BIOLOGYWritten examination
Friday 2 June 2017 Reading time: 10.00 am to 10.15 am (15 minutes) Writing time: 10.15 am to 12.45 pm (2 hours 30 minutes)
QUESTION AND ANSWER BOOK
Structure of bookSection Number of
questionsNumber of questions
to be answeredNumber of
marksA 40 40 40B 11 11 70
Total 110
• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpenersandrulers.
• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.
• Nocalculatorisallowedinthisexamination.
Materials supplied• Questionandanswerbookof36 pages.• Answersheetformultiple-choicequestions.
Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname andstudent numberasprintedonyouranswersheetformultiple-choice
questionsarecorrect, andsignyournameinthespaceprovidedtoverifythis.• 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(NHT) 2
SECTION A – continued
Question 1CellulosebelongstothegroupofbiomacromoleculescalledA. triglycerides.B. polypeptides.C. nucleicacids.D. polysaccharides.
Question 2Whichoneofthefollowingstatementsaboutcelluloseistrue?A. Itiscomposedofthesamemonomerasproteins.B. Itdoesnotprovidestabilitytotheplantcell.C. Itissynthesisedviacondensationreactions.D. Ithasexactlythesamestructureasstarch.
Question 3 Bothplantandanimalcellshaveplasmamembranes.Considerthestructureoftheplasmamembranesofplantcells.TheplasmamembranesofplantcellsA. haveidenticalproteinstotheplasmamembranesofanimalcells.B. haveaphospholipidbilayerstructuresimilartoanimalcells.C. aremadeupmainlyoffatsandstarch.D. containmainlycellulose.
SECTION A – Multiple-choice questions
Instructions for Section AAnswerall questionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrect forthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.
3 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Question 4Sixmoleculesthatformpartoftheplasmamembraneofananimalcellareshownbelow.
S
R
Whichoneofthefollowingstatementsistrue?A. TheRportionsofthemoleculesareontheoutersurfaceofthecell.B. TheSportionsofthemoleculesrepresentthehydrophilicphosphateheads.C. BoththeSandRportionsofthemoleculesremainfixedinpositionwithinthemembrane.D. TheSandRportionsofthemoleculestogetherallowfortheeasytransportofglucose.
Question 5Thegraphbelowshowsthegrowthrateofdifferenttypesofbacteriawhenthebacteriaareexposedtovaryingconcentrationsofatmosphericoxygen.
100
50
relativegrowth rateof bacteria(per cent)
0 5 10 15 20concentration of oxygen
(per cent of atmosphere)
Bacteria RBacteria SBacteria TBacteria U
Key
Basedonyourknowledgeandtheinformationinthegraph,whichoneofthefollowingstatementsistrue?A. BacteriaRareunabletocarryoutanaerobicrespiration.B. BacteriaUarepoisonedbyahighconcentrationofoxygen.C. BacteriaSareabletocarryoutbothaerobicandanaerobicrespiration.D. BacteriaTareunabletocarryoutbothaerobicandanaerobicrespiration.
2017BIOLOGYEXAM(NHT) 4
SECTION A – continued
Question 6Whichoneofthefollowingdiagramsisacorrectrepresentationofthewaytheionsmoveacrossaplasmamembrane?
A.
C.
B.
D.
ions on either side of plasma membraneion pumpion channel
Key
RS
R Splasma membrane
plasma membrane
plasma membrane
plasma membrane
R S
R S R S
ADP + PiATP ADP + PiATP
ADP + PiATP
ADP + PiATP
ADP + PiATP
Question 7Whenahydrophilicsignallingmoleculereachesatargetcell,whichsequenceofstepsoccurs?A. bindingtoglycolipidoncellsurface,transduction,responseB. bindingtoproteinreceptoroncellsurface,transduction,responseC. bindingtocytoplasmicreceptormolecule,transduction,responseD. bindingtoendoplasmicreticulumreceptormolecule,stimulationofgeneregulator,transduction,
response
Question 8 Whenratsarestressed,theyreleaseachemicalthatappearstocauseotherratsnearbytobecomeanxious.ThischemicalisaA. neurotransmitter.B. pheromone.C. pathogen.D. enzyme.
5 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Question 9 Totestthehypothesisthatauxinproducedintheapicaltipinhibitsthelateralgrowthofbranchesinpeas, astudentsetupanexperimentasshowninthediagrambelow.
gel containing auxin applied tocut end
decapitation –apical tip removed
normal pea plant
decapitation –apical tip removed
normal pea plant
lateral branch
10 days
10 days
Treatment 1
Treatment 2
apicaltip
apicaltip
WhichoneofthefollowingisacontrolforTreatment2?
