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BIOLOGYWritten examination
Friday 3 November 2017 Reading time: 9.00 am to 9.15 am (15 minutes) Writing time: 9.15 am to 11.45 am (2 hours 30 minutes)
QUESTION AND ANSWER BOOK
Structure of bookSection Number of
questionsNumber of questions
to be answeredNumber of
marks
A 40 40 40B 11 11 80
Total 120
• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpenersandrulers.
• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.
• Nocalculatorisallowedinthisexamination.
Materials supplied• Questionandanswerbookof39 pages• Answersheetformultiple-choicequestions
Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname andstudent numberasprintedonyouranswersheetformultiple-choice
questionsarecorrect, andsignyournameinthespaceprovidedtoverifythis.• Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.• AllwrittenresponsesmustbeinEnglish.
At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.
Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.
©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2017
SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2017
STUDENT NUMBER
Letter
2017BIOLOGYEXAM 2
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eaQuestion 1
Considerthestructureandfunctionalimportanceofproteins.Whichoneofthefollowingstatementsaboutproteinsiscorrect?A. Achangeinthetertiarystructureofaproteinmayresultintheproteinbecomingbiologicallyinactive.B. Proteinswithaquaternarystructurewillbemoreactivethanproteinswithoutaquaternarystructure.C. Twodifferentproteinswiththesamenumberofaminoacidswillhaveidenticalfunctions.D. Denaturationwillaltertheprimarystructureofaprotein.
Use the following information to answer Questions 2–4.ThelacoperonwasoriginallyidentifiedinEscherichia coli.Thelacoperonhasthreestructuralgenes:lacZ,lacY andlacA.ThelacZgenecodesfortheproductionoftheenzymeβ-galactosidase,whichcatalysesthebreakdownoflactoseintoglucoseandgalactose.Belowisadiagramthatshowstheorderofthegenesfoundinthelacoperon.ThedotsrepresenttheDNAnucleotidesbetweenthegenes.
……
regulatory gene……
promoter gene operator gene lacZ lacY lacA……
Question 2Tobegintranscriptionofthethreestructuralgenes,RNApolymeraseneedstobindtotheA. operatorgene.B. promotergene.C. regulatorygene.D. structuralgenes.
Question 3AmutationintheregulatorygeneofthelacoperonmayresultinA. inhibitionoftheoperatorgene.B. RNApolymerasenotbeingabletoperformtranscription.C. thelacoperonswitchingoninthepresenceoflactoseonly.D. productionofarepressormoleculethatisunabletobindtotheoperatorgene.
SECTION A – Multiple-choice questions
Instructions for Section AAnswerallquestionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrectorthatbest answersthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.Unlessotherwiseindicated,thediagramsinthisbookarenot drawntoscale.
3 2017BIOLOGYEXAM
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Question 4WhenlactoseispresentinE. coli,thelactosemoleculesarerearrangedtobecomeallolactosemolecules.Followingthisrearrangement,thestructuralgenesinthelacoperonaretranscribed.ThisisbecauseA. thelacoperonisswitchedoff.B. allolactosebindstothepromotergene.C. repressormoleculesbindtoallolactose.D. theregulatorygeneproducesmoreRNApolymerase.
Question 5Thebiochemicalpathwayofglycolysisinvolvesnineintermediatereactionsteps.Oneofthesestepsisrepresentedinthediagrambelow.
phosphofructokinase
fructose 6-phosphate fructose 1, 6-biphosphate
ATP ADP
Itiscorrecttostatethat,inthisreaction,phosphofructokinaseA. actsasacoenzyme.B. increasestherateofreaction.C. isthesubstrateforthereaction.D. releasesenergyintheformofADP.
2017BIOLOGYEXAM 4
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Use the following information to answer Questions 6–8.Hydrogenperoxideisatoxicby-productofmanybiochemicalreactions.Cellsbreakdownhydrogenperoxideintowaterandoxygengaswiththehelpoftheintracellularenzymecatalase.TheoptimumpHofcatalaseis7.ABiologystudentmeasuredtheactivityofcatalasebyrecordingthevolumeofoxygengasproducedfromthedecompositionofhydrogenperoxidewhenacatalasesuspensionwasaddedtoit.Thecatalasesuspensionwasmadefromground,rawpotatomixedwithdistilledwater.Thestudentperformedtwotestsandgraphedtheresults.
2.5
2.0
1.5
1.0
0.5
0.00 1 2 3
time (minutes)
4 5
volume ofoxygen gas
produced (cm3)Test 1
Test 2
Test1used5mLof3%hydrogenperoxidesolutionand0.5mLofcatalasesuspension,andwasconductedat20°CinabuffersolutionofpH7.Test2 wascarriedoutunderidenticalconditionstoTest1,exceptforonefactorthatthe studentchanged.
Question 6AnexplanationfortheresultsofTest2wouldbethatthestudentA. increasedtheconcentrationofcatalasebyaddinglesswatertothegroundpotato.B. increasedthetemperaturebyplacingthetesttubeinawaterbathsetat30°C.C. usedahydrogenperoxidesolutionwithahigherconcentration.D. addedacatalasesuspensionmadefromacookedpotatochip.
Question 7ThestudentthenperformedmoretestsbyvaryingthepHofthebuffersolution.ItisexpectedthatA. atpH6thereactionwillcease.B. atpH9thereactionwillbefaster.C. atpH2andpH10verylittleoxygenwillbeproduced.D. agreatervolumeofoxygenwillbeproducedeachtimethepHisincreased.
5 2017BIOLOGYEXAM
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Question 8Duringtheexperiment,thestudentmeasuredthevaryingpHlevelsusingadigitalpHmeter.ThestudentcalibratedthemeterusingapH7buffersolution.ThereasonthestudentcalibratedthepHmeterwastoA. ensurearandomerrorwouldnotinfluencetheresults.B. eliminatetheeffectofalluncontrolledvariables.C. enabletheuseoftheinstrumentwithprecision.D. allowthepHtobemeasuredaccurately.
Use the following information to answer Questions 9 and 10.Thefollowingisathree-dimensionaldiagramofanorganellefoundineukaryoticcells.
