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IGCSE Biology Coursebook

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IGCSE Biology Coursebook

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ee : CAMBRIDGE Mary Jones and Geoff Jones Cambridge IGCSE® Biology Coursebook Third edition Mary Jones and Geoff Jones Cambridge IGCSE® Biology Coursebook Third edition ‘UNIVERSITY PRESS ‘CAMBRIDGE ‘Une Printing Howse, Cambri C2 BS, United King Cambede Une re prt he Ulery of Cambie Infurersth Unersysmisiony iemiating lg ithe porto ‘lian, ing and seach a he highs ntl vc ence vocab ong © Cambie Unters res 202, 2014 ‘Tis puna copyght Subp 0 anton apn {nde povins fre cto icemtag apne ‘verona per ny ake ace hot he rien Femi Combe Ute Pes it pba 202 iti nny Repl Pr oad etal rdf hs pubeion athe Brite aay ISGN 9781 20741059.6 Paperback th CD-ROM or Wind an Ma Canbeige ives Pre ht 0 repos fr the prince o acy Riser ears pry tra ches red ons pan, {hdc pnts ht any cote on ack webu yor len ‘tun or spor natn repr pie eel real an ter ‘nal nemo enn th work coe at hc ef Se ring Canrige Univer res dcr pare the aca och Sato ‘here ise equ ay fro hs woe ter frm acing toca od tons ore ep er he wing tastes {0 eyo ae sing by enc td your schist eh Coppi esis ge (i where such ence sto where you wih exe teem fen cou edhe rte permsing of Cabs Unser Pes (uy here jou ae wed ogra hut peso ude be evsons | Grup the Copyeht esgsandPet et 198 ch ers ‘ample repescton hn poe win coin ys esol ety depute purposes of tigation ues, ‘Allen ape guess taken om pus papers repadud by person of tigers sami Example niet andallote end chpe questions were writen ye stor "GCSE etter adem of Cambie nenatnt Ean Comtrigentertoal sanintons ears pony the eae neers ‘esoteric a contaned i ds eatin Contents Introduction Acknowledgements 1 Classification 1.1 Characteristics of ving things 12 Classification 13 The kingdoms of living organisms 1A Viruses 115. Clasifying animals 1.6 Classifying plants 17 Keys 2 Cells 21 Calstructre 22 Calls and organisms 3 Movement in and out of cells 3.1 Difasion 32 Osmoris 23.3 Active transport 4 The chemicals of life 41 What ae you made of? 42 Carbohydrates 43 Fats 44. Proteins 45 DNA 5 Enzymes 511 Biologie catalysts 52 Properties of enzymes ses 4 4 “ 6 ” so SI 6 Plant nutrition 61 Types of matron 62 Photosynthesis 63 Leaves 64 Uses ofglucoe 465 Testing leavesfor starch {66 Limiting factors {67 The importance of photosynthesis 7 Animal nutrition 7A Diet 72 Digestion 73 Teeth 74 Thealimentary canal 75 Assimilation 8 Transport in plants AL Planteansport systems 2 Water upake 83 Transpiration £84 Transport of panufactured food 9 Transport in animals 9.1 Circulatory stems 92 Thebeart 93 Blood vessels 94 Blood 195 Lymph and tse fd 10 Pathogens and immunity 10.1 Patbogens 102 Body defences 103 Theimmunesystem asaressS B 7% 78 0 2 ® 28 88 02 106 108 109 us. 47 ma 127 es bs ns 11 Respiration and gas exchange 111 Respiration 112 Gas exchange in humans 113 Breathing movements 12 Excretion 121 Exeretory products 122 Nitrogenous waste 123 The human excretory sytem 13 Coordination and response 13. Coordination in animals 132 Thebuman nervous system 133 Receptors 13 The endocrine system 135 Coordination and response in plants 14 Homeostasis MLL Maintaining the internal environment M42 Control of body temperature 11.3 Contra af blood glucose concentration 15 Drugs 151 Whatisa drug? 152 Medicinal drugs 153 Misuse of drugs 154 “Tobaceo smoking 16 Reproduction in plants 161 Asexual eproduction| 162 Sexual reproduction 163 Sexual production in lowering plants 16:4 Comparing sexual and asexual reproduction 17 Reproduction in humans 17.1 Human reproductive organs 172 Fertilisation and development 17.3 The menstrual cycle 174 Birth control 175 Sexually transmitted infections 18 Inheritance 181 Chromosomes 182 Calldvision 183 Inheritance 184 DNA and protein synthesis BED oe cctien 140 ut vy M6 153 15 15 155 161 182 182 165 170 m 178 19 179 1 188 189 189 190 12 197 198 198 200 208 212 213 as m2 225 230 231 231 235, 23 19 Variation and natural selection 247 19.1 Variation 248 192 Adaptive features 250 193 Selection 253 20 Organisms and their environment 264 20.1 Ecology 285, 2022 Energy flow 265 2033 Natrient eyes 2 2044 Population size m 21 Biotechnology 280 21.1 Whats biotechnology? 