A. apeaplantwiththebottomleavesremoved
B. anintactpeaplantwithmanyleaves
C. adecapitatedpeaplantwithafoilcapplacedonthecutend foil cap coveringcut end
D. adecapitatedpeaplanttowhichagelcontainingnoauxinisappliedtothecutend
gel containingno auxin appliedto cut end
2017BIOLOGYEXAM(NHT) 6
SECTION A – continued
Question 10Whichoneofthefollowingstatementsaboutthetransmissionofanervesignalistrue?A. AnerveimpulseisfacilitatedbyNa+/K+pumpsonthemembraneoftheneuron.B. Calciumionsareinvolvedinthetransmissionoftheimpulsealongtheneuron.C. Thegreaterthestimulus,thegreaterthesizeofthenerveimpulse.D. Neurotransmittersareactivelytransportedacrossthesynapse.
Question 11WhenapoptosisisinitiatedbyDNAdamageinacellA. theplasmamembraneruptures,releasingthecellcontents.B. acascadeofreactionsoccursinthecytoplasm.C. allenzymeactivitywithinthecellisinhibited.D. uncontrolledreplicationofthecelloccurs.
Question 12Thelymphaticsystemplaysanimportantroleindefendingthehumanbodyagainstdisease.Whichoneofthefollowingistrueofthelymphaticsystem?A. Lymphnodesprovideanaturalbarrieragainsttheentryofpathogensintotheinternalenvironment.B. Lymphcontainshydrochloricacid,whichkillsmanybacteria.C. Cellswithinthelymphnodesdetectantigens.D. Lymphcontainsmucustotrapbacteria.
7 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Use the following information to answer Questions 13 and 14.Inextremelyrarecases,injectionofaninfluenzavaccinemaycauseanallergicreaction,whichusuallyoccurswithinafewhoursofthevaccinebeingadministered.Theflowchartbelowoutlinesthekeystagesinanallergicresponse.
Step Pbody tissues
exposed to allergen
Step QB cells stimulated
Step RB plasma cellsproduce IgEantibodies
Step S
Step Vsigns of allergy, for
example, runny nose
?
Step Useveral physiologicaleffects, for example,
increased mucussecretion
Step Tcells release
histamine
Question 13WhichoneofthefollowingstatementsbestsummarisesStepS?A. CytotoxicTcellsareactivated.B. SecretedIgEantibodiesbindtomastcells.C. ComplementproteinsstimulateT-helpercells.D. SecretedIgEantibodiesattachtomacrophages.
Question 14AnotherexampleofaphysiologicaleffectatStepUandaresultingsignofallergyatStepVcouldbeA. capillariesbecomingpermeableandleaky,causingswelling.B. increasingnumbersofphagocytes,leadingtorednessoftheskin.C. vasodilationoftheskinbloodvessels,leadingtopalenessoftheskin.D. relaxationofthesmoothmusclesinlungtubules,causingbreathingdifficulties.
Question 15Guillain-Barrésyndromeisahumanautoimmunediseasethataffectsthenervoussystem.ThereisnocureforGuillain-Barrésyndrome,butresearchershavedevelopedatreatmentthatcanreducethesymptomsofGuillain-Barrésyndromeinpatients.WhichoneofthefollowingcouldbeausefultreatmentforGuillain-Barrésyndrome?A. vaccinationwithanattenuatedformoftheGuillain-BarrépathogeninordertodevelopBmemorycellsB. injectionofphagocyticcellsthathavebeendevelopedtorecogniseanddestroytheGuillain-Barré
pathogenC. repeatedremovalofthepatient’sbloodandfilteringofantibodiesbeforereturningthebloodtothe
patient’sbodyD. administrationofhigher-than-normaldosesoftheantibioticpenicillinwithinthefirst48hoursof
symptomsofGuillain-Barrésyndromebeingnoticed
2017BIOLOGYEXAM(NHT) 8
SECTION A – continued
Question 16 CanolaisaneconomicallyimportantcropplantinAustralia.Pathogensthatreducecanolaproductionareaconcerntogrowers.Onesignificantdiseaseisblackleg,causedbythefungus Leptosphaeria maculans. A detailedexaminationofinfectedcanolastemshasshownthepresenceofthefungus.ThestructureoftheL. maculanspathogenconsistsofA. asingleproteinmolecule.B. cellswithoutDNAmolecules.C. aproteincoatenclosingRNAmolecules.D. cellswithacellwallandanuclearmembrane.
Question 17Scientistsperformedanexperimentinwhichtheyobservedtheinteractionofredbloodcells(RBCs),antibodiesandtheinfluenzavirus.Differentcombinationsoftheseweremixedtogetherinsmallcontainerscalledwells.Twodifferentantibodiesweretested.Theresultsareshownbelow.
Components added to the well
Interaction Observation
Well A RBCs noclumpingofredbloodcells
Well B
+
virus RBCs clumpingofredbloodcells
Well C virus
+
+
Antibody type 1
RBCs
noclumpingofredbloodcells
Well D virus
+
+
Antibody type 2
RBCs
clumpingofredbloodcells
Source:adaptedfromCentersforDiseaseControlandPrevention(www.cdc.gov/)
Whichoneofthefollowingwouldbeareasonableconclusiontodraw?A. Antibodytype1isnotspecifictothesurfaceproteinsofthevirus.B. Antibodytype2preventsinteractionbetweentheRBCsandthevirus.C. InWellB,theRBCsandthesurfaceproteinsofthevirusdonotinteractwitheachother.D. InWellC,theantigen–antibodyinteractioninterfereswiththeRBCsbindingtothevirus.
