOTO LIBRARY; p190c-196c: OUP; p197: WALLY EBERHART, VISUALS
You must not circulate this work in any other form and you must impose
UNLIMITED /SCIENCE PHOTO LIBRARY; p198a: GERARD PEAUCELLIER, ISM
this same condition on any acquirer
/SCIENCE PHOTO LIBRARY; p198b: GERARD PEAUCELLIER, ISM /SCIENCE
British Library Cataloguing in Publication Data PHOTO LIBRARY; p198c: Author Image; p199: PHILIPPE PLAILLY/SCIENCE
Data available PHOTO LIBRARY; p201: OUP; p202: Parinya Hirunthitima/Shutterstock;
978-0-19-839211-8 p203a: OUP; p203b: OUP; p203c: ERIC GRAVE/SCIENCE PHOTO LIBRARY;
p203d: OUP; p204a,b,c,d: Andrew Allot; p205a: Author Image; p205b:
1 3 5 7 9 10 8 6 4 2 CreativeNature.nl/Shutterstock; p205c: Author Image; p206: OUP; p207:
Paper used in the production of this book is a natural, recyclable product OUP; p207b: Author Image; p209: Author Image; p210: OUP; p211: OUP;
made from wood grown in sustainable forests. The manufacturing process p212a: OUP; p212b: Andrew Allott; p214: Andrew Allott; p215a: OUP; p215b:
conforms to the environmental regulations of the country of origin. Andrew Allott; p215c: Andrew Allott; p215d: Rich Lindie/Shutterstock;
Printed in Malaysia p215e: OUP; p217a: OUP; p217b: Andrew Allott; p217d: OUP; p221:
Giorgiogp2/Wikipedia; p223a: Andrew Allott; p223b: Andrew Allott; p224:
Acknowledgements OUP; p225a: OUP; p225b: Andrew Allott; p225c: Andrew Allott; p228-242b:
The publishers would like to thank the following for permissions to use OUP; p243: Erik Lam/Shutterstock; p244: Sinclair Stammers/SPL; p246a:
their photographs: Wikipedia; p246b: Daiju AZUMA; p246c: Wikipedia; p246d: Shutterstock;
Cover image: Paul Souders/Corbis; p1: Sulston & Horvitz; p2: DR YORGOS p248a: Andrew Allott; p248b Andrew Allott; p250a: OUP; p250b: OUP;
NIKAS/SCIENCE PHOTO LIBRARY; p3a: DR.JEREMY BURGESS/SCIENCE p251a: OUP; p251b: OUP; p251c: OUP; p251d: OUP; p251e: PETER
PHOTO LIBRARY; p3b: Shutterstock; p6: Ferran Garcia-Pichel, Max Planck CHADWICK/SCIENCE PHOTO LIBRARY; p253: OUP; p259: Author Image;
Institute of Marine Biology, Bermen Germany; p7a: Prof. P.Motta & T. p261: OUP; p262a: OUP; p262b: OUP; p264: Andrew Allot; p265: Kipling
Naguro/ SPL; p7b: Andrew Allot; p7c: Andrew Allot; p7d: MICHAEL ABBEY/ Brock/Shutterstock; p270a: Author Image; p270b: Author Image; p272: OUP;