281 212 Using yeast 281 213 Making use of enzymes 282 214 Penicillin 284 215 Genetic engineering 26, 22 Humans and the environment 292 2211 Food production 23 222 Habitat destroction 295, 223 Pollution 299 224 Conservation a7 Answers to questions 318 Glossary 330 lex 339 ‘Terms and Conditions of use for the CD-ROM 347 D-ROM Study and revision halls Multiple choice tests Practice exam:style papers and marking schemes Glossary [Notes on Activities for Teachers Technicians Self-asessment checlists Activites Answers to Cousebookend-o chapter questions Revision checklists Animations _— - Introduction ‘Thishook as been writen thelp you todo wellin your Cambridge Intemational Examinations GCSE Biology examination (0610). We hope that you enjoy ‘sing ‘Thebook can also he used with the Cambridge‘ level Biology syllabus (090), (Core and Supplement ‘Yur teacher wil ell you whether you are studying just ‘the Core part ofthe Biology ylabus or whether you ae studying the Supplement as well you study the Core only, you wil be entered for Papers and 3 nd either Paper Sor 6, and can geta maximum of Grade C. Ifyou alo study the Supplement, you may be entered for Papers 2 and 4, and ether Paper Sor 6,and willbe able to get a maximum of Grade A. The Supplement (© smote inthis book is marked by eter San brown © ars in the manga, lke this. Definitions "There are quite lot of definitions in the IGCSE syllabus ‘that you need to learn by heart. These are all nth ‘book, at appropriate points in each chapter, inside boxes ‘with a heading ‘Key definition: Make sure you learn these carefully. Questions Each chapter has several sets of Questions within it Most ofthese require quite short answers and simply test f you have understood what you have jus ead (or ‘what you have just been taught). At the end of each chapter there are some longer ‘questions testing a range of material from the chapter, ‘Some of these ate past questions from Cambridge exam Papers or are ina similar style to Cambridge questions Actes Each chapter contain Activites, These wil help you to develop the practical skills that willbe ested in your IGCSE Biology examination, There are more Activities ‘onthe CD-ROM, These are marked with this symbol: “There ae two posible exams to test your practical ski, called Paper and Paper 6. Your teacher wil tll you which ofthese you will be entered for. They are equally dificult, ard you can get upto Grade A* on eather of them, Yor should try to do the Activities no ‘matter which of these papers you are entered fo. Summary ‘Atthe end of each chapter, there ia short ist of the _main points covered inthe chapter. Remember, though, that these are only very short summaries and youll ned to knove more detail than this to do really well in the exam, The @-ROM Ther isa CD-ROM in the back ofthe book. You'll also find the Summaries on the CD-ROM. You can use the revision checlistson the CD-ROM to check off how fa you have got with karning and understanding each idea "The CD-ROM aso contains ast of interactive ‘multiple-choice qustions testing whether you know and understand the material from each chapter ‘You'l find someself-asessment checklists on the (CD-ROM too, which you can print off and use to assess yourself etch timeyou observ and draw specimen, construct resltschat, draw grap froma sct of results or plan an experiment. These reall very {important kills ard by using these checklists you should be abet improve your performance until you can do thems almost perfect everytime. "Thor are some sggestions on the CD-ROM about how you can give yourself the very best chance af doing wall in your exams by studying and revising carefully ‘There are aso som practice exam papers Workbook ‘There is a workbockto go with this textbook, Ifyou have one, you wil nd it really helpful in developing your skills, such ashanding information and solving problems aswell as ome of the practical skills Acknowledgements ‘Cover image/Frans Lanting, Mint Images/SPL, p. 1 Alamy;2 Geof Jones; pp. 7% 76 Alamys . 