9 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Use the following information to answer Questions 18 and 19.Considerthefollowingphotographofonioncellsundergoingcelldivision.Thesecellswerefoundinagrowingroottip.
R
S
N
M
Source:PIYAPONGTHONGDUMHYU/ Shutterstock.com
Question 18Whichoneofthefollowingisacorrectstatement?A. HomologouschromosomesarepairedinthecelllabelledR.B. EachchromosomeinthecelllabelledMwillcontainonemoleculeofDNA.C. SeparatedsisterchromatidsaremovingtooppositepolesofthecelllabelledS.D. ThenucleusofthecelllabelledNhashalfthenumberofchromosomescomparedtoitsparentnucleus.
Question 19 Thestageofcelldivisionatwhichthenuclearenvelopearisesfromfragmentsoftheparentnuclearenvelope,andthenucleolireappear,isshownbythecelllabelledA. M.B. N.C. R.D. S.
Question 20 Considercellsdividingbymeiosis.ThecellsproducedA. aretheresultofonenucleardivisionandtwodivisionsofthecytoplasm.B. havethesamenumberofchromosomesastheparentcell.C. aregeneticallyidenticaltoeachother.D. arehaploid.
2017BIOLOGYEXAM(NHT) 10
SECTION A – continued
Question 21 Duringmeiosis,theprocessofcrossingoverA. involvestheexchangeofgeneticmaterialbetweennon-sisterchromatidsofhomologouschromosomes.B. occursbetweensectionsofnon-homologouschromosomes.C. resultsinlessgeneticvariationinthegametes.D. occursduringthesecondmeioticdivision.
Question 22SynthesisofDNAmoleculesisrequiredintheproductionofnewcells.WhichoneofthefollowingisacorrectstatementaboutthesynthesisofDNAmolecules?A. DNAprimersactasastartingpointforthesynthesisofnewDNAmolecules.B. ThesynthesisofDNAmoleculesoccursintheG2stageofthecellcycle.C. OnlyonestrandoftheoriginalDNAmoleculeactsasatemplate.D. DNApolymerasejoinsnucleotidestoagrowingstrandofDNA.
Use the following information to answer Questions 23 and 24.Ricinisanaturallyoccurring,powerfulpoisonthataffectseukaryoticorganisms.Largemammalsthatingestsmallamountsofricincandiewithinthreetofivedays.Studieshaveconcludedthatricinstopsthemovementofaribosomealongaspecificmolecule.ThisspecificmoleculehasbeenlabelledMoleculeXinthediagrambelow.
ribosome Molecule X
direction of ribosome movement
Question 23WhatisthenameofMoleculeX?A. rRNAB. tRNAC. mRNAD. pre-mRNA
Question 24EukaryoticorganismsdiefromricinpoisoningbecausethericinimmediatelycausesA. nervedamagetomotorneurons.B. theprocessofmitosisinthecellstostop.C. irreversibledamagetoDNAinthenucleiofcells.D. theprocessofproteinsynthesisinthecellstostop.
11 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Question 25 AsectionofaDNAstrandhasthebasesequenceAGCGCATAGCAA.DuringDNAreplicationtoformthecomplementaryDNAstrand,amutationinvolvingasinglebasesubstitutionoccurredinthelasttripletofthissection.ThismutationwasthenpassedontothemRNAwhentranscriptionofthecomplementarystrandoccurred.ThebasesequenceofthemRNAcontainingthemutationcouldbeA. AGCGCAUAGCAAB. AGCGCAUAGUAAC. UCGCGUAUCGUUD. UCGCGUAUCAUU
Question 26 Considerthediagramofthechromosomesbelow.
X
Source:IaremenkoSergii/Shutterstock.com
ThestructureslabelledXareA. centromeres.B. spindlefibres.C. sisterchromatids.D. homologouschromosomes.
2017BIOLOGYEXAM(NHT) 12
SECTION A – continued
Use the following information to answer Questions 27 and 28.Tryptophanisanaminoacidthatisproducedbymanybacteria.GenesthatcodefortheproductionoftryptophanarefoundonbacterialDNAandtogetherarecalledthe trpoperon.Intheprocessofgeneregulation,arepressorprotein(trprepressor)bindstothetrpoperon.Whensuchbindingoccurs,theprocessoftryptophanproductionstops.Thisisillustratedinthediagrambelow.
trp repressorbinds to trp operon
trp repressor
production oftryptophan unable to
proceed
trp operon
DNA strand
Question 27 Whenthetrprepressorbindstothetrpoperon,whichoneofthefollowingenzymeswouldbeblockedfromfunctioningnormally?A. RNApolymeraseB. DNApolymeraseC. endonucleaseD. DNAligase
Question 28Whichoneofthefollowingfactorswouldincreasetheconcentrationofthetrprepressorinbacterialcells?A. lowconcentrationoftryptophanB. highconcentrationoftryptophanC. highconcentrationofDNAligaseD. lowconcentrationofDNApolymerase
13 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Use the following information to answer Questions 29 and 30.HaemophiliaAisarecessivegeneticdisorder.Humanswiththisdisordertendtobleedmorethannormalbecauseoneoftheproteinsneededinbloodclottingismissing.ThegenecontrollingtheproductionofthisproteinisfoundontheXchromosome.Thisgenehastwoalleles.