SCIENCE PHOTO LIBRARY; p8a: Carolina Biological Supply Co/Visuals p276a: OUP; p276b: BOB GIBBONS/SCIENCE PHOTO LIBRARY; p279: BSIP
Unlimited, Inc.; p8b: ASTRID & HANNS-FRIEDER MICHLER/SCIENCE PHOTO VEM/SCIENCE PHOTO LIBRARY; p281: Dennis Kunkel/Photolibrary; p282:
LIBRARY; p9: MICHAEL ABBEY/SCIENCE PHOTO LIBRARY; p10a: DR. PETER Author Image; p283a: Andrew Allot; p283b: OUP; p286: Author Image; p290:
SIVER, VISUALS UNLIMITED /SCIENCE PHOTO LIBRARY; p10b: Sulston & Public Domain/Wikipedia; p292a: OUP; p292b: OUP; p294a: OUP; p294b:
Horvitz; p12: JAMES CAVALLINI/SCIENCE PHOTO LIBRARY; p14a: CHRIS BIOPHOTO ASSOCIATES/SCIENCE PHOTO LIBRARY; p298: Andrew Allot;
BARRY/VISUALS UNLIMITED, INC. /SCIENCE PHOTO LIBRARY; p14b: SIMON p299: OUP; p302: OUP; p303a: OUP; p303b: Andrew Allot; p304a: OUP;
FRASER/DEPARTMENT OF HAEMATOLOGY, RVI, NEWCASTLE/SCIENCE p304b: OUP; p305: JAMES CAVALLINI/SCIENCE PHOTO LIBRARY; p306: ST
PHOTO LIBRARY; p16a: TEK IMAGE/SCIENCE PHOTO LIBRARY; p17: MARYS HOSPITAL MEDICAL SCHOOL/SCIENCE PHOTO LIBRARY; p307:
LAWRENCE BERKELEY NATIONAL LABORATORY/ SCIENCE PHOTO LIBRARY; OUP; p308: Wikipedia; p309: OUP; p315: OUP; p317: DU CANE MEDICAL
p19: A B Dowsett/SPL; p20a: Eye of Science/SPL; p20b: CNRI/SCIENCE PHOTO IMAGING LTD/SCIENCE PHOTO LIBRARY; p318: OUP; p320a: OUP; p320b:
LIBRARY; p21a: BIOPHOTO ASSOCIATES/SCIENCE PHOTO LIBRARY; p21b: THOMAS DEERINCK, NCMIR/SCIENCE PHOTO LIBRARY; p323: OUP; p325:
MICROSCAPE/SCIENCE PHOTO LIBRARY; p22a: BIOPHOTO ASSOCIATES/ BSIP VEM/SCIENCE PHOTO LIBRARY; p327: OUP; p328a: SCIENCE VU,
SCIENCE PHOTO LIBRARY; p22b: DR GOPAL MURTI/SCIENCE PHOTO VISUALS UNLIMITED /SCIENCE PHOTO LIBRARY; p328b: OUP; p330: J.
LIBRARY; p22c: DR GOPAL MURTI/SCIENCE PHOTO LIBRARY; p22d: ZBAEREN/EURELIOS/SCIENCE PHOTO LIBRARY; p331: OUP; p332: OAK
MICROSCAPE/SCIENCE PHOTO LIBRARY; p22e: DR KARI LOUNATMAA/ RIDGE NATIONAL LABORATORY/US DEPARTMENT OF ENERGY/SCIENCE
SCIENCE PHOTO LIBRARY; p22f: MICROSCAPE/SCIENCE PHOTO LIBRARY; PHOTO LIBRARY; p333: OUP; p334: POWER AND SYRED/SCIENCE PHOTO
p23a: DON W. FAWCETT/SCIENCE PHOTO LIBRARY; p23b: DR. GOPAL LIBRARY; p339: CHASSENET/BSIP/SCIENCE PHOTO LIBRARY; p340: Author
MURTI/SCIENCE PHOTO LIBRARY; p23c: Andrew Allot; p24a: STEVE Image; p343: SIMON FRASER/SCIENCE PHOTO LIBRARY; p344: LEE D.
GSCHMEISSNER/SCIENCE PHOTO LIBRARY; p24b: DR.JEREMY BURGESS/ SIMON/SCIENCE PHOTO LIBRARY; p346: SPL; p348: Image of PDB ID 1aoi (K.