11 Geof Jones: p15 Geoff Jones: p. 17 Geoff Jones, 18 SPL p. 208, 206 Eleanor Jones p. 21 Biophoto Astocates/SPL; p22, 225.22br SPL: p. 26 PL: p. 28 Alamys p. 34 Geoff Jones: p. 40 SPL; p.42 SPL; p43 SPL; p44 Alamys pS SPL; 46,46 SPL: p. 49 Alamy;p. 58 SPL; p.61f Biophoto Assocate/SPL;p61b SPL; p.6tr Andrew SyrediSPL; p65 Nigel Catin/Alamy; p67 Alamy: p.73 SPL; p. 75 73-7.6 Geo Jones 71 Alex Segre) Alamy;p.77r Images of Afica Photobank/Alamy; p. 87 Blophoto ‘Associats/SPL; p. 88! SPL; p&8r SPL; p. 93 Alamys p. 94 Andeve Syred/SPL; p. 95 LC. Revy/SPL; 961 SPLsp. 96b SPL; p. 106 Alay; p. 110 Alamy; p 112 Alamys p14 Janine Photoibrary Alam; p. 115 Prof. P. Mott/Dept of Anatomny/University “La Sapienza Rome/SPL; pp 118, 120,121 Phototake Inc/Alamy; p. 127 Alamyp. 129" Alamys 1.129) Alay p. 130 Alamy; p 131 Alamyy p. 1321 Alamys . 132r Alamy:p.136 Alamy: 1.137 Alam p. 140 Alamy; . 180 Rick Rickman/NowSport/Corbis p. 153 Alamys 1.61 SPLp. 164 Wendy Lee; p. 165 Visual Idens/Nora/Corbisp. 175 SPL: p.178 Alamy: ‘p85 SPL. 186rSPL;p, 188 Alamys p. 189f CNRUSPL: p.189b Alam; p. 1911 Zama ress/Zumna/Corbis 1917St Bartholomews HosptalSPL; p. 192 SPL; pp 1944 1947 Biophoto Assocites/SPL:p. 195 SPL; p. 197 Alamy; p, 201 Geoff Jones; p. 202" Alamy: .202b Pictox/Alamys p. 204 SPL; p. 208 Alamy; p.212¢ SPL; p.2126 SPL; p. 215 Alamy: 1.219 Alay p. 225 SPL; p. 230 Alam; p. 2311 Chery PowerlSPL; 2317 CNRUSPL: 1.282 Leonard Lessin/PBPA/SPL:p. 239 Alamy’ p. 2471 Alamysp.247r Alamysp. 248 mr ‘Wendy Lee; p. 2481 Imagebroker/ Alamysp.248b Sam Sangster! Alamy; p, 251! Alamy; 25ler Alamy; p.251br Geoff Jones p. 2531 Jayanta Dey/epa/Corbis;p 2531 Mary Evans Picture LibraryAlamys p.254 Pat Tom Leeson/SPL:p. 255 Stephen Dalton/NHPA; 257 Agence Nature/NHPA; p.259tb Geoff Jones, 259br Terry Matthews/Alamy; 262 Alamys p, 264 SPL; p. 278 SPL; p. 280 SPL; p. 281 SPL; p. 2821 SPL; p.282r SPL; 1.283 SPLzp. 287 SPL: p. 292 Alamy; p. 2930! Davi South/Alamy 298 David Froriee Phoolbrars Incl Alay; p, 294 SPL; p. 294tr Alamys 2941 SPL; p.295¢ Alans p295b Alamy; p.2961 Gideon Mendel for Action Aid/Corbis p.296r Alamys 207 Alamy;297HI Sylvia Cordaiy Photo Library Ltd/Alamy; p.297t Geof Jones .297br Geoff Jones p 3011 Lou Linwo Alay: p.301r im West Alamy; p. 303, BlickvinkelAlay;p. 305 Nigel Cattlind Alay: p. 306 Alamys p. 308 Alamy;p. 312 Alam. 313 Alamy p.314! Alamy p 14H Alamysp.314br Alamy: p.315 Alamy Abbreviations SP. “Layout and illustration by Greenill Wood Studios a 7 Classification ‘the characteristics of living things naming organisms using the binomial system how tvng organisms are lassied how to use dichotomous keys to identity organisms. ‘The puzzle ofthe platypus 11788, Boitih ster arrived in Australia. They were amazed by many of the animals that they sa, and. stange animal wit fur, webbed fet and a ‘beak was among the most puzzling (Figure 1.1). People had already been living in Australia for almost 50000 years, and diferent groups ofthese Indigenous people had various names for this animal sich as dulawarsung. But the Bish arrivals were not satisfied with jst giving the animal a name. “They wanted to casi - ta decide which group of animals t belonged in, ‘And thie was where the problem begen The animal had s beak and webbed fet, like a duck. t had fur ikea mole. No-one knew whether aid ‘eggs or gave birth to live young. So was ita bird? Was ita mammal? No-one could decide, In 1799, a dead specimen ofthis strange animal vas taken to England, where it was stadied by Dr George Shaw To begin with, he thought it was 2 hoax. He looked very carefully see ifsomeone had stitched the beak onto the hea, but no ~ it was clealy a genuine part ofthe animal. De Shaw gave the animal a Latin name, Platypus ‘natin. Patypas means lat-footed’ and ‘anatinus rans like duce However, someone then pointed out thatthe name Platypus had already been taken, and belonged toa species of beetle So another name was suggested by a German scientist, who gave it the name Ornithoriynchusparadasus. The fist ‘word means ‘nose Kk a bird’ and the second means ‘puarling. this tke Latin name that is wed forthe animal today. Although the Latin name Platypus could not be ‘used, peopl stil elle the animal platypus. In ‘the fllowing years proof was fund that platypuses lay gs, rather thas giving