X
Y
Source:AlilaMedicalMedia/Shutterstock.com
Question 9TheregionlabelledXiscalledtheA. matrix.B. crista.C. innermembrane.D. intermembranespace.
Question 10ThestructurelabelledYiswhereA. glucoseentersglycolysis.B. NAD+isconvertedintoNADH.C. themajorityofATPisproducedinthecell.D. pyruvateisbrokendown,releasingcarbondioxide.
2017BIOLOGYEXAM 6
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Question 11Ananimalcellculturewasexposedtoradioactivelylabelledoxygen.Thecellswerethenmonitoredforthreeminutes.Afterthistime,theradioactivelylabelledoxygenatomswouldbepresentinwhichcellularchemical?A. adenosinetriphosphateB. carbondioxideC. glucoseD. water
Question 12EvidenceforthebacterialoriginofchloroplastsissupportedbyobservationsthatbothchloroplastsandbacteriaA. donotcontainribosomes.B. reproduceanddividebymitosis.C. haveasinglecircularchromosome.D. storechlorophyllintheiroutermembrane.
Use the following information to answer Questions 13 and 14.Thegraphbelowshowsthenetoutputofoxygeninspinachleavesaslightintensityisincreased.Temperatureiskeptconstantduringtheexperiment.
0 10 20 30 40 50
light intensity (arbitrary units, AU)
60 70 80 90
net output of oxygen(units of oxygen per gram
leaf tissue per minute)
0.2
0.1
0.0
–0.1
–0.2
R
T
S
P O
Question 13Whichoneofthefollowingconclusionscanbemadebasedonthegraph?A. AtpointTphotosynthesisisnolongeroccurring.B. Theoptimalleveloflightintensityforphotosynthesisis40AU.C. AtpointStheamountofoxygenoutputisathirdofthatatpointP.D. Below10AUoflightintensitytheaerobicrespirationrateisgreaterthanthephotosynthesisrate.
Question 14TherateofoxygenoutputremainsconstantbetweenpointsPandObecauseA. heathasdenaturedtheenzymesinvolvedinthephotosynthesisreactions.B. theconcentrationofavailablecarbondioxidelimitstherateofphotosynthesis.C. thelightintensityhasdamagedthechlorophyllmoleculespresentinthespinachchloroplasts.D. highlevelsofoxygenproducedatpointPhaveaccumulatedaroundthespinachleaves,resultinginnomore
oxygenbeingproduced.
7 2017BIOLOGYEXAM
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Question 15Avariegatedleaffromaplantisshownbelow.
K
M
Source:LeDo/Shutterstock.com
CellsfromsectionsMandKwereexaminedandsimplesketcheswereproduced.
A typical cell from section M A typical cell from section K
Fromthisinformation,itcanbeconcludedthatA. cellsinsectionKwouldbeunabletocarryoutaerobicrespiration.B. light-independentreactionsofphotosynthesiscanoccurincellsfromsectionK.C. thereischlorophyllpresentincellsfromsectionKbutnotincellsfromsectionM.D. glucosewouldbemanufacturedfromcarbondioxideandwaterincellsfromsectionMbutnotincellsfrom
sectionK.
Question 16AmoleculethattakespartinmanybiochemicalreactionsisNADP+.ItiscorrecttostatethatA. NADP+becomesNADHwhenitisloaded.B. NADP+hasahigherenergylevelwhenitisunloaded.C. energyisreleasedwhenNADP+isconvertedtoNADPH.D. NADP+carriesadditionalenergywhenprotonsandelectronsareaddedtoit.
2017BIOLOGYEXAM 8
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Use the following information to answer Questions 17 and 18.Thediagrambelowshowsasummaryofthestepsinaninsulinsignallingpathwaythatresultsinincreasedglucoseuptake.
insulin receptor
glucose molecules
insulin molecules bind
extracellular environment intracellular environment
secondary messenger moleculesand enzyme reactions
glucose-specific carriermolecules sent to plasmamembrane
insulinmolecules
Ascientiststudiedtheinsulinsignallingpathwaysoftwofemalepatients,EleniandShani.Eleni’spathwayisthesameasthatshowninthediagramabove.ThescientistdiscoveredthatthegenethatencodestheinsulinreceptorinShanihasamutation.InsulinmoleculescannotbindtoShani’sinsulinreceptors.
Question 17Fromthisinformation,itwouldbecorrecttoconcludethatA. insulinactsasahydrophilicsignallingmoleculeinEleniandShani.B. therewouldbemoreglucose-specificcarriermoleculesinShani’splasmamembranesthaninEleni’s.C. thebindingofinsulinmoleculestothereceptorinitiatestransductionandtheuptakeofglucoseinto
Eleni’scells.D. thepresenceofinsulininShaniwouldcauseanincreaseintheconcentrationofthesecondary
messengermolecules.
9 2017BIOLOGYEXAM
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Question 18ThescientistmeasuredthebloodglucoselevelsofbothEleniandShaniovera120-minuteperiodaftertheywereinjectedwiththehormoneinsulin.Thetablebelowshowstheresults.
Time (minutes)
Shani’s blood glucose level
(arbitrary units, AU)
Eleni’s blood glucose level
(arbitrary units, AU)
0 6.0 6.1
20 6.0 5.7
50 5.9 5.0
70 5.9 4.6
100 6.0 4.8
120 6.0 5.1
ThescientistwantedtocompareEleni’sandShani’sbloodglucoselevelsatthe90-minutemark.Whichoneofthefollowinggraphswouldallowthescientisttopredicttheirbloodglucoselevelsmostaccurately90minutesaftertheywereinjectedwithinsulin?
7
6
5
4
3
2
1
00 20 40 60
time (minutes)
80 100 120 140
bloodglucose
level(AU)
Shani Eleni
0 20 50 70time (minutes)
100 120
76543210
bloodglucose
level(AU)
Shani Eleni
Shani35.8 AU
of glucose
Eleni33.3 AU
of glucose
Shani Eleni
1201007050200
time(minutes)
0 2 4blood glucose level (AU)
6 8
A. B.
D.C.