SCIENCE PHOTO LIBRARY; p25a: STEVE GSCHMEISSNER/SCIENCE PHOTO Luger, A.W. Mader, R.K. Richmond, D.F. Sargent, T.J. Richmond (1997)
LIBRARY; p25b: DAVID M. PHILLIPS/SCIENCE PHOTO LIBRARY; p25c: STEVE structure of the core particle at 2.8 A resolution Nature 389: 251-260)
GSCHMEISSNER/SCIENCE PHOTO LIBRARY; p27: Author Image; p28: NIBSC/ created with Chimera (UCSF Chimera--a visualization system for exploratory
SCIENCE PHOTO LIBRARY; p29: Author Image; p32: Janaka Dharmasena/ research and analysis. Pettersen EF, Goddard TD, Huang CC, Couch GS,
Shutterstock; p43a: OUP; p43b: Andrew Allot; p44: Herve Conge/SPL; p45: Greenblatt DM, Meng EC, Ferrin TE. J Comput Chem. 2004 Oct;25(13):1605-
David Mayer, Consultant and CSL Liver Surgery, Queen Elizabeth Hospital, 12. ); p349: Public Domain/Wikipedia; p351: SCIENCE PHOTO LIBRARY;
Birmingham; p46a: THOMAS DEERINCK, NCMIR/SCIENCE PHOTO LIBRARY; p352: Andrew Allot; p353: Charvosi/Wikipedia; p357: Axel Bueckert/
p46b: The VRoma Project (www.vroma.org); p48: GEORGETTE DOUWMA/ Shutterstock; p358: PNAS.Org; p359: DR ELENA KISELEVA/SCIENCE PHOTO
SCIENCE PHOTO LIBRARY; p49: DAVID MCCARTHY/SCIENCE PHOTO LIBRARY; p363a: Jmol; p363b: RCSB.org; p367: 1970 American Association
LIBRARY; p51: M.I. Walker/SPL; p53a,b,c,d: STEVE GSCHMEISSNER/SCIENCE for the Advancement of Science. Miller, O. L. et al. Visualization of bacterial
PHOTO LIBRARY; p54a,b: STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY; genes in action. Science 169,392395 (1970). All rights reserved; p368a:
p55a: Dharam M Ramnani; p55b: MANFRED KAGE/SCIENCE PHOTO Nobelprize.org; p368b: POWER AND SYRED/SCIENCE PHOTO LIBRARY;
LIBRARY; p55c: MANFRED KAGE/SCIENCE PHOTO LIBRARY; p57: MOREDUN p368c: SINCLAIR STAMMERS/SCIENCE PHOTO LIBRARY; p370a: Andrew
ANIMAL HEALTH LTD/SCIENCE PHOTO LIBRARY; p58: OUP; p54: Andrew Allot; p373: Shutterstock; p375: RAMON ANDRADE 3DCIENCIA/SCIENCE
Allot; p60: J Herve Conge, ISM/ SPL; p61: OUP; p62: Vasiliy Koval/Shutterstock; PHOTO LIBRARY; p387a: CNRI/SCIENCE PHOTO LIBRARY; p387b: Petrov
p66: LAGUNA DESIGN/SCIENCE PHOTO LIBRARY; p69a-p69b: OUP; p70: Andrey/Shutterstock; p387c: Prof. Kenneth R Miller/ SPL; p387d: Andrew
CLAIRE PAXTON & JACQUI FARROW/SCIENCE PHOTO LIBRARY; p71: DR Allot; p387e: Andrew Allot; p388: Dr. Carmen Manella, Wadsworth
KEITH WHEELER/SCIENCE PHOTO LIBRARY; p72: OUP; p73a: Dr. Elena Center,New York State Department of Health; p390: Prof. Kenneth R Miller/
Kiseleva/SPL; p73b: Dr. Gopal Murti/SPL; p73c: Dr. Elena Kiseleva/SPL; p75a: SPL; p392: Andrew Allot; p398: Andrew Allot; p399: Barrie Juniper; p403:
LAGUNA DESIGN/SCIENCE PHOTO LIBRARY; p75b: LAGUNA DESIGN/ POWER AND SYRED/SCIENCE PHOTO LIBRARY; p404: SINCLAIR STAMMERS/
SCIENCE PHOTO LIBRARY; p75c: LAGUNA DESIGN/SCIENCE PHOTO SCIENCE PHOTO LIBRARY; p405a: Smugmug.Com; p405b: SCIENCE PHOTO
LIBRARY; p79: OUP; p80a: Andrew Allot; p80b-81: OUP; p83a: OUP; p83b: LIBRARY; p406a: POWER AND SYRED/SCIENCE PHOTO LIBRARY; p406b: DR
Giles Bell; p90a: OUP; p90b: www.rcsb.org; p91: www.rcsb.org; p92a: KEITH WHEELER/SCIENCE PHOTO LIBRARY; p410: SIDNEY MOULDS/
Yikrazuul/Wikipedia; p92b: OUP; p95: JAMES KING-HOLMES/SCIENCE SCIENCE PHOTO LIBRARY; p411: DR KEITH WHEELER/SCIENCE PHOTO
Continued on back page.