birth to live young However, they feedtheir young on milk, which ‘sa characters feature of mammals, Scents eventually decided classify the platypus asa ‘mamma, despite sod beak and the fact that it layseggs It was pinto anew group of mammals, called monotremes which ls includes the echidnas (spiny anteaters) ee sey te ig comet; cnt QI 1.1 Characteristics of living things logy isthe study of ving things which ar ofen called organisms. Livng organisms have seven eres or characteristics which make them diferent rom Growth Alors bal saan etre bythe growth feel nd oy ang new (et thei bo. xeretion Alocpiiens rosie unwanted or toss waste Prose sr arent ther Freabelc enctons and ese tbe removed forthe bod Fipse 12 unc ig opnins trae now orpriore Key definitions ‘movement ~ an ation by an organism causing & change of poston or place respiration ~ the chemical reactions in cells that break down nutrient molecules and release energy sensitivity ~ the ability to detect and respond to changes in the environment srowth ~ permanent increase in size Movement Allorgatisns are able to move {aoe excane Moa animale an move fe ‘hoe body rom lace o place ne pants an Slow mow pars of sles. ‘Orpnims are ale to ‘objects that ate not alive (Figure 1.2). The definitions of ‘these characteristics ate shown in the boxes below and. ‘on the oposite page. You should lear these definitions now but you wil find ot mach more about each of ‘them ater in this book, Sensitivity Allon pik up ‘foration about anges inh fearon and vac ‘ale bere bom thee bre ow gate ad Cronmerc and them fhe subahces nie thar provieeneray er marcato reese energy ht to make new al. Soy cane, reproduction ~the processes that make more ofthe same kind of organism ‘exrotion ~ emoval fom organisms of toxic ‘materials and substances in excess of requirements trtion~ taking in of materials fr energy growth sand development Key definitions | movement ~ an action by an organism or part ‘ofan organism causing change of position ‘or place respiration ~ th chemical reactons in cells that break doven nutrient molecules and release energy for metabolism sensitivity ~ the ability to detector sense simul in the internal or external envionment and to make spproprite responses Inaddition to these soven characteristics, living “organisms have another feature in common. When we study living organisms under a microscope, we can see that they are all made of ell. These celal have cytoplasm acell membrane 1 chemical called DNA, making up thelr genetic material © 6 ribosomes, which are used for making proteins inside the cll, + enzymes that are used to help the cll to cary out | anaerobic respiration, You can find out more about the stuctre of cll in Chapter 2 1.2 Classification Clasification means puting things into groups. There ‘are many possible waysin which we could group living ‘organisms. For example, we could putall the organisms ‘vith legs into one group, andl those without eg nto nother. Or we could put all red organisms into one ‘group, and all lac ones into another. The first of these ideas would be mach more useful to biologists than the second. The main reason fr classifying living things isto make teaser o study them. For example, we put Thumans, dogs, horse and mice into ane group (the ‘mammals because they shave certain features (for ‘example, having har) that are not found in other groups, We think that all mamma share these features because they have all descended from the ame ancestor growth ~a permanent incense in ize nd dry mass by a incre n el omber rel seo bath cxereton ~ removal fom organisms ofthe waste products oft (chemical actions in Eels incluing repiration oxic materia and Substances ines of oiements Inriton~ oki in of material for nergy. grovth nd deetopmer plats ei ight aon Ahxde water and onsen need organic compounds and ins an wally ned water ‘that lived log age the ancestor that they all share {scalled a common ancestor. The comman ancestor that gave rise to al the mammals ved more than 200 million years go. ‘We would therefore expect all mammals to have ‘dies that have similar structures and that workin similar ways, we finda new animal that as hair and suckes its young on mill then