Question 29AfemalecarrierofhaemophiliaAA. willbehomozygouswithrespecttothisgene.B. hasonecopyofeachoftheallelesofthisgene.C. willhavethesamegenotypeasafemalewithhaemophiliaA.D. passesthealleleforhaemophiliaAtoallofherdaughters.
Question 30 ConsiderthechildrenofafatherwhosebloodclotsnormallyandamotherwhoisacarrierofhaemophiliaA.Whichoneofthefollowingisacorrectstatementaboutthechildrenoftheseparents?A. EachchildwillhaveanequalchanceofinheritinghaemophiliaA.B. Daughterswillhavea50%chanceofinheritinghaemophiliaA.C. Alldaughterswillbehomozygouswithrespecttothisgene.D. Sonswillhavea50%chanceofinheritinghaemophiliaA.
Question 31Inapopulation,atraitwillbemorelikelytoshowcontinuousvariationifA. thetraitisinfluencedbymanygenes.B. genescontrollingthetraitarecloselylinked.C. thereisalowmutationrateinthegenecontrollingthetrait.D. theenvironmenthaslittleeffectontheexpressionofthetrait.
2017BIOLOGYEXAM(NHT) 14
SECTION A – continued
Use the following information to answer Questions 32 and 33.Thepresenceofhornsandthecolourofhairingoats(Capra hircus)aregeneticallyinherited.Inaparticularbreedofgoats,haircolourmaybebrownorwhite.Thesegoatsmayhavehornsorhornsmaybeabsent.
Question 32 Crossesbetweenindividualgoatswereperformedandthephenotypesoftheoffspringwererecorded.Theresultsofthecrossesareshowninthetablebelow.
Cross Phenotypes of parents Phenotype(s) of offspring
1 brown×white brown
2 brown×brown somebrownandsomewhite
3 white×white white
4 horns×nohorns nohorns
5 horns×horns horns
6 nohorns×nohorns somewithhornsandsomewithnohorns
Basedontheinformationprovided,whichoneofthefollowingconclusionscanbemade?A. Allgoatswithbrownhairhavethesamegenotypewithrespecttohaircolour.B. Thebrown-hairedparentincross1isheterozygouswithrespecttohaircolour.C. Allgoatswithhornshavethesamegenotypewithrespecttothepresenceorabsenceofhorns.D. Thetwoparentswithouthornsincross6havedifferentgenotypeswithrespecttothepresenceor
absenceofhorns.
Question 33 Todetermineifthegeneforhaircolourandthegeneforthepresenceorabsenceofhornsarelinked,thefollowingcrosseswerecarriedout.
Cross Phenotypes of parents Phenotypes of offspring and ratio
1 brownhair,nohorns× whitehair,horns
allhavebrownhair,nohorns
2 brownhair,nohorns× brownhair,nohorns
9brownhair,nohorns:3brownhair,horns:3whitehair,nohorns:1whitehair,horns
3 brownhair,nohorns× whitehair,horns
1brownhair,nohorns:1brownhair,horns:1whitehair,nohorns:1whitehair,horns
4 brownhair,nohorns× whitehair,horns
4brownhair,nohorns:1brownhair,horns:1whitehair,nohorns:4whitehair,horns
EvidencethatthegenesarelinkedwouldbeprovidedbyA. cross1.B. cross2.C. cross3.D. cross4.
15 2017BIOLOGYEXAM(NHT)
SECTION A – continuedTURN OVER
Question 34Radio-isotopicdating(radiometricdating)isusedtodeterminetheageoffossilsandtheirsurroundingrocks.Whichstatementaboutradio-isotopicdatingistrue?A. Radio-isotopicdatingtechniquesareonlyreliablewhendatingfossilsthatwereformedlessthan
20millionyearsago.B. Radio-isotopicdatingcalculationsassumethatthebreakdownofaradioactiveisotopeoccursata
constantrate.C. Carbonisthebestelementtoprovideusefulradio-isotopicdatingevidenceforcalculatingtheageofall
fossils.D. Radio-isotopicdatingtechniquescannotprovideanestimateofhowmanyyearsagoafossilwas
formed;theyareonlyusefultocompareifonefossilisolderthananother.