,Contents
1 Cell Biology 7 Nucleic acids (AHL) Environmental protection 5 75
Introduction to cells 1 D NA structure and Medicine 5 82
Ultrastructure o cells 16 replication 3 43 B ioormatics 5 91
Membrane structure 25 Transcription and gene
Membrane transport 33 expression 355 C Ecology and conservation
The origin o cells 45 Translation 3 62 Species and communities 603
C ell division 51 C ommunities and
8 Metabolism, cell ecosystems 61 3
2 Molecular Biology respiration and Impacts o humans on
Molecules to metabolism 61 photosynthesis (AHL) ecosystems 62 5
Water 68 Metabolism 3 73 C onservation o biodiversity 63 5
C arbohydrates and lipids 73 C ell respiration 3 80 Population ecology 642
Proteins 87 Photosynthesis 3 89 The nitrogen and
E nzymes 96 phosphorous cycles 649
S tructure o D NA and RNA 1 05 9 Plant biology (AHL)
D NA replication, transcription Transport in the xylem D Human physiology
and translation 111 o plants 403 Human nutrition 65 9
C ell respiration 1 22 Transport in the phloem o D igestion 671
Photosynthesis 1 29 plants 41 2 Functions o the liver 678
Growth in plants 42 2 The heart 684
3 Genetics Reproduction in plants 42 9 Hormones and metabolism 694
Genes 1 41 Transport o respiratory
C hromosomes 1 49 10 Genetics and evolution gases 699
Meiosis 1 59 (AHL) Internal Assessment
Inheritance 1 68 Meiosis 43 9 (with thanks to Mark Headlee for
Genetic modication and Inheritance 445 his assistance with this chapter) 708
biotechnology 1 87 Gene pool and speciation 45 5
Index 71 3
4 Ecology 11 Animal physiology (AHL)
S pecies, communities and Antibody production and
ecosystems 2 01 vaccination 465
E nergy fow 21 3 Movement 476
C arbon cycling 220 The kidney and
C limate change 229 osmoregulation 485
S exual reproduction 499
5 Evolution and biodiversity
E vidence or evolution 2 41 A Neurobiology and
Natural selection 2 49 behaviour
C lassication and Neural development 513
biodiversity 258 The human brain 518
C ladistics 2 63 Perception o stimuli 526
Innate and learned
6 Human physiology behaviour 533
D igestion and absorption 2 79 Neuropharmacology 5 41
The blood system 2 89 Ethology 5 48
D eence against inectious
diseases 3 02 B Biotechnology and
Gas exchange 31 0 bioinformatics
Neurones and synapses 31 9 Microbiology: organisms in
Hormones, homeostasis and industry 557
reproduction 329 B iotechnology in agriculture 5 65
iii
, Course book defnition The IB Learner Profle
The IB D iploma Programme course books are The aim o all IB programmes to develop
resource materials designed to support students internationally minded people who work to create
throughout their two- year D iploma Programme a better and more peaceul world. The aim o the
course o study in a particular subj ect. They will programme is to develop this person through ten
help students gain an understanding o what learner attributes, as described below.
is expected rom the study o an IB D iploma
Inquirers: They develop their natural curiosity.
Programme subj ect while presenting content in a
They acquire the skills necessary to conduct
way that illustrates the purpose and aims o the IB .
inquiry and research and snow independence in
They refect the philosophy and approach o the
learning. They actively enj oy learning and this love
IB and encourage a deep understanding o each
o learning will be sustained throughout their lives.
subj ect by making connections to wider issues and
providing opportunities or critical thinking. Knowledgeable: They explore concepts, ideas,
and issues that have local and global signicance.
The books mirror the IB philosophy o viewing the
In so doing, they acquire in-depth knowledge and
curriculum in terms o a whole- course approach;
develop understanding across a broad and balanced
the use o a wide range o resources, international
range o disciplines.
mindedness, the IB learner prole and the IB
D iploma Programme core requirements, theory Thinkers: They exercise initiative in applying
o knowledge, the extended essay, and creativity, thinking skills critically and creatively to recognize
action, service ( C AS ) . and approach complex problems, and make
reasoned, ethical decisions.