2017BIOLOGYEXAM 10
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Question 19Thediagrambelowshowsthelocationofcancercellswithinatissue.
cancer cell
Source:inbevel/Shutterstock.com
Thenumberofcancercellswithinthetissueisrapidlyincreasing.ThisincreaseinthenumberofcancercellscanbeexplainedbyA. increasedcaspasefunctionwithineachofthecancercells.B. decreasedrateofapoptosisinthesurroundingnormalcells.C. reductioninsizeofthenucleiofcancercellscomparedtothoseofnormalcells.D. impairedsignallingfromdeathreceptorslocatedonthemembraneofthecancercells.
Question 20 Cytokinesareanexampleofasignallingmolecule.CytokinesA. arehydrophobic(lipid-based)hormones.B. producedbyacellcandiffusetoanearbytargetcell.C. crossasynapsebymovingdownaconcentrationgradient.D. aresecretedbyananimal,thenreleasedintotheairandproduceaneffectinanotheranimal.
11 2017BIOLOGYEXAM
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Question 21Myastheniagravisisanautoimmunediseaseinwhichautoantibodiesaffectthetransmissionofanerveimpulse.Inmyastheniagravis,communicationbetweenanerveandamuscleacrossaneuromuscularjunctionisdisrupted.Themusclecannotcontractwhenthiscommunicationisdisrupted.Thediagrambelowshowsaneuromuscularjunction.
axon of nerve cell
vesicle containing acetylcholine
acetylcholine receptor
membrane of muscle cell
Whichoneofthefollowingcouldexplainthefunctionalcauseofmyastheniagravis?A. Acetylcholineisahydrophobicmolecule.B. Acetylcholineisreleasedfromvesiclesbyendocytosis.C. Myastheniagravisautoantibodiesattachtoandblocktheacetylcholinereceptors.D. Signaltransductioninthemusclecellisamplifiedbyautoantibodiesproducedinpeoplewithmyastheniagravis.
Question 22Whichofthefollowingmatchesacellcorrectlywithitsroleinanimmuneresponse?
Cell Role
A. macrophage stimulatesinflammationbysecretinginterferon
B. dendriticcell presentsfragmentsofantigenstoThelpercells
C. mastcell engulfsbacteriaanddebris
D. neutrophil secretesantibodies
2017BIOLOGYEXAM 12
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Question 23
tonsils
spleen
lymph nodes
The human lymphatic system
Source:AlilaMedicalMedia/Shutterstock.com
Thelymphaticsystemincludesthelymphnodes,spleenandtonsils.IntheseparticularorgansA. clottingfactorsareinactivatedtohelpsealawound.B. clonalselectionandproliferationofBcellsoccurs.C. non-selfantigensareidentifiedbyredbloodcells.D. theinitialresponsetoanallergenistriggered.
Use the following information to answer Questions 24 and 25.Multiplesclerosis(MS)isanautoimmunedisease.InsufferersofMS,themyelincoatingofnervecellaxonsisdamaged.Thisdamageresultsinpoortransmissionofnervemessagesbetweenthebrain,thespinalcordandtherestofthebody.OneaspectofMSdiagnosisisimagingthebraintodetectvisibleareasofdemyelination,calledplaques.
Question 24 ResearchersinvestigatingMShaveanalysedvarioustissuesamplesfrompatients.InthesesamplestheywouldexpecttofindA. anabundanceofallergensinnervecells.B. cancercellsinMSplaquesinbraintissue.C. increasednumbersofThelpercellsinspinalfluid.D. anabsenceofTcytotoxiccellsinthespinalcordandbrain.
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Question 25ScientistsareinvestigatingfactorsthatincreasethelikelihoodofdevelopingMS.Recently,the‘hygienetheory’hasbeenconsideredapossiblefactor.Thistheoryproposesthat,ifachild’senvironmentisoverlyhygienicanddoesnotallowsufficientexposuretoawiderangeofnon-selfantigens,anoveractiveimmunesystemwillresultlaterinlife.Arecentstudytestedforthepresenceofantibodiesto thebacteria thatcausestomachulcers,Helicobacter pylori,inthebloodof550MSpatientsand299healthypeople.Bothgroupsofpeoplehadthesameproportionofeachgenderandwereofsimilarage.ExposuretoH. pyloriusuallyoccursbytheageoftwoyears.TheresultsoftheantibodytestingshowedthattherateofH. pyloriinfectionwas30%lowerinthewomenwithMSthaninthehealthywomenorhealthymen.ThefindingsofthisstudyareconsistentwiththesuggestionthatA. monoclonalantibodiescouldbeusedtotreatMS.B. malesareaffectedbyMS30%moreoftenthanfemales.C. sufferingfromastomachulcerisacommonsymptomofMS.D. infemaleschildhoodexposuretoH. pylorihelpstoprotectagainstMS.
Question 26 Adailybloodsamplewasobtainedfromanindividualwhoreceivedasinglevaccinationagainstaparticularstrainoftheinfluenzavirus. Theindividualhadnopriorexposuretothisstrainofinfluenza.Thegraphbelowshowstheconcentrationofantibodiespresentintheindividual’sbloodforthisstrainofinfluenzaoveraperiodof65days.
7
6
5
4
3
2
1
0
concentration ofinfluenza antibodies(arbitrary units, AU)
0 10 20 30
time (days)
40 50 60 70
Whichoneofthefollowingconclusionscanbemadeusingthisdata?A. MemoryBcellswereactivatedbyexposuretothesamestrainoftheinfluenzavirusonday22.B. Bplasmacellsspecifictothisstrainofinfluenzaweremostnumerousonday12.C. Herdimmunitytothisparticularstrainofinfluenzawasachievedbyday55.D. Thevaccinationcontainingweakenedinfluenzaantigensoccurredonday10.
2017BIOLOGYEXAM 14
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Use the following information to answer Questions 27 and 28.Thecodontablebelowcanbeusedtodeterminethesequenceofaminoacidscodedforbyanucleotidesequence.
