ALL_IB_Biology_Essay_Questions_.docx

IBBiologyHLEssayQuestions UNIT 1: CELL BIOLOGY 31.1:INTRODUCTIONTOCELLS 31.2:ULTRASTRUCTUREOF CELLS 41.3:MEMBRANE STRUCTURE 61.4:MEMBRANE TRANSPORT 71.6:CELL DIVISION 8 UNIT 2:MOLECULAR BIOLOGY 92.1:MOLECULES TO METABOLISM 92.2:WATER 102.3:CARBOHYDRATES ANDLIPIDS 102.4:PROTEINS 112.5:ENZYMES 122.6:STRUCTUREOF DNAAND RNA 122.8:CELL RESPIRATION 142.9:PHOTOSYNTHESIS 14 UNIT 3:GENETICS 163.1:GENES 163.2:CHROMOSOMES 163.3:MEIOSIS 173.4:INHERITANCE 17 UNIT 4:ECOLOGY 194.1:SPECIES , COMMUNITIES ANDECOSYSTEMS 194.2:ENERGY FLOW 194.3:CARBON CYCLING 204.4:GREENHOUSEEFFECT 20 UNIT 5:EVOLUTIONAND BIODIVERSITY 215.1:EVIDENCEFOREVOLUTION 214.2:NATURAL SELECTION 225.3:CLASSIFICATIONOF BIODIVERSITY 23 UNIT 6:HUMAN PHYSIOLOGY 266.1:STRUCTUREOF THE DIGESTIVE SYSTEM 266.2:THE BLOOD SYSTEM 286.3:DEFENSE AGAINST INFECTIOUS DISEASES 306.5:NEURONS AND SYNAPSES 326.6:HORMONES , HOMEOSTASIS AND REPRODUCTION 35 UNIT 7:NUCLEIC ACIDS 377.1DNASTRUCTUREAND REPLICATION 377.1:TRANSCRIPTIONAND GENE EXPRESSION 397.3:TRANSLATION 39 UNIT 8:METABOLISM , CELLRESPIRATIONANDPHOTOSYNTHESIS 41

8.1:METABOLISM 418.2:CELL RESPIRATION 428.3:PHOTOSYNTHESIS 45 UNIT 9:PLANT BIOLOGY 499.1:TRANSPORTINTHE XYLEMOF PLANTS 499.2:TRANSPORTINTHE PHLOEMOF PLANTS 529.3:GROWTHIN PLANTS 529.4:REPRODUCTIONIN PLANTS 52 UNIT 10:GENETICS AND EVOLUTION 5410.1:MEIOSIS 5410.2:INHERITANCE 5510.3:GENEPOOLS ANDSPECIATION 56 UNIT 11:ANIMAL PHYSIOLOGY 5811.1:ANTIBODY PRODUCTIONAND VACCINATION 5811.2:MOVEMENT 6011.3:THE KIDNEYAND OSMOREGULATION 6211.4:SEXUAL REPRODUCTION 63 Notes: 2

Unit1:CellBiology 1.1:Introductiontocells 1. Discusspossibleexceptionstocelltheory. 4marks ▪ skeletalmusclefibersarelarger/havemanynuclei/arenottypicalcells▪ fungalhyphaeare(sometimes)notdividedupintoindividualcells▪ unicellularorganismscanbeconsideredacellular▪ becausetheyarelargerthanatypicalcell/carryoutallfunctionsoflife▪ sometissues/organscontainlargeamountsofextracellularmaterial▪ e.g. vitreoushumorofeye/mineraldepositsinbone/xylemintrees/otherexample▪ statementofcelltheory/alllivingthings/mosttissuesarecomposedentirelyoftruecells 2. Eukaryoticcellshaveintracellularandextracellularcomponents.Statethefunctionsofonenamedextracellularcomponent. 4marks nameofcomponent:1max ▪ e.g.plantcellwall/cellulose/interstitial▪ matrix/basementmembrane/glycoprotein/bonematrix; functions:3max EITHER ▪ e.g.(plantcellwall)strengthens/supportsthecell/plant(againstgravity);▪ preventstheentryofpathogens;▪ maintainstheshapeofplantcells;▪ allowsturgorpressure/highpressuretodevelopinsidethecell;▪ preventsexcessiveentryofwatertothecell; OR ▪ helpscellstosticktogether/adhere;▪ neededtoholdcells/tissuestogether/exampleofcells/tissuesholdingtogether;▪ formsinterstitialmatrix/formsbasementmembranetosupportsinglelayersofcells;▪ e.g.aroundabloodcapillary;▪ forms(partofthe)filtrationmembraneintheglomerulus; 3. Explainhowthesurfacearetovolumeratioinfluencescellsizes. 3marks ▪ smallcellshavelargerratio(thanlargercells)/ratiodecreasesassizeincreases▪ surfacearea/membra