E ach book can be used in conj unction with other
materials and indeed, students o the IB are C ommunicators: They understand and express
required and encouraged to draw conclusions rom ideas and inormation condently and creatively in
a variety o resources. Suggestions or additional more than one language and in a variety o modes
and urther reading are given in each book o communication. They work eectively and
and suggestions or how to extend research are willingly in collaboration with others.
provided. Princip led: They act with integrity and honesty,
In addition, the course companions provide advice with a strong sense o airness, j ustice and respect
and guidance on the specic course assessment or the dignity o the individual, groups and
requirements and on academic honesty protocol. communities. They take responsibility or their
They are distinctive and authoritative without own action and the consequences that accompany
being prescriptive. them.
O p en-minded: They understand and appreciate
IB mission statement their own cultures and personal histories, and are
The International B accalaureate aims to develop open to the perspectives, values and traditions
inquiring, knowledgeable and caring young people o other individuals and communities. They are
who help to create a better and more peaceul accustomed to seeking and evaluating a range o
world through intercultural understanding and points o view, and are willing to grow rom the
respect. experience.
To this end the organization works with schools, C aring: They show empathy, compassion and
governments and international organizations to respect towards the needs and eelings o others.
develop challenging programmes o international They have a personal commitment to service, and
education and rigorous assessment. to act to make a positive dierence to the lives o
These programmes encourage students across the others and to the environment.
world to become active, compassionate and lielong Risk-takers: They approach unamiliar situations
learners who understand that other people, with and uncertainty with courage and orethought,
their dierences, can also be right. and have the independence o spirit to explore
new roles, ideas, and strategies. They are brave and
articulate in deending their belies.
iv
,B alanced: They understand the importance o What constitutes malpractice?
intellectual, physical and emotional ballance to Malpractice is behaviour that results in, or may
achieve personal well- being or themselves and result in, you or any student gaining an unair
others. advantage in one or more assessment component.
Refective: They give thoughtul consideration Malpractice includes plagiarism and collusion.
to their own learning and experience. They are Plagiarism is defned as the representation o the
able to assess and understand their strengths and ideas or work o another person as your own. The
limitations in order to support their learning and ollowing are some o the ways to avoid plagiarism:
personal development.
words and ideas o another person to support
ones arguments must be acknowledged
A note on academic honesty
It is o vital importance to acknowledge and passages that are quoted verbatim must
appropriately credit the owners o inormation be enclosed within quotation marks and
when that inormation is used in your work. acknowledged
Ater all, owners o ideas ( intellectual property) C D -Roms, email messages, web sites on the
have property rights. To have an authentic piece Internet and any other electronic media must
o work, it must be based on your individual be treated in the same way as books and
and original ideas with the work o others ully j ournals
acknowledged. Thereore, all assignments, written
or oral, completed or assessment must use your
the sources o all photographs, maps,
own language and expression. Where sources are illustrations, computer programs, data, graphs,
used or reerred to, whether in the orm o direct audio- visual and similar material must be
quotation or paraphrase, such sources must be acknowledged i they are not your own work
appropriately acknowledged. works o art, whether music, flm dance,
How do I acknowledge the work of others? theatre arts or visual arts and where the
The way that you acknowledge that you have used creative use o a part o a work takes place, the
the ideas o other people is through the use o original artist must be acknowledged.
ootnotes and bibliographies. C ollusion is defned as supporting malpractice by
Footnotes ( placed at the bottom o a page) or another student. This includes:
endnotes ( placed at the end o a document) are allowing your work to be copied or submitted
to be provided when you quote or paraphrase or assessment by another student
rom another document, or closely summarize the
duplicating work or dierent assessment
inormation provided in another document. You
components and/or diploma requirements.
do not need to provide a ootnote or inormation
that is part o a body o knowledge. That is, O ther orms o malp ractice include any action
defnitions do not need to be ootnoted as they are that gives you an unair advantage or aects the
part o the assumed knowledge. results o another student. Examples include,
taking unauthorized material into an examination
B ibliograp hies should include a ormal list o the
room, misconduct during an examination and
resources that you used in your work. Formal
alsiying a C AS record.
means that you should use one o the several
accepted orms o presentation. This usually
involves separating the resources that you use
into dierent categories ( e.g. books, magazines,
newspaper articles, internet-based resources, C ds
and works o art) and providing ull inormation
as to how a reader or viewer o your work can
fnd the same inormation. A bibliography is
compulsory in the E xtended Essay.
v
, Using your IB Biology
Online Resources
What is Kerboodle?