Question 35Researchersstudiedthephylogeneticrelationshipbetweentwoamphibianspecies,SpeciesGandSpeciesH.Basedonmolecularhomology,whichoneofthefollowingwouldbeusefulevidencetohelpdeterminetherelationshipbetweenthetwospecies?A. Therateofaparticularmetabolicreaction,catalysedbythesameenzyme,isconsiderablyfasterin
SpeciesGthaninSpeciesH.B. Thestructureoftheeyemusclesissignificantlydifferentbetweenthetwospecies.C. Theaminoacidsequenceofaparticularproteinisthesameinbothspecies.D. ThemoleculetRNAispresentinbothspecies.
Question 36 ComparativegenomicsA. isatoolusedbyscientiststostudyevolutionarychange.B. comparesthebiogeographicaldistributionofpresent-dayspecies.C. isthestudyofthehomologousandanalogousstructuresofdifferentspecies.D. reliesontheabilityofscientiststoseparatedifferentcarbohydratesfromthecellsofdifferentspecies.
Question 37 Severalspeciesofflightlessbirdscanbefoundondifferentlandmassesoftheworld.ExamplesincludetheAfricanostrich,theAustralianemuandtheNewZealandkiwi.Recentstudieshavemadescientistsrethinktheevolutionaryrelationshipbetweenflightlessbirds.Scientistsnowhypothesisethattheseflightlessbirdshaveevolvedbyconvergentevolution.ThissuggeststhatA. thelossoftheabilitytoflydevelopedindependentlyineachofthethreebirdspecies.B. eachofthethreebirdspeciesoccupiesverydifferentecologicalniches.C. theostrich,theemuandthekiwisharearecentcommonancestor.D. therateofmutationineachofthethreebirdspeciesishigh.
2017BIOLOGYEXAM(NHT) 16
SECTION A – continued
Question 38 Whichofthefollowingcharacteristicsaresharedbybothhominoidsandhominins?A. colourvision,omnivorous,nails,opposablethumbs,simpletooluse,livingingroupsB. colourvision,carnivorous,highlydevelopedsenseofsmell,forward-facingeyes,solitarylivingC. poorvision,eatsonlyfruit,poorsenseofsmell,claws,highlydevelopedhearing,livingingroupsD. well-developedperipheralvision,herbivorous,poorsenseofsmell,forward-facingeyes,
well-developedhearing,livingingroups
Question 39 Thediagrambelowshowsthreeviewsoftheskeletonofahomininspecies.
Source:3drenderings/Shutterstock.com
Basedonyourknowledgeandtheinformationprovidedinthediagram,whichoneofthefollowingisacorrectstatement?A. ThespeciesshowninthediagramisolderthanAustralopithecus afarensis.B. Thespeciesshowninthediagramhasapelvicstructureallowingbipedallocomotion.C. Thespeciesshowninthediagramhasaslopingforeheadsimilartomodern-dayhumans.D. Thespeciesshowninthediagramhasprominentbrowridgessimilartothoseseeninallhominin
species.
17 2017BIOLOGYEXAM(NHT)
END OF SECTION ATURN OVER
Question 40 FossilbonesofthehomininspeciesHomo floresiensis werediscoveredinacaveontheIndonesianislandofFlores.Thefossilboneshavebeendatedfromabout100000to60000yearsago.Thissuggeststhatthisspecieslivedatthesametimeasmembersofourownspecies,Homo sapiens.ScientistslookedforevidenceofculturalevolutioninthecavewherethefossilremainsofH. floresiensis werefound.EvidenceofculturalevolutioncouldincludeA. footprintsindicatingthatH. floresiensiswasbipedal.B. handbonesthatindicatethatH. floresiensishadanopposablethumb.C. anaveragebodysizeinH. floresiensisthatissmallerthanthatofH. sapiens.D. H. floresiensis beingfoundwithvariousfossilisedburntanimalboneswithcutmarksonthem.
2017BIOLOGYEXAM(NHT) 18
SECTION B – Question 1–continued
Question 1 (6marks) Haemoglobinisthemoleculeinredbloodcellsthatdeliversoxygentocellsthroughoutthebody.Inadults,haemoglobinnormallyconsistsoffoursub-units:twosub-unitsofbeta-globinandtwosub-unitsofalpha-globin.Eachsub-unitisboundtoaniron-containingmoleculecalledhaem.Thehaemmoleculebindstooxygen.
a. Namethegroupofbiomacromoleculesthathaemoglobinbelongsto. 1mark
b. Sickle-celldisease(SCD)isagroupofblooddisorders.PeoplewithSCDmayhavejust asinglenucleotidechangeintheHBBgene–thesegmentofDNAthatcodesforthe beta-globinofthehaemoglobin.Thisresultsinanalteredhaemoglobinmolecule.
ExplainhowasinglenucleotidechangeintheHBBgenecanalterthestructureofthehaemoglobinmoleculeinpeoplewithSCD. 2marks
SECTION B – Short-answer questions
Instructions for Section BAnswerallquestionsinthespacesprovided.Writeusingblueorblackpen.
19 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
c. RecentadvancesinDNA-editingtechniqueshavegreatpotentialtocureconditionssuchasSCD.OnesuchtechniqueinvolvestheuseofRNA.RNAisamoleculecloselyrelatedtoDNA.