we know that itbelongs in the mammal group. We wil already know alot about it even before wehave studied ita al Using DNA to help with classification ° Inthe past the ory ways tht bilgi could side ‘hich onisms wee mst cosy relate each ther ‘rasta sty the racur of ther bodies They looked Carefly t their morphology he oval fom and Shape of their bokes, uch ar whether they ad es or ‘ing and theism he dae body struct Inch could be dermis dsectin). West we these methods fcassstion foday Ba we ow have new tol to hlpto work out evetionaryesionshps, and one ofthe mes powerless the tidy ofDNA DNA sth chemi fom which ur chromosomes are mae, the netic mater pas on fom cone gnestion othe next. Yow can read moe about estate in Caper were yo wil i ot that cach DNA molec made wp of strings of salle Tulales contaning for dierent be These thse called A, Gand canbe ranged in any corer Bilogits can compare the eiencesofbaies ——: © tn the DNA of organisms rom tw dierent species, ‘The more smile the hase sequences the more osly selatd th peces ar to one another They have amore teceat common ancestor than species hat have DNA base sequences tat Sequences of ino aid in proteins an be sedi the same vay. re ese similar. The smarts in The classification system ‘The ist person to try to clasify organisms in a scientific way wasa Swedish naturalist called Linnaeus, He introduced his system of classification in 1735, "He divided all the diferent kindof living things into {groups called species. He recognised 12000 diferent species, Linnaeus species were groups of organisms that shared the same appearance and behavior, We still ‘se thie system today Biologists do not ays agree ‘on exactly how to define a species, but usually we say ‘that organisms belongto the same species ifthey can breed together succesfully, and the ofpring tat they BEE) cesses ‘produce can also breed. Species are grouped into larger groups called genera (Gingular: genus) Each genus contain several species ‘wth similar characteristics (Figure 13). Several genera are then grouped into fal files iota orders, ‘orders into clases, cases into phyla and finally phy into kingdoms, Some ofthe more important groups are described in this chapter, Figure 1.3 shoves five animals that all belong othe ‘manual order You cans that they all ave hai, which ia characteristic feature of mammals, The animals have been clasifled into two groups — horse-tke mammals and dog like mammals. (What features do you think lifer between these two groupe?) “The orse-like mammalsall belong othe genus Equus. The dog like ones belong to the genus Cans seus Equss =~ ‘The binomial naming system Linnaeus gave every species flving organism wo ‘names, writen i Latin This calle the binomi -ystm, The first name is the name ofthe genus the ‘organism belongs to, and always has a capital letter. The second name isthe name of ts species, and aways basa smal eter. Tie two-word name i called a binomial. For example,a wolfbelongs to the genus Canis nd the species lupus Its binomials Cas apus “These names are printed in alles. When you write a Latin name, you cannot writen tales, so you should underline it instead. The genus name can be abbreviated like his: Caps @ Question 1.1 ‘The table shows how wo organisms — ‘monarch utterly anda giant pangolin — ste classified, {@Usethe informatiton inthe table to suggest ‘whether these two organisms are not related a all distantly related or cosely ‘elated. Expltin how you made your deision 1b Write down the genus ofthe giant pangolin © Use the Internet or a textbook to find out Iowa human ie clasfed, Writeit down ina table like the one shown onthe right Monarch butterfly \ \ species a group of organiems that cn reproduce and produce fertile offspring binomial system ~ an internationally ageced sjstem in which the scientific name of an ‘organism is made up of two parts showing the ‘genus and spedes Do take cate to ste Latin names (binomials) correctly You wl often see them written wrongly {nthe medi! Ye should always use a capital letter forthe fr name and a small etter forthe snimsl seterates insecs mammals Lepper Pholidota (bates and moths) Danadae Manidae Danae Mans amaze plexippus | Manis gigantea owe: cotate 