1st position (5′ end)
2nd position 3rd position (3′ end) U C A G
U Phe Ser Tyr Cys UPhe Ser Tyr Cys CLeu Ser STOP STOP ALeu Ser STOP Trp G
C Leu Pro His Arg ULeu Pro His Arg CLeu Pro Gln Arg ALeu Pro Gln Arg G
A Ile Thr Asn Ser UIle Thr Asn Ser CIle Thr Lys Arg AMet Thr Lys Arg G
G Val Ala Asp Gly UVal Ala Asp Gly CVal Ala Glu Gly AVal Ala Glu Gly G
ThefollowingnucleotidesequenceoccursonthetemplatestrandofaDNAmolecule.
AAAGCTACCTATCGGTTA
Question 27Inamutation,theeighthnucleotideinthissequencewaschangedfromCtoT.Whatwouldbetheresultofthismutation?A. Thepeptidechainwouldbeshortened.B. ThethirdaminoacidwouldchangefromThrtoIle.C. ThefourthaminoacidwouldchangefromIletoTyr.D. Therewouldbenochangeintheaminoacidsequence.
Question 28Inadifferentmutation,aTwasinsertedafterthefourthnucleotideonthegiventemplatestrand.TheresultofthismutationwouldbethatA. allaminoacidsinthisentiresequencewouldchange.B. onlythefirstaminoacidinthesequencewouldchange.C. onlythesecondaminoacidinthesequencewouldchange.D. allaminoacidsafterthefirstinthesequencewouldchange.
15 2017BIOLOGYEXAM
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Question 29AnewbornbabywasdiagnosedwithPatausyndrome.Herkaryotypeshowedthreecopiesofchromosome13.ThisisanexampleofA. frameshiftmutation.B. blockmutation.C. aneuploidy.D. polyploidy.
Question 30Inthe18thcentury,farmerRobertBakewellseparatedlarge,fine-bonedsheepwithlong,shinywoolfromhisnativestocktointerbreedforfuturesheepflocks.ThisisanexampleofA. geneticfitness.B. naturalselection.C. selectivebreeding.D. allopatricspeciation.
Question 31 MastergenescontrolthejawformationofcichlidfishandthebeakformationofGalápagosfinchesbyA. controllingthetimingofproteinproductionatcrucialstagesofembryonicdevelopment.B. causingmutationsinthestructuralgenesforjawandbeakformation.C. bindingwithmRNA,preventinggeneexpression.D. cuttingDNAsequencesatspecificpoints.
2017BIOLOGYEXAM 16
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Question 32 Thephylogenetictreebelowrepresentsonemodeloftheorderandapproximatetimeofappearanceofthemajorgroupsoflivingorganisms,andincludesfourgroupsrepresentedbythelettersR,S,TandU.
SR T fungi U
first multicellular organism
oldest eukaryote fossil
origin of photosynthesis
oldest prokaryote fossil
millions ofyears ago
500
0
10001500200025003000
3500
Whichofthefollowingshowsthecorrectplacementoftheorganismsonthephylogenetictree?A. R–animals,S–plants,T–bacteria,U–protistsB. R–bacteria,S–protists,T–plants,U–animalsC. R–protists,S–animals,T–bacteria,U–plantsD. R–plants,S–animals,T–bacteria,U–protists
Question 33 MassextinctionsA. killallbutthemostprimitivespecies.B. arecausedbytheintroductionofcompetingspecies.C. arefollowedbyaperiodofrapiddivergentevolution.D. havebeencausedbycontinentaldriftandearthquakes.
Question 34Theprocessknownaspolymerasechainreaction(PCR)involvesrepeatedcyclesmadeupofseveralsteps.DuringPCRtheA. firststepineachcycleistoannealprimerstotheDNAatalowtemperature.B. temperaturemustbeloweredto37°Cbeforethebeginningofeachcycle.C. secondstepineachcycleistoheattheDNAtoahightemperature.D. finalstepofeachcycleinvolvestheuseofDNApolymerase.
17 2017BIOLOGYEXAM
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Question 35ModernAfricanHomo sapiensdonotcontainNeanderthalDNA.Modernnon-AfricanH. sapienscontainasmallpercentageofNeanderthalDNAbecauseofinterbreedingbetweenNeanderthalsandH. sapiens.Thisinterbreedingisthoughttohaveoccurredwithinthetimeperiod65000to47000yearsago.ArecentstudyhasfoundH. sapiensDNAinthegenomesof100000-year-oldNeanderthalremains.Fromthisnewdiscovery,itwouldbereasonabletoconcludethatA. modernAfricansarethedescendantsofNeanderthals.B. therewasanearlymigrationofH. sapiensoutofAfricabefore100000yearsago.C. theancestorsofmodernAfricansmigratedfromEuropetoAfricabetween65000and47000yearsago.D. approximately100000yearsago,NeanderthalsbredwithH. sapiensinAfricabeforetheNeanderthalsspreadto
therestoftheworld.
Question 36Inrecentyears,scientistshavediscoveredthatNeanderthalstookcareoftheirelderlyrelatives,usedburialritualsfortheirdeadandgavesymbolicmeaningtonaturalobjects.StudieshavealsoshownthatNeanderthalsusedcomplexmethodstoobtainsharpstoneimplementsandproducegluestoattachsharpstonestospears.ThesediscoveriessuggestthatNeanderthalsA. hadbiggerbrainsthanpreviouslythought.B. hadahighlydevelopedculture.C. livedasolitarylifestyle.D. usedawrittenlanguage.
Question 37Yellowfeverisaviraldiseasethatistransmittedprimarilybymosquitoes.AnoutbreakofyellowfeverwasreportedtohaveoccurredinanareaofBrazilinJanuary2017.ThisoutbreakwasreportedtobespreadingtootherareaswithinBrazil.Whichoneofthefollowingisacorrectstatementaboutthisoutbreakofyellowfever?A. Thisoutbreakofyellowfeverisconsideredtobeapandemic.B. InfectedindividualswhotraveltootherareasofBrazilwillnotincreasethespreadofthedisease.C. Thisoutbreakofyellowfeverisoccurringinpopulationswithhighvaccinationratesforyellowfever.D. Eliminationofmosquitobreedingsitesinareaswithyellowfeverwillreducethenumberofindividuals
affected.