CompletethetablebelowtoprovideacomparisonbetweenDNAandRNA. 3marks
DNA RNA
Names of nucleotide bases present
Function 1
Function 2
2017BIOLOGYEXAM(NHT) 20
SECTION B – continued
Question 2 (4marks)Atransmissionelectronmicrographofpartofacellisshownbelow.Thenucleusofthecellhasbeenlabelled.
X
nucleus
Source:JoseLuisCalvo/Shutterstock.com
Thecellshownaboveisasecretorycell.Thesecretoryproductofthecellissynthesisedbyanorganelle,partofwhichisenclosedbythecirclelabelledX.
a. Namethisorganelle. 1mark
b. Describethetransportationpathwaytakenbythesecretoryproductfromtheorganellenamedinpart a.untilitleavesthecell. 3marks
21 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
Question 3 (5marks)a. i. Giveanexampleofacatabolicreactionthatoccursinacell. 1mark
ii. Justifywhythisreactionisclassifiedasacatabolicreaction. 1mark
b. AproteincalledAMP-activatedproteinkinase(AMPK)hasbeenshowntocontrolmetabolicreactionsincells.AMPKregulatesthelevelofATPinthecell,controllingtherateofbothanabolicandcatabolicreactionssothatthelevelofATPremainsoptimalforcellularactivities.
i. Completethefollowingtableusingthewords‘increases’or‘decreases’toindicatehow therateofcellularreactionsiscontrolledbyAMPKwhenthelevelofATPwithinthe cellfalls. 1mark
Type of cellular reaction
Catabolic Anabolic
Rate of cellular reaction
ii. Giveareasonforeachofyouranswerstopart b.i. 2marks
2017BIOLOGYEXAM(NHT) 22
SECTION B – Question 4–continued
Question 4 (7marks)Thesmokeproducedduringafireisusuallymoredangerousthantheheat.Twoofthemanytoxicchemicalsinthesmokeofafirearecarbonmonoxideandhydrogencyanide.Carbonmonoxidemoleculesbindtohaemoglobinmoleculesintheblood,reducingtheblood’scapacitytotransportoxygen.Thiscausesasignificantreductioninoxygensupplytothecellsofthebody.
a. Oxygenisrequiredfortheprocessofcellularrespiration.Thethreestagesofthisprocessarelistedinthetablebelow.
Completethetablebynamingthemissinginputsandoutputsofeachstageofcellular respirationwhennormaloxygenlevelsareavailable. 3marks
Stage Inputs Outputs
glycolysis
ADP+PiNAD++H+
ATPNADH
Krebscycle
ADP+PiNAD++H+
FAD+2H+
ATPNADHFADH2
electrontransportchain
ADP+PiNADHFADH2
ATPNAD++H+
FAD+2H+
b. Suggestwhybloodlactate(lacticacid)levelsmightbeusedtodiagnosecarbonmonoxidepoisoning. 1mark
23 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
c. Hydrogencyanideisaninhibitoroftheenzymecytochromecoxidase,animportantenzymeintheelectrontransportchain.
Explainhowamoleculesuchashydrogencyanidemayactasaninhibitoroftheenzymecytochromecoxidase. 2marks
d. Refertothegeneralbiochemicalpathwayshownbelow.
Enzyme AA
Enzyme BB
Enzyme CC
Enzyme DD E
DescribewhathappenswhenanyoneoftheenzymesA,B,CorDinthepathwayisinhibited. 1mark
2017BIOLOGYEXAM(NHT) 24
SECTION B – Question 5–continued
Question 5 (7marks) a. Onthediagramofthechloroplastbelow,uselabelledarrowstoindicatethepositionsofthe
followingstructures:• grana• stroma 2marks
Region B Region A
Source:BlueRingMedia/Shutterstock.com
25 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
b. Twostudentssetupanexperimenttomeasurethereactionrateofthelight-dependentstageofphotosynthesis.Thylakoidmembraneswereremovedfromchloroplastsandsuspendedinsolution.Themembraneswerethenexposedtodifferinglightintensitiesandtherateofthereactionwasmeasured.StudentAwasgiventhylakoidmembranesfromRegionAand StudentBwasgiventhylakoidmembranesfromRegionB.Bothfollowedthesamemethod.
Theresultsobtainedbybothstudentsareshownbelow.
Student A Student B
reactionrate
light intensity
reactionrate
light intensity
i. Whatcouldthestudentshavemeasuredintheirexperimenttoindicatethereactionrate? 1mark
ii. Statetwofactorsthateachstudentmustcontrolwhensettinguptheirexperimentsothattheycancomparetheirresultsandknowthattheirresultsarevalid. 2marks
iii. Eachstudentsetuptheirexperimentinanidenticalmanner.
Explainthedifferencesobservedintheirresults. 2marks
2017BIOLOGYEXAM(NHT) 26
SECTION B – Question 6–continued
Question 6 (8marks)a. Innateimmunityhelpsprotecthumansfrominvadingpathogens.