1.3. The kingdoms of living organisms ‘Animals Animals (Pigure 1.4 are usualy easy to recognise. Most animals can move actively, hunting fo food. Under the _microscope, we can sce that their ells have no cel wall. ‘Some animals have, in the past, been confused with plants. Fra very long time 8 anemones were classified as plants, because they tend o stay fixed in one place, and their tentacles look rather like fawer petal. Now we know that they are animal (Characterinies: ‘ multicellular (their bodies contain many cls) { callshavea nucleus, but no cell alls or chloroplasts + feed on organic substances madeby other living Fg 4 Sone amp of ims Plants, ‘The plants that are most familar to us ate the lowering plants, which include most kinds of tes. These plants have leaves, stems roots ad lowers (Figure 1.5) However there are other types of plans including ferns and mosses - that donot have lowers. What all of them have in common is the green colour, caused bya pigment called chlorophyll This pigment absorbs nergy from sunlight, nd the plant can wse this energy to make sugars, bythe proces of photosynthesis. As they do not need to move around to get their fod, plants ar adapted to remain in one place. They often have a spreading shape, enabling them to capture as ‘much sunlight energy as possible Characernis: multicellular 4 cells havea nucleus, cll walls made of cellulose and fen contain chloroplasts + fed by photosynthesis “# may have roots, stoms and leaves, DD ose sc ie Fire 13, swamp ep @ Questions 1.2 “The photograph below showsa sea anemone. Explain why people usd to think that sea snemones were plats 1b Explain how using a microscope could help you to confirm tat sea anemones ae animal 113 “The photograph below shows a plant called a Liverwort. Liverworts do not have roots or proper leaves. They do not have lower, Suggest how you ‘ould show that liverwort belongs tothe plant kingdom, Fungi Fora very long tims, fungi were classified as plants However, we now know that they re realy very diferent, and belorg in their own kingdom. Figure 1.6 shows the characteristic features of ung, ‘We have found aay different uses to make of fang ‘Weeat them as mushrooms. We us the unusual fungus yeas to make ethavol and bread. We obtain antibiotics such as penieilin fiom various diferent fangs Some fungi however, ar harmful Some ofthese cause food decay, while a few cause diseases, Including ingworm and athlete’ fot Fungi donot have chlorophyll and do not photosythesise Instead they feed saprophytically, oF parasiticaly, on organic materia ike foe, human foods and dead plans or animals Characteristic: ‘usually mulicelber (many-celled) 4 have maces 4 have cel walls, rot made of cellulose 4 donot have chlerophyl + fed by saprophytic or parasitic nutrition feaig spores eval pt en 18 Sone camper eg @Protoctista “The kingdom Protoctista (Figure 7) contains quite a mixture of onganisms. They all ave clls witha nucleus, but some have plant like cells wth chloroplasts and. cellulose cell walls, while others have anima-lke cells ‘without thes festures. Most protoctiss are unieluae (made of just single cel) but some, sucha seaweeds, sre mulielalar (Characteristics: ‘ muliceiulr or unicellular 4 cells havea nucleus 4 cells may or may not havea call wall and chloroplasts 4 some feed by photosynthesis and others feed on ‘ongaic substances made by other organisms call mentrane Fire? Sone camp ol ps. Prokaryotes, Figure 1.8 shows some bacteria, Bacteria have cll that ane very diferent fom the cel of al other kinds of ‘organism, The moet important dference i tha they do nothaves nucleus ‘You will met bacteria at various stages in your biology course. Some of them are harmful to us and «cause diseases such as tuberculosis (TB) and cholera “Many more however, are help, You wll find out shout their sel roles in the carbon cyl and the itogen cele, n biotechnology, in the treatment of sewage to make i safe to eat into the environment snd in making insulin forthe treatment of people with diabetes, ‘Some bacteria can catry out photosynthesis. The ‘oldest fossils belong to this kingdom, so we think that ‘they were the frst kinds of onanism to evolve. Characters: + often