2017BIOLOGYEXAM 18
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Question 38 ThediagrambelowrepresentsaDNAmoleculeandthepositionoftherecognitionsitesfortherestrictionenzymesBamHI,EcoRI,HaeIIIandSalI.
BamHI EcoRI HaeIII EcoRI SalI EcoRI BamHI SalIDNAmolecule
AlsoshownisadiagramofanelectrophoresisgelinwhichthelanesR,S,TandUshowtheseparationofDNAsegmentsresultingfromdigestionofthemoleculewithoneoftherestrictionenzymes.
R S T Uelectrophoresis gel
WhichofthefollowingshowsthecorrectmatchbetweenthelaneandtherestrictionenzymeusedtodigesttheDNAmolecule?
R S T U
A. SalI EcoRI HaeIII BamHI
B. EcoRI BamHI HaeIII SalI
C. EcoRI BamHI SalI HaeIII
D. HaeIII SalI BamHI EcoRI
19 2017BIOLOGYEXAM
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Question 39DNAprofiling,usingshorttandemrepeats(STR)withinaperson’sDNA,helpstodeterminethegeneticrelationshipbetweenindividuals.DNAprofilesbasedonfourSTRsforfiveindividualsareshownbelow.Theresultsofagenderidentifierarealsoshown.
STR Individual 1 Individual 2 Individual 3 Individual 4 Individual 5
CSF1PO 7,14 7,11 8,13 7,14 7,14
TPOX 6,10 10,12 6,9 10,12 10,10
D21S11 27,30 29,32 27,27 29,30 27,28
D8S1179 9,11 12,13 17,17 11,12 9,11
Individual 1 Individual 2 Individual 3 Individual 4 Individual 5
Gender identifier male female female male male
Whichoneofthefollowingconclusionscanbemadeusingtheinformationgiven?A. Individual4isthefatherofIndividual5.B. Individual3isthemotherofIndividual4.C. Individual5couldbethechildofIndividual1andIndividual3.D. TheparentsofIndividual4couldbeIndividual1andIndividual2.
Question 40Plantvirusesareamajorproblemforfarmersgrowingcrops.Aparticularplantviruscaninfectmanydifferentplantspecies.Scientistsaretriallingaspraytreatmentontobaccocrops.ThetreatmentdoesnotaltertheDNAofthetobaccoplants.Duringthistreatment,tobaccoplantsaresprayedwithclaynanoparticlescontainingdouble-strandedRNA(dsRNA).ThedsRNAreleasedfromeachoftheclaynanoparticlesenterstheplantcells.InsideeachcellthedsRNAsilencesagenefromthevirusbycausingviralRNAtobreakdown.InthistechniquetheA. dsRNAwouldhaveanucleotidesequencecomplementarytoasectionofDNAnucleotidesinthetobacco
plants.B. dsRNAwouldsilenceagenefromthevirusbyinitiatingchangesthatpreventtranslationoftheviralgene.C. spraytreatmentwouldbeeffectiveonlyontobaccoplantsandnotonotherplantspecies.D. sprayedtobaccoplantswouldberegardedastransgenicorganisms.
2017BIOLOGYEXAM 20
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SECTION B – Question 1–continued
Question 1 (11marks)Considerthediagramofaplasmamembranebelow.
Molecule U
Molecule R
Molecule S Molecule T
intracellular environment
extracellular environment
Source:JamiliaMarini/Shutterstock.com
a. i. Thereisahigherconcentrationofasmallhydrophobicmoleculeintheextracellularenvironmentthanintheintracellularenvironment.
Drawonearrowonthediagramabovetoshowthepathwaytakenbythesmallhydrophobicmoleculeacrosstheplasmamembrane. 1mark
ii. Justifythepathwayyouhavedrawn. 2marks
SECTION B
Instructions for Section BAnswerallquestionsinthespacesprovided.Writeusingblueorblackpen.Unlessotherwiseindicated,thediagramsinthisbookarenot drawntoscale.
21 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
b. i. Oneofthemolecules–MoleculeR,MoleculeS,MoleculeTorMoleculeU–containsmanyaminoacids.
Circlethemoleculebelowthatcontainsmanyaminoacids. 1mark
MoleculeR MoleculeS MoleculeT MoleculeU
ii. Nametheorganellewithinacellwherethemoleculecircledinpart b.i. issynthesised. 1mark
iii. Describethechemicalreactionthattakesplacetojointogethertheaminoacidsofthismolecule. 3marks
c. Differentcellswithinanorganismhavedifferentproteins.Insomecasesdifferentproteinscanbecodedforbythesamegene.
Explainhowtheexpressionofasinglegenecanleadtotheproductionofdifferentproteins. 3marks
2017BIOLOGYEXAM 22
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SECTION B – Question 2–continued
Question 2 (5marks)Althoughplantshavenoimmunesystems,theydohavemanychemicalandphysicalmethodsofdefenceagainstpathogensandattacksbyinsects.
a. Describeoneexampleofaphysicalmethodofdefenceinaplant. 2marks
Whiteclover(Trifolium repens)reproducesasexuallyfromarunnerthatgrowsalongthesoilsurface.Theconnectednewplantsarecalledramets.Thewhiteclover plantinthediagrambelowisproducingrametsinthedirectionlefttoright.Thefullygrownrametsarenumbered1to7,fromtheyoungestramettotheoldestramet.
7 6 5 4 3 2 1
youngest fully grownramet
newly developingrametdirection of runnergrowth
oldestramet
leaf surface
Source:adaptedfromSGómez,YOnoda,VOssipovandJFStuefer,‘Systemicinducedresistance: Arisk-spreadingstrategyinclonalplantnetworks?’,The New Phytologist, vol.179no.4(September2008),p.1144
ScientistshypothesisedthatwhenT. repensrametsaredamagedbycaterpillarsofSpodoptera exigua, thedamagedrametsstimulateotherrametstodefendthemselvesagainstattackbythecaterpillars.Thescientistsconductedanexperimenttotesttheirhypothesis.Theexperimentusedtwogeneticallyidenticalrunners,AandB.Themethodisoutlinedintheflowchartonpage23.