Kerboodle is an online learning platorm. I your school has a
subscription to IB B iology Kerboodle O nline Resources you will be able
to access a huge bank o resources, assessments, and presentations to
guide you through this course.
What is in your Kerboodle Online Resources?
There are three main areas or students on the IB B iology Kerboodle:
planning, resources, and assessment.
Resources
There a hundreds o extra resources available on the IB B iology
Kerboodle O nline. You can use these at home or in the classroom to
develop your skills and knowledge as you progress through the course.
Watch videos and animations o experiments, difcult concepts, and
science in action.
Hundreds o worksheets read articles, perorm experiments and
simulations, practice your skills, or use your knowledge to answer
questions.
Look at galleries o images rom the book and see their details close up.
Find out more by looking at recommended sites on the Internet,
answer questions, or do more research.
Planning
B e prepared or the practical work and your internal assessment with
extra resources on the IB B iology Kerboodle online.
Learn about the dierent skills that you need to perorm an investigation.
Plan and prepare experiments o your own.
Learn how to analyse data and draw conclusions successully
and accurately.
One of hundreds of worksheets. Practical skills presentation.
vi
,Assessment
C lick on the assessment tab to check your knowledge or revise or your
examinations. Here you will fnd lots o interactive quizzes and exam-
style practice questions.
Formative tests: use these to check your comprehension, theres one
auto-marked quiz or every sub-topic. E valuate how confdent you
eel about a sub-topic, then complete the test. You will have two
attempts at each question and get eedback ater every question. The
marks are automatically reported in the markbook, so you can see
how you progress throughout the year.
Summative tests: use these to practice or your exams or as revision,
theres one auto- marked quiz or every topic. Work through the test
as i it were an examination go back and change any questions you
arent sure about until you are happy, then submit the test or a fnal
mark. The marks are automatically reported in the markbook, so you
can see where you may need more practice.
Assessment practice: use these to practice answering the longer
written questions you will come across when you are examined.
These worksheets can be printed out and perormed as a timed test.
Don't forget!
You can also fnd extra resources on our ree website
www.oxfordsecondary.co.uk/ib-biology
Here you can fnd all o the answers
and even more practice questions.
vii
, Introduction Nature of science
This book is a companion or students o B iology
Here you can explore the methods o science and
in the International B accalaureate D iploma
some o the knowledge issues that are associated
Programme.
with scientifc endeavour. This is done using
B iology is the most popular choice o science careully selected examples, including biological
subj ect as part o the IB diploma. The study o research that led to paradigm shits in our
biology should lead students to appreciate the understanding o the natural world.
interconnectedness o lie within the biosphere.
With a ocus on understanding the nature o
science, IB B iology will allow you to develop a
Theory of Knowledge
level o scientifc literacy that will better prepare These short sections have headings that are equivocal
you to act on issues o local and global concern, ` knowledge questions. The text that follows often
with a ull understanding o the scientifc point details one possible answer to the knowledge question.
o view. We encourage you draw on these examples of
The structure o this book is closely based on the knowledge issues in your TOK essays. Of course, much
biology programme in the S ubj ect Guide. S ub- of the material elsewhere in the book, particularly in the
headings restate the specifc assessment statements. nature of science sections, can be used to prompt TOK
Topics 1 6 explain in detail the C ore material
discussions.
that is common to both S L and HL courses. Topics
7 1 1 explain the AHL ( additional higher level
material) . Topics A, B , C and D cover the content
activity
o the options. All topics include the ollowing
A variety of short topics are included under this heading
elements:
with the focus in all cases on active learning. We
encourage you research these topics yourself, using
Understanding information available in textbooks or on the Internet. The
The specifcs o the content requirements or aim is to promote an independent approach to learning.
each sub- topic are covered in detail. C oncepts are We believe that the optimal approach to learning is to
presented in ways that will promote enduring be active the more that you do for yourself, guided by
understanding. your teacher, the better you will learn.