unicellular (single-celled) + have no maces + have cell walls, not made of lulose + have no mitochondea Fre 1 Sone angi fc © 1.4 Viruses ‘You have almost certainly had an illness caused by virus. Viruses cause common diseases such a colds and ‘influenza, and also more serous ones such as AIDS. ‘Viruses ae not nocmlly considered tobe ave, because they cannot do anything other than just exist, sani they get inside ving cl. They then take over the calls machinery to make multiple copies of themselves. ‘These new viruses burst out ofthe cll and invade others, where the proces is repeated, The hos cells ‘usualy killed when this happens. On thei own, viruses cannot move feed, excrete, show sensitivity, grow or reproduce, Figure 1.9 shows one kind of virus, Its not made of call itis simply apiece of DNA or RNA (a chemical similar t9 DNA) surrounded bya protein coat It ‘hugely magnified in this dlagram. The scale bar represents length of lOnanometres One nanometre is 110mm. In other words, you could line up -more than 15000 ofthese viruses between two ofthe inet arson youre, 1.5 Classifying animals Figure 1.10 show some ofthe majo groups ino which the animal kingdm i classified. igre 110. Cate te anil Mego Phylum Vertebrates "These are animals with a supporting rod running along the length ofthe body. The most familiar ones havea po = brckbone and recalled vertebrates. as Fh “he fish Figure 1.1) ll ive in water, xcept for one oF et, two ke the mudskppr, which can spend short periods Na of time breathing air. i aay Characteristics: 4 vertebrates wit seal sin — | + havegits = have fins, Ppet 19 Desa = © Questions = ——— © 1.4 Whyare viruses not generally considered tobe living things? 15 State one similarity and one difference between the calls of fungus and the eel ofa plant 1.6 How do the cel of bacteria difer fom the cells of plants and animalst Fire La lass Amphibians Although most adalt amphibians live on land, they slays go back tothe water to breed. Frogs, toads and ‘slamandees are amphibians (Figure 1.12). Characters: ‘vertebrates with moist salts skin 1 gs li in water, larva (tadpole) lies in water 4 adulofen lives on land ¢ larva has gil adult as longs. th ie san lass Reptiles “Those are the crocs, lizards, snakes, turtles and tortoises (Figure 1.13). Reptiles donot need to go back tothe water to reed because their eggs ve a waterproof shell which stops them from drying out Characteristic: 1 vertebrates wit say skin 1 Jay eggs with rubbery shel say sin ge Asie BED) en scsesy Chass Birds ‘The birds (Figure waterproof shells Characteristic: 1 vertebrates with feathers + farslimbs have become wings 4 lay eggs with hard shells + endothermic + haveabeak ‘heart has four chambers. 14), ke reptiles ly eggs with gue 04 aie ‘Cass Mammals “Thisis the group that humans belong to (Figure 115). Characters: 1 vertebrates with hale 4 havea placents {young feed on milk from mammary glands endothermic 4 havea diaphragm 1 hearths four chambers 1 have diferent types ofeeth incisors, canines premolars and molar) Pipes LIS Arvo angi ofa mama Phylum Arthropods Arthropods are animals with jointed legs, but no ‘backbone. They area very successful group, because they havea waterproof exoskeleton that has allowed them tolive on dey land. There are more kinds of ‘rtropod in the word than all the other kinds of animal put together. Characteristics 4 several pir of jointed lege 4 exoskeleton, Insects Insects (Figure 1.16) area very succesfl group of animals. Their success is mostly due to ther exoskeleton and tacheae, which are very good at stopping water from evaporating from the insects bodies, so they can live in very dey places. They are mainly terrestrial (and-tiving). Characteristic: ‘arthropods with three pais of jointed legs + two pr of wings (one ofboth may be vestigial) 4 breathe through tracheae {body divided into head thorax and abdomen, Iootsteg Crustaceans ‘These are the crabs,lobsters and woodhce. They breathe through gil, so mest ofthem livin wet places and ‘many are aquatic Characters 6 arthropods with more than four pairs of jointed legs 4 not milipedes or centipedes breathe through gs. ibe crab excaeleton containing, ‘alum ake oa Tem Fie 17 tn camped a