23 2017BIOLOGYEXAM
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SECTION B – Question 2–continuedTURN OVER
Ramets 6 and 7 were each enclosed in aseparate, plastic mesh cage for four days.
Runner A Runner B
Ramets 6 and 7 were each enclosed in a separate, plastic mesh cage. Each cagecontained one caterpillar. The cages were left on for four days, during which time 30% of leaf surfaces were eaten.
Ramets 1 and 5 were cut off Runner A and placed into a Petri dish. A caterpillar wasreleased midway between the two ramets andallowed to feed freely.
Ramets 1 and 5 were cut off Runner B and placed into a Petri dish. A caterpillar wasreleased midway between the two ramets andallowed to feed freely.
matureRamet 5
youngRamet 1
caterpillarreleased
matureRamet 5
young Ramet 1
caterpillarreleased
After two days, the leaf surface area eaten on each ramet was measured.
Stage 1 – Leaf damage preparation
Stage 2 – Food choice test
b. WhatwastheroleoftheRunnerAramets? 1mark
2017BIOLOGYEXAM 24
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SECTION B – continued
Theexperimentwasrepeated40times.TheaverageresultsobtainedafterStage2areshowninthegraphbelow.
0.70.60.50.40.30.20.10.0
average leafsurface area eaten
(cm2)
young mature
Runner A ramets
young mature
Runner B ramets
White clover (T. repens) leaf surface area eatenby caterpillars (S. exigua) in food choice test (n = 40)
Data:SGómez,YOnoda,VOssipovandJFStuefer,‘Systemicinducedresistance: Arisk-spreadingstrategyinclonalplantnetworks?’,
The New Phytologist, vol.179no.4(September2008)
c. Referringtothedata,comparetheaverageleafsurfaceareaofyoungrametseatenbythecaterpillarsinRunnerAandRunnerB. 1mark
d. Aftertheexperiments,thecontentsoftheleaveswereanalysed.SignificantlyhigherquantitiesofphenolicacidwerefoundintheyoungrametsfromRunnerB.Phenolicacidactsasasignallingmolecule.
ItwasnoticedthatthecaterpillarspreferredtoeatthematureleavesinRunnerB.
Suggestaneffectofthesignallingmoleculeonthecellsoftheyoungleavesthatwouldaccountforthecaterpillars’preferenceforeatingthematureleavesinRunnerB. 1mark
25 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
Question 3 (5marks)RationaldrugdesignwasusedbyscientiststodevelopthedrugRelenza.
a. Whatismeantbytheterm‘rationaldrugdesign’? 2marks
b. ManypeopleinAustraliahavehighbloodcholesterollevels.Highbloodcholesterollevelsarelinkedtocoronaryheartdisease.Cholesterolisproducedbyaseriesofchemicalreactions.Oneofthereactionsintheseriesisshownbelow.
HMG-CoA reductase
HMG-CoA mevalonate
Lovastatinisusedtotreathighbloodcholesterol.Whenadministered,thelovastatinisconvertedtoanactiveformthatisareversiblecompetitiveinhibitorofHMG-CoAreductase.
i. Whatdoesthissuggestaboutthestructureoftheactiveformoflovastatin? 1mark
ii. Tosuccessfullytreathighlevelsofcholesterol,lovastatinmustbetakeneverydayatregulartimeintervals.
Consideringthemodeofactionoflovastatin,whyisitimportanttopreventthebloodconcentrationoflovastatinfrombecomingtoolow? 2marks
2017BIOLOGYEXAM 26
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SECTION B – Question 4–continued
Question 4 (11marks)Australianmarsupials,suchaswallabies,kangaroos,wombatsandkoalas,givebirthtoveryundevelopedyoungcalledjoeys.Whenajoeyentersthemother’spouch,itisatastageequivalenttoaseven-week-oldhumanfetus.Itspendsmanyweeksinthepouchfeedingonmilkproducedbymammaryglands.Althoughthepouchprovidesprotectionfrompredators,itisneithersealednorsterile.
a. i. Whatismeantbytheterm‘sterile’inthecontextgiven? 1mark
ii. Considerahospitalenvironment.Givetwoexamplesofhowsterileconditionscanbeachievedinahospital. 2marks
Thejoey’sprimaryimmunetissue(inthebonemarrowandthymus)doesnotmatureuntil30daysafterbirthanditshumoralimmunitydoesnotfunctioneffectivelyuntil90daysafterbirth.Biologistshaveanalysedmilksamplesfromseveralmarsupialspeciesandfoundthattheycontainvariousantibodies.Someoftheantibodiesinthemother’smilkremaininthejoey’sgut,whileotherscrossthegutwallandenterthejoey’sbloodstream.
b. Describeatamolecularlevelhowantibodiesperformtheirfunction. 2marks
27 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
c. Namethetypeofimmunitythatthejoeyobtainsfromtheantibodiesinthemilkandexplainhowthisformofimmunityisbeneficialtothejoey. 3marks
Scientistshavefoundthatthemilkofthetammarwallaby(Macropus eugenii)containshighlevelsofpeptideswithantibioticproperties,aswellaslysozyme,complementproteins,cytokinesandvenominhibitors.
d. i. Namethepartoftheimmunesystemtowhichthesepeptidesandtheotherlistedchemicalsbelong. 1mark
ii. Circleoneofthechemicalsbelow,foundintammarwallabymilk,anddescribeitsroleinprotectingthejoeyagainstpathogens. 1mark
lysozyme complementproteins cytokines venominhibitors
Role
e. Scientiststestedthetammarwallabymilkpeptidesandfoundthemtobe10timesmoreeffectivethanantibioticssuchastetracyclineandampicillin,whicharecommonlyusedtofighthumandiseases.Thescientistsarekeentofindapharmaceuticalcompanythatwillsupportfurthertestinganddevelopmentofthesepeptideswithantibioticproperties.