Applications Data-based questions
These sections help you to develop your
These questions involve studying and analysing data
understanding by studying a specifc illustrative
from biological research this type of question appears
example or learning about a signifcant experiment
in both Paper 2 and Paper 3 for SL and HL IB Biology.
in the history o biology.
Answers to these questions can be found at
www.oxfordsecondary.co.uk/ib-biology
Skills topics
These sections encourage you to apply your
understanding through practical activities End -of-Topic Questions
and analysis o results rom classic biological At the end o each topic you will fnd a range o
research. In some cases this involves instructions questions, including both past IB B iology exam
or handling data rom experiments and also questions and new questions. Answers can be
use o IC T. Some o the skills sections involve ound at www.oxordsecondary. co.uk/ib- biology
experiments with known outcomes, aimed at
promoting understanding through doing and
seeing. O thers involve ideas or experimental
work with unknown outcomes, where you can
defne the problem and the methods. These are a
valuable opportunities to build the skills that are
assessed in IA ( see page 708) .
viii
,1 CE LL B I O LO GY
Introduction
There is an unbroken chain o lie rom the rst in prokaryotes and eukaryotes. While evolution
cells on Earth to all cells ound in organisms has resulted in a biological world o enormous
alive today. Eukaryotes have a much more diversity, the study o cells shows us that
complex cell structure than prokaryotes. The there are also universal eatures. For example,
evolution o multicellular organisms allowed the fuid and dynamic structure o biological
cell specialization and cell replacement. C ell membranes allows them to control the
division is essential but is carried out dierently composition o cells.
1.1 Introduction to cells
Understanding Applications
According to the cell theory, living organisms
Questioning the cell theory using atypical
are composed o cells. examples, including striated muscle, giant
Organisms consisting o only one cell carry out algae and aseptate ungal hyphae.
all unctions o lie in that cell. Investigation o unctions o lie in
Surace area to volume ratio is important in the Paramecium and one named photosynthetic
limitation o cell size. unicellular organism.
Multicellular organisms have properties Use o stem cells to treat Stargardts disease
that emerge rom the interaction o their and one other named condition.
cellular components. Ethics o the therapeutic use o stem cells rom
Specialized tissues can develop by cell specially created embryos, rom the umbilical
dierentiation in multicellular organisms. cord blood o a new-born baby and rom an
Dierentiation involves the expression o some adults own tissues.
genes and not others in a cells genome.
The capacity o stem cells to divide and
dierentiate along dierent pathways is
necessary in embryonic development. It also
makes stem cells suitable or therapeutic uses.
Nature of science Skills
Looking or trends and discrepancies: although Use o a light microscope to investigate the
most organisms conorm to cell theory, there structure o cells and tissues.
are exceptions. Drawing cell structures as seen with the
Ethical implications o research: research light microscope.
involving stem cells is growing in importance Calculation o the magnifcation o drawings
and raises ethical issues. and the actual size o structures shown in
drawings or micrographs.
1
, 1 C E LL B I O LO G Y
The cell theory
Living organisms are composed of cells.
The internal structure of living organisms is very intricate and is built
up from very small individual parts. O rgans such as the kidney and
the eye are easily visible. If they are dissected we can see that large
organs are made of a number of different tissues, but until microscopes
were invented little or nothing was discovered about the structure of
tissues. From the 1 7th century onwards biologists examined tissues
from both plants and animals using microscopes. Although there was
much variation, certain features were seen again and again. A theory
was developed to explain the basic features of structure the cell theory.
This states that cells are the fundamental building blocks of all living
organisms. The smallest organisms are unicellular they consist of j ust
one cell. Larger organisms are multicellular they are composed of
many cells.
C ells vary considerably in size and shape but they share certain common
features:
Every living cell is surrounded by a membrane, which separates the
cell contents from everything else outside.
C ells contain genetic material which stores all of the instructions
needed for the cells activities.
Many of these activities are chemical reactions, catalysed by enzymes
produced inside the cell.
C ells have their own energy release system that powers all of the
cells activities.
S o, cells can be thought of as the smallest living structures nothing
smaller can survive.
Figure 1 Coloured scanning electron micrograph (SEM) of a human embryo on the tip of a pin
2