scan Aracnids “These are the spien, ticks and scorpions They are Iand dwelling orgarisms Characteristics: 4 arthropods with ‘ur pais of jointed legs ‘+ breathe through ls called book lungs igus 118d campe stan om cxitctn CE Myrapods These ae the centipedes and milipees. Characteristic: + body consists of many segments + each segment has jointed legs Stele gan) tay oes age on oo Schaeenee Bem igre acpi ta O Questions = ——— (17 Lis thre ways in whic ll mama ier from all bids 1.8 Esplin why bats ae clase a mammals, 1 eventhough they have wings 1.6 Classifying plants ‘Wehave seen that plans ronan that have cal with cel vals made of cele. AY east some Parts ofa plant are re. The ren color iscaused Byapiment called chlrophy which bors nergy fom sunlight. The plant ses this energy o take gos, using carbon dns nd water om {tervronment Ts scaled photons Plants include smal organisms such as mosses, aswell fens (Figure 120) and lowering plans (Figure 1.20 OFems ers eee cle fon. They dont prods flowers but epodac by ems pre predacedon the under ofthe ond, Garter @ pln ith ot ems and ees $ fees cl ons | 4 treo 1 reproduce by spores 1 Fer ond poring wih spores Fine 120, Av oan eaten Flowering plants ‘These ate the plants that ae most fla tous. Tey can be tiny or very large ~ many tres are flowering plants, Characters: ‘plans with eoot, stems and leaves + reproduce sexually by means of flowers and seeds ‘seeds ae produced inside the ovary inthe lower lowering pants can be divided into two main groups, the monocotyledanous plants and the dicotyledonous plans, ‘often abbreviated to monocots and deo (Figure 121). “Monocots have only one cotyledon in their seeds (page 205) “They usualy have «branching rot system, and offen have leaves in which the veins run in parallel to one another, Dcots have two coyledonsin ther sods, They frequeily have a ap rot system, ad their eaves are ofen broader than those of ‘monocots, and ave a network of branching veins. Fig 121 Rowing os Biologists need ta beable to lok closely at specimens ~ which might be whole organisms, ‘or jst part ofan organism ~ and note significant features of them. Is also important tobe able to make simple drawings to record these features. ‘You dost have be good at art tobe good at biological drawings. A biological drawing needs tobe simple but clear, You willbe provided witha specimen ofan snimal to draw | ‘Look arefilly atthe specimen, and decide ‘what group of animals it belong to Jot down the festures ofthe organism that helped you to clas it Makes larg, clear drawing of your organism. ere are some pois to bear in mind when you draw, { Make good us of the space on your sheet of paper your drewing shoul be larg. However, do eave space around its that you have roam. forlabels Always use a sharp HB pencil and havea good eraser with you. Keep all lines srgle and clear. 4 Dorit use shadirg unles itis absolutely necessary Doni use colours, ‘Take time to getthe outline of your drawing correct it showing the right proportions. "Nove label your drawing to show the features ofthe organismthat are characteristic ofits classification grup. You could also abel any features that help the organism to survive in its environment. These are called adaptations. For ‘example, if yourarganism isa fish you could label ‘scales ovedapping backwards, to provide a smooth, steamined surface for sliding through the water “Here are some points to bear in mind when you label a diagram, 4 Usea ruler to daw cach label ine, 4 Make sure the ead ofthe label line actually touches the structure being labelled. 4¢ White the labelshorizontally. 4 Keep the labels wel away fom the edges of your drawing ons onan Activity 1.2 CCleulating magnification ska 1033 Observing, easing sd rece Drawings of biological specimens are usually ‘nade at a dfetent size from the rel thing tis {important o show this on the diagram, "The magnification ofa diagram is how much large it is than the ral thing. siee of drawing Saw of eal object For example, measure the length of the spider's body in the diagram below. You should fnd that it ‘40mm long. ‘magnification = “The eal spder was 8mm long So we ean

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