Suggestwhatthescientistswouldhopetoachieveasaresultoffurthertestingofthesepeptideswithantibioticproperties. 1mark
2017BIOLOGYEXAM 28
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SECTION B – continued
Question 5 (6marks) Therufousbristlebird(Dasyornis broadbenti)isaground-dwellingsongbird.Therufousbristlebirdisfoundingardensnearthick,naturalvegetationandbuildsnestsinshrubsclosetotheground.Therufousbristlebirdfeedsonground-dwellinginvertebrates.Itisaweakflyerandisslowtogobacktoareasfromwhichithasbeenpreviouslyeliminated.Twodistinctpopulationsofrufousbristlebird existinVictoria.ThedistributionofeachpopulationisshownonthemapofVictoriabelow.ThedistancebetweenPopulationAandPopulationBisover200km.
Population A
Population B
Source:Flora & Fauna Guarantee Action Statement,1993,no.49; ©TheStateofVictoria,DepartmentofSustainabilityandEnvironment,2003
a. Definetheterm‘geneflow’andexplainwhethergeneflowislikelytooccurbetweenthesetwopopulations. 3marks
b. BothoftherufousbristlebirdpopulationsinVictoriaaresmall.
Referringtothetheoryofnaturalselection,explainwhytherufousbristlebirdisatriskofextinction. 3marks
29 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
Question 6 (5marks)DNAhybridisationisamoleculartechniqueusedtodeterminetheevolutionaryrelationshipsbetweenspecies.DNAisextractedfromeachspeciesandcutintofragments.
a. OutlinethestepsinvolvedintheDNAhybridisationtechniquefollowingtheextractionandcutting ofDNA. 3marks
b. HowdoesthetechniqueofDNAhybridisationenablescientiststodeterminetheevolutionaryrelationshipsbetweenspecies? 2marks
2017BIOLOGYEXAM 30
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SECTION B – continued
Question 7 (3marks) In2013,about1500fossilbonesofahomininspecieswerefoundinacaveinSouthAfrica.Fromthesebones,scientistshavemanagedtoconstructanalmostcompleteskeleton.ThefossilboneshavesomefeaturesincommonwiththoseofthegenusAustralopithecus;however,theyhaveenoughsimilaritiestothegenusHomothatscientistshaveclassifiedthefossilskeletonasbelongingtoanewspecies,Homo naledi.
a. WhataretwofeaturesthatthefossilskeletonwouldneedtohaveinordertobeclassifiedinthegenusHomoandnotinthegenusAustralopithecus? 2marks
FindingouttheageoftheseH.naledifossilshasbeenbothdifficultandcontroversial.Agroupofscientistsclaimsthattheageofthefossilsismorethan2millionyearsandsuggeststhatH. naledi mightbea‘link’betweenAustralopithecusandHomo.AsecondgroupofscientistshascalculatedtheageoftheH. naledifossilstobeonlyabout900000yearsandclaimsthatH. naledi cannotbethe‘link’betweenAustralopithecusandHomo.ThediagrambelowindicatesthetimeperiodsfordifferentAustralopithecus andHomospecies.
Australopithecus anamensis
Australopithecus africanus
Australopithecus afarensis
Australopithecus garhi
Homo habilis
Homo rudolfensis
Homo ergaster
Homo erectus
Homo neanderthalensis
Homo sapiens
Homo denisova
Homo floresiensis
8 7 6 5 4million years ago
3 2 1 0
b. IfthesecondgroupofscientistshascorrectlydatedtheH. naledifossils,whatevidencefromthediagramabovesupportsthisgroup’sclaimthatH. naledicannotbethe‘link’betweenAustralopithecus andHomo? 1mark
31 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
Question 8 (4marks)InAustralia,geneticscreeningiscarriedoutonnewbornbabies.
a. Explainwhyitisimportanttohaveageneticscreeningprogramfornewbornbabies. 2marks
b. Statetwoethicalimplicationsofthegeneticscreeningofnewbornbabies. 2marks
2017BIOLOGYEXAM 32
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SECTION B – Question 9–continued
Question 9 (7marks) Scientistsuserecombinantbacterialplasmidsasvectorstotransformbacteriaforarangeofpurposesinresearchandbiotechnology.
a. Whatismeantbytheterm‘vector’inthecontextgiven? 1mark
AparticularbacterialplasmidcontainsrecognitionsitesfortherestrictionenzymesEcoRI,HindIIIandBamHI,alongwithtwoantibiotic-resistantgenes,ampicillinresistance(amp)andtetracyclineresistance(tcl),andanoriginofreplication(ORI).Thediagrambelowshowsthepositionsoftheserecognitionsitesandantibiotic-resistantgenesaswellasthepositionoftheoriginofreplicationwithinthisplasmid.
EcoRIHindIII
BamHI
amp tcl
ORI
Onepurposeofusingrecombinantbacterialplasmidsistoproducebacteriacapableofsynthesisinghumanprotein.
33 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
b. TherestrictionenzymeBamHIwasusedtohelpinsertagenecodingforahumanproteinintothisplasmid.
i. DescribehowrestrictionenzymessuchasBamHIareusedtohelpinsertagenecodingforahumanproteinintothisplasmid. 2marks
ii. DrawandlabeladiagraminthespacebelowtoshowthepositionofthehumangeneinthisplasmidwhenBamHIisused.IncludethepositionoftherecognitionsitesfortherestrictionenzymesEcoRI,HindIIIandBamHIontheplasmid. 1mark
c. Afterthescientistshadcarriedoutthestepsrequiredtomakeplasmidswiththeinsertedhumangene,theseplasmidsweremixedwithacultureofbacteria.Thismixturewastreatedsothattheseplasmidswouldmoveintothebacterialcells.Notallbacteriatookuptheseplasmids.