Howdoestheskinhelpprotecthumansfrominvadingpathogens? 1mark
Researchsuggeststhatthemicroorganismsthatnormallyliveontheskinhaveaverycomplexandbeneficialrelationshipwiththeirhosts. Staphylococcus epidermidis is oneofthemostcommonspeciesofbacteriaonhumanskin.Toinvestigatethepossiblebeneficialroleofthisbacterium,scientistsdesignedanexperimentasfollows.Twogroupsofmicewereused.ThemiceinGroup1hadS. epidermidisappliedtotheirskin.ThemiceinbothGroup1andGroup2wereinfectedwithapathogenicfungus.Themicewereleftforseveraldays,andthenscientistsmeasuredthelevelsofantigen-presentingcells(APCs)andcytotoxicTcells(Tccells)intheskinofthemicefrombothgroups.
b. DescribetheroleofAPCsinanimmuneresponse. 2marks
c. InwhichtypeofimmuneresponsewouldtheTccellsandAPCsplayapart? 1mark
27 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
d. InadditiontothelevelsofAPCsandTccells,thegrowthofthepathogenicfunguswasalsomeasuredinallofthemice.Theresultsofthisexperimentaresummarisedinthetablebelow.
Mice Level of APCs Level of Tc cells Growth of the pathogenic fungus
Group1 high high nogrowthonskin
Group2 low low funguscoveringalargeareaofskin
i. Stateahypothesisthatthisexperimentistesting. 1mark
ii. Explainwhichgroupofmiceservedasacontrolinthisexperiment. 1mark
iii. Explainthedifferenceingrowthofthepathogenicfungusinthetwogroupsofmice. 2marks
2017BIOLOGYEXAM(NHT) 28
SECTION B – Question 7–continued
Question 7 (8marks) Researchersstudyingtheprocessoffloweringinaplanthypothesisedthattheonsetoffloweringiscontrolledbytheregulationofaspecificgene.Theresearchersdecidedtosequencethegene.
a. Whatinformationisobtainedfromgenesequencing? 1mark
AportionoftheDNAoftheplantwasamplified.TheDNAamplificationmixturewasmadeupofthespecificgenesegment,asupplyoffournucleotidebases,Taq polymeraseandDNAprimers.Thetemperatureofthemixturewaschangedasfollows.
Step Temperature
1 94°C
2 55°C
3 72°C
b. DescribewhathappenstotheDNAwhenthemixtureisheatedduringStep1.Nametheendproductofthisstage. 2marks
c. WhatisthefunctionoftheDNAprimersinthemixture? 1mark
d. Explainwhythetemperaturewasreducedto55°CinStep2andthenincreasedto72°CinStep3. 3marks
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SECTION B – continuedTURN OVER
e. Theresearchersrepeatedthisamplificationprocessthreemoretimesinseparatemicrotubes.Theythencarriedoutgelelectrophoresisonsamplesfromeachofthefourmicrotubes.Theirresultsareshownbelow.
Microtube1
Microtube2
Microtube3
Microtube4
directionof travel
loadingwells
SuggestapossiblereasonwhytheresultsforMicrotube3aredifferentfromtheresultsfortheotherthreemicrotubes. 1mark
2017BIOLOGYEXAM(NHT) 30
SECTION B – Question 8–continued
Question 8 (7marks) Considerthefollowingpedigree.
1 2
1 2 3 4 5 6
3 4
I
II
III
2 31
IndividualII-4displaysatraitthatisinherited.TheinheritanceofthistraitisX-linkeddominant.ItisknownthatthistraitisalsofoundinindividualswithinthisfamilyingenerationsIandIII.
a. i. Inthepedigreeabove,shadeinallindividualswhomustalsodisplaythesametraitasindividualII-4. 1mark
ii. Giveareasonforshadinginthoseindividuals. 1mark
31 2017BIOLOGYEXAM(NHT)
SECTION B – continuedTURN OVER
b. A different inheritedtraitwasinvestigatedinafamily.Individualsdisplayingthistraithavebeenshadedinthepedigreebelow.
1 2
1
2 31
2 3 4 5 6
4
3 4
I
II
III
i. Determinethemodeofinheritanceofthistrait. 1mark
ii. Givetwopiecesofevidencetosupportyouranswertopart b.i. 2marks
iii. IfindividualsIII-3andIII-4haveachild,whatistheprobabilitythatthischildwillhavethetrait?Showyourworking. 2marks
2017BIOLOGYEXAM(NHT) 32
SECTION B – continued
Question 9 (5marks) InAfrica,themalaria-carryingmosquitoAnopheles gambiae hasbeenthefocusofa mosquito-eradicationcampaignusingtheinsecticidepyrethroid.Researchersfoundthatallele1ofgeneL1014producesresistancetopyrethroidinthesemosquitoes;however,allele2doesnotproduceresistancetopyrethroid.Researchersstudiedthefrequencyofbothoftheseallelesoveraperiodoftime.Intheparticularpopulationofmosquitoeswherethisstudywascarriedout,anintenseprogramofpyrethroidsprayingwasbegunin2008andwasmaintaineduntil2011.Theresultsoftheallelefrequencystudiesarepresentedinthetablebelow.