Explainhowscientistsuseantibioticstoidentifywhichofthebacterialcellshavebeensuccessfullytransformedwithplasmidscarryingthehumangene. 3marks
2017BIOLOGYEXAM 34
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SECTION B – Question 10–continued
Question 10 (9marks)
Aboriginal Australians co-existed with the megafauna for at least 17 000 yearsAustraliawasoncehometogiantreptiles,marsupialsandbirdsknownasmegafauna.ManyresearchershavesuggestedarapidextinctionmodeltoaccountfortheextinctionofmegafaunathoughttohaveoccurredsoonafterthearrivaloftheFirstAustralians1.TheFirstAustraliansregularlyburntthelandscapetoencouragenewgrowthforfoodandtoattractpreyforhunting.PerhapsthisburningdramaticallyalteredancientAustralia’secology.Onespecies,thegiantflightlessbirdGenyornis newtoni,wasshowntohavesuccumbedtosignificanthabitatchangeandexcessivehunting.Incontrast,otherevidenceshowsnorecordoffire-sensitiveplantsgoingthroughgeneticbottlenecksasaresultofsignificantburningevents.Furthermore,evidencesuggeststhatfortensofthousandsofyears,Aboriginalpopulationswerenotthatlarge.Someresearchershavearguedthatitispossiblemanyofthe45orsomegafaunaspeciesthoughttohavebecomeextinctmayhaveinfactbecomeextincttensofthousandsofyearsbeforetheFirstAustraliansarrived.IfitcanbeshownthatmegafaunadisappearedsoonafterthearrivaloftheFirstAustralians,thenthereissupportfortherapidextinctionmodel.Ontheotherhand,proofthatmegafaunaandpeopleco-existedsuggeststhatotherexplanationsfortheirextinctionneedtobeproposed.RecentdatingofaspecimenofZygomaturus trilobus,alargewombat-likemarsupial,showedthatthespecimendiedaround33000yearsago.Thisevidencesuggeststhatpeopleandmegafaunaco-existedforatleast17000years.ItisnowpossiblethattherapidextinctionmodelneedstobeabandonedandresearchersneedtostarttountanglehowclimatemayhaveplayedaroleorhowchangesinAboriginalpopulationnumbersmayhaveimpactedontheecologyofthemegafauna.
Source:extractadaptedfromMWestaway(GriffithUniversity),JOlley(GriffithUniversity),RGrun(GriffithUniversity), ‘AboriginalAustraliansco-existedwiththemegafaunaforatleast17000years’,TheConversationwebsite,12January2017,
<https://theconversation.com/au>
1First Australians–theancestorsofAboriginalAustralians
35 2017BIOLOGYEXAM
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SECTION B – continuedTURN OVER
a. Usingtheinformationinthetext,explainhowtherapidextinctionmodelmayaccountfortheextinctionofAustralia’smegafauna. 3marks
b. Completethefollowingtablebyidentifyingthreepiecesofevidenceinthetextthatcastdoubtontherapidextinctionmodel.Justifyhoweachpieceofevidencecanbeusedtorejecttherapidextinctionmodel. 6marks
Evidence Justification
1.
2.
3.
2017BIOLOGYEXAM 36
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SECTION B – Question 11–continued
Question 11 (14marks)Matthewinvestigatedhowchangesinenvironmentaltemperatureaffectedoxygen(O2)andcarbondioxide(CO2)levelsintheairaroundacockroach.Heusedthreedigitalprobeslinkedtoacomputer,aclosedanimalchamberandaheatlampintheexperimentalset-upshown.
heat lamp
computer
CO2 probe O2 probe
temperatureprobe (°C)
a. NamethecellularprocessbeinginvestigatedinMatthew’sexperiment. 1mark
b. Identifythe 2marks• dependentvariables
• independentvariable.
Beforeplacingthecockroachinthechamber,Matthewdecidedtomeasurethetemperature,andcarbondioxideandoxygenlevelsforfourminutes.Thefollowingresultswererecorded.
Time (minutes) CO2 (%) O2 (%) Temperature (°C)
0 0.04 22.3 29.5
1 0.04 22.1 29.8
2 0.04 22.0 30.0
3 0.04 22.0 30.0
4 0.04 22.0 30.0
37 2017BIOLOGYEXAM
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SECTION B – Question 11–continuedTURN OVER
c. ExplainwhyMatthewrecordedthedataforfourminutesandnotjustoneminute. 1mark
Aftertheinitialfour-minuteperiod,Matthewquicklyplacedthecockroachinthechamberandbeganrecordingthedatafromthedigitalprobes.After10minutes,heplacedicepacksaroundthesidesoftheanimalchambertoslowlybringthetemperatureofthechamberdownto10°C.Herecordedthedatausingthedigitalprobesforafurther20minutes.Herepeatedtheexperimentonceeverydayforthenextsixdayswiththesamecockroach.Atalltimes,hetookcaretoensurethatthecockroachshowednosignsofstress.
d. Otherthanrepeatingtheentireexperiment,identifytwocontrolmeasuresMatthewshouldhaveincludedinhisexperimentaldesign.Explainhoweachofthesecontrolmeasurescouldaffecttheresultsifnotkeptconstant. 4marks
2017BIOLOGYEXAM 38
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SECTION B – Question 11–continued
Matthewconstructedthefollowinggraphsfromtheaveragedresultsofthesevenexperiments.
35
30
25
20temperature (°C)
15
10
5
00 5 10 15
time (minutes)
20 25 30
25
20
oxygen (%)15
10
5
00 5 10 15
time (minutes)
20 25 30
0.100.090.080.070.060.05
carbon dioxide (%)
0.040.030.020.010.00
0 5 10 15
time (minutes)
20 25 30
39 2017BIOLOGYEXAM
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END OF QUESTION AND ANSWER BOOK
e. i. Usingthegraphicaldata,describethechangesinthelevelsofcarbondioxideandoxygenwhenthetemperatureinthechamberwaskeptconstantcomparedtowhenthetemperaturewasdecreasing. 2marks
ii. WhatconclusiondoyouthinkMatthewcandrawfromhisinvestigation?Youshouldrefertoeachofthefollowinginyourresponse:• thecellularprocessnamedinpart a.• thevariablesidentifiedinpart b.• theevidencecollectedduringMatthew’sexperiments 4marks