Allele frequencies for gene L1014 in A. gambiae
Allele type Frequency in 2007 Frequency in 2011
1 36.4% 77.7%
2 63.6% 22.3%
Itisconsideredthatthisdataprovidesevidencethattheprocessofnaturalselectionhasoccurred intheA. gambiae species.
a. Usingtheinformationabove,explainhownaturalselectionhasoperatedinthispopulationoftheA. gambiae mosquito. 3marks
b. Basedontheinformationabove,hasthegenepoolofthispopulationoftheA. gambiae mosquitobeenalteredbythesprayingofthisinsecticide?Explainyouranswer. 2marks
33 2017BIOLOGYEXAM(NHT)
SECTION B – Question 10–continuedTURN OVER
Question 10 (9marks)Sixdifferentbeetlespecieshavebeenstudiedbyscientists.ThesixspeciesarefoundwithincavesinthenorthernpartofSpain(seemap).AllsixspeciesbelongtothegenusGeotrechus.Therelativepositionsofthesixspecieswithintheregionareshowninthediagrambelow.
location of beetle species
S
ST
U
V
Species SSpecies USpecies W
SUW
W
Species TSpecies VSpecies X
TVX
X
Key
a. ScientistsusedDNAsequencesandproteinstructurestohelpclassifythesixbeetlespecies.
Describeotherevidencethescientistscouldusetohelpclassifythebeetlesintodifferentspecies. 2marks
b. Thescientistsgatheredinformationtoconstructaphylogenetictreeforthesixbeetlespecies.
Whatinformationisdisplayedinaphylogenetictree? 1mark
2017BIOLOGYEXAM(NHT) 34
SECTION B – Question 10–continued
Byexaminingfossilevidenceinthearea,thetimingoftheappearanceofeachofthespecieshasbeendetermined.Thisisshowninthetablebelow.
Location of beetle species Species present Time period in which species were found
(millions of years ago)
R
RR
RR
R
R
R SpeciesR 24
SS
S
R
R
R
R
R SpeciesRS SpeciesS
16
T
SS
S
R
R
R
R SpeciesRS SpeciesST SpeciesT
8
U
V
TS
S
R
R
R SpeciesRS SpeciesST SpeciesTU SpeciesUV SpeciesV
6
W
X
U
TS
S
V
S SpeciesST SpeciesTU SpeciesUV SpeciesVW SpeciesWX SpeciesX
2
Source:adaptedfromAFaille,CBourdeau,XBellesandJFresneda,‘Allopatricspeciationillustrated: ThehypogeangenusGeotrechusJeannel,1919(Coleoptera:Carabidae:Trechini),
withdescriptionoffournewspeciesfromtheEasternPyrenees(Spain)’, inArthropod Systematics & Phylogeny,73(3)2015,p.453
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SECTION B – continuedTURN OVER
c. ScientistscomparedDNAsequencesinfourmitochondrialgenesandtwochromosomalgenesfoundinthenucleusofthebeetles.
IdentifythetwobeetlespeciesthatwouldhavetheleastnumberofdifferencesintheirDNAsequences.Explainyouranswer. 3marks
d. Scientistsexplainedtheappearanceofthesixbeetlespeciesbysuggestingthat,overtime,allopatricspeciationhadoccurred.
Describetheprocessofallopatricspeciation. 3marks
2017BIOLOGYEXAM(NHT) 36
Question 11 (4marks)Coralreefsarefoundinoceansaroundtheworld.Coralsareanimalsthatbuildupcalciumcarbonateskeletons.Single-celledalgaelivewithinthecoraltissues.QueenslandscientistshavereportedthatmanyofthecoralsinaregionoftheGreatBarrierReefhaverecentlybecomebleached.Bleachingoccurswhenthesingle-celledalgaeleavethecoraltissuesduetoenvironmentalchanges.Coralsturnwhitewithoutthealgaeandmaydie.Thisbleachinghasbeenattributedtoanincreaseinwatertemperatureandacidity.Twoapproacheshavebeenproposedtohelpreversethebleachingoccurringinthecoralreefs.
Approach 1Scientistsselectivelybreedcoralscontainingsingle-celledalgaewithinalaboratorysetting.Particularcoralswithalgaearethenreintroducedintothecoralreef.
a. Explainhowselectivebreedingmayhelpreversethebleachingofthecoral. 2marks
Approach 2Single-celledalgaefromthecoralreefareexposedtomutagenswithinalaboratorysetting.Someofthesealgaearereintroducedbackintothecoralreefs.
b. i. Whatwouldbethepurposeofexposingthesingle-celledalgaetomutagens? 1mark
ii. Whatisadisadvantageofthisapproach? 1mark
END OF QUESTION AND ANSWER BOOK
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