武汉大学期末考试试题

武汉大学生命科学学院

2003-2004学年第一学期期末考试

《分子生物学》试卷及参考答案

FinalexamofMolecularBiologyCourse(Spring2004)

写在参考答案前面的话：

＞该课程考试目的是考查学生对所学知识掌握的情况，除选择题外，其他题目的答

案基本都不是唯一的。你可以从不同的角度去阐明一个概念。

＞公布参考答案的目的：为该课程画个句号，让学生过个安心暑假

＞Bestwishestoallofyou

PARTI:DESCRIPTION(2pointseach)

Youranswershoulddescribewhateachitemisandhowitfunctionsinthecell.Diagrams,

structureandsequenceinformationshouldbeincludedinyouranswer,asnecessary.

1.Yeastartificialchromosome:

①酵母人工染色体(0.5pobu)

②containscomponentsrequiredforreplicationandsegregationofthenaturalyeast

chromosome,includingtwotelomericsequences(TEL),onecentromere(CEN)

andoneautonomouslyreplicatingsequences(ARS)(0.75point)

③containsgenesactasselectivemarkersinyeastandproperrestrictionsites(0.75

point)

④canaccommodategenomicDNAfragmentsofmorethan1Mb(0.5point)

2.RNAinterference:

①RNA干扰(0.5point)

②aconservedbiologicalresponsetodouble-strandedRNA(1point)

(3)regulatestheexpressionofprotein-codinggenesthroughsiRNAormiRNA(1

point)

(4)thedsRNAisrestrictedbyDICER,thenRISCmediatesthesiRNAandmiRNA

relatedRNAdegradationandtranslationinhibition,respectively.(1point)

3.Proteomics

①蛋白组学(0,5point)Thestudyoftheproteomeusingtechniquesofhigh

resolutionproteinseparationandidentification(1.5point)

④Thebestseparationmethodistwodimensionalgelelectrophoresis,theindividual

proteinspotsarethencutfromthegelandtreatedwithproteasetoproduceasetof

peptidescharacteristicofthatprotein.Theprecisemassesofeachpeptideinthe

samplearethendeterminedbyMALDImassspectrometry.Theresultedpeptide

massfingerprintofthatproteinisthencomparedtoadatabasetodeducethe

functionofthatproteinetc.(1.5point)

4.Shine-Dalgarnosequence

①SD序列(0.5

②Aconservedsequence8-13ntupstreamofthefirstcodontobetranslated(1

point).

(3)ThissequencewasdiscoveredbyShineandDalgarno(0.5point)

(4)Thesequenceispurine-richandcontainsallorpartof5,-AGGAGGU-3,(0.5

point)

⑤Canbase-pairwiththe3'-endofthe16SrRNA(0.5point)

5.Alternativesplicing

①可变剪接(0.5point)

②ThegenerationofdifferentmaturemRNAsfromaparticulartypeofgene

transcriptbychoosingdifferent5'-and3'-splicesites(2point).

6.Ribozyme

①核酶(0.5point)

②anRNAmoleculecapableofcatalyzingachemicalreaction(2point).

7.p-dependenttermination

①p-依赖型转录终止(0.5pobu)

②Duringbacterialtranscription,someterminatorsitesdonotformstronghairpins,

thusterminationofthetranscriptionbybacterialRNApolymeraserequires

theassistanceofanaccessoryfactorcalledrho(p)protein(2point).

8.RNAediting

①RNA编辑(0.53m)

②AformofRNAprocessinginwhichnucleotidesequenceoftheprimary

transcriptisalteredbyeitherchanging,insertingordeletingresiduesatthe

specificpointsalongthemolecule(2point).

9.DNAlesions

①DNA损伤60.5point)

②AnalterationtothenormalchemicalorphysicalstructureoftheDNA(2point).

(3)ThelesionscanleadtocelldeathorDNAmutation(1point).

10.Proteintargeting

①蛋白定位(0.5point)

②Synthesisofeukaryoticproteinsisusuallyoccurredincytoplasm(0.5point).

(3)However,manyproteinsneedtobetransportedtospecificcellularlocations,such

asnucleus,mitochondrionorchloroplast,toexerttheirbiologicalfunctions.This

processiscalledproteintargeting(1point).

(4)Theultimatecellularlocationofproteinsisoftendeterminedbyspecific,relative

short,aminoacidsequenceswithintheproteinsthemselves.Thesequenceinside

ofaproteindeterminingthecellularlocationoftheproteiniscalledsignal

sequence(1point).

PARTII:MULTIPLECHOICES(1pointseach)

Selecttheonebestanswerforeachquestion.

1.Thecatalyticactivityforpeptidebondformation(thepeptidyltransferaseactivity)is

locatedinthe:

1)RNAofthelargeribosomals“bu几it.

2)leadersequenceofthemessengerRNA.

3)RNAofthesmallribosomalsubunit.

4)proteinsofthesmallribosomalsubunit.

5)proteinsofthelargeribosomalsubunit.

2.Bidirectionalandsemi-conservativearetwotermsthatreferto:

1)transcription.

2)translation.

3)reDlication.

4)alloftheabove.

5)noneoftheabove.

3.Thefactthatmostaminoacidsarespecifiedbymultiplecodonsisknownas:

1)the“wobble”phenomenon.

2)theuniversalityofthegeneticcode.

3)codonbias.

4)theanticodonhypothesis.

5)theredundancyofthegeneticcode.

4.RNApolymeraseIistheeukaryoticenzymeresponsiblefor:

1)ircmscrimionofribosomalRNA.

2)transcriptionoftransferRNAandothersmallRNAspecies.

3)transcriptionofmessengerRNA.

4)initiationofOkazakifragmentsynthesisinDNAreplication.

5.RestrictionenzymescancleaveDNAthatiseithersingle-strandedordouble-stranded,

aslongasitcontainstheappropriaterecognitionsite.

1)True2)False

6.Informationaboutthesequenceofthecodingregionofageneisbestobtainedfrom:

1)aYACclone.

2)agenomicclone.

3)acDNAclone.

4)theprotein.

7.Achromatographymethodthatcanbeusedspecificallytopurifyproteinsbasedontheir

chargeis:

1)gelfiltrationchromatography.

2)ion-exchcmgechromatography.

3)DNAaffinitychromatography.

4)antibodyaffinitychromatography.

8.AnonsensemutationisachangeintheDNAsequencethatresultsin:

1)asmalldeletionorinsertion.

2)anaminoacidchangeintheproteinencodedbythegene.

3)aprematurestopcodon.

4)alloftheabove.

5)noneoftheabove.

9.Aproteincomplexinvolvedindegradationofproteinswithinthecellisknownasthe:

1)ubiquiiin/Droteasomesystem.

2)molecularchaperone.

3)chaperonin.

4)ribosome.

5)Krebs/TCAcycle.

10.bindstotherepressorandturnonthetranscriptionofthestructuralgenesinthe

Lacoperon.

1)cAMP

2)lactose

3)allolactose

4)CRP

11.WhichofthefollowingRNAspeciesisinvolvedindegradationofthemRNA

containingcomplementarysequence

1)miRNA

2)siRNA

3)tRNA

4)5SRNA

5)U3snRNA

12.Thegenomesequencingprojectsareconfirmingthetheorythatgenomesizeisdirectly

proportionaltothenumberofgenescontainedwithinthatgenome.Inotherwords,a

genomethatis10timesasbigwillcontainsapproximately10timesasmanyprotein

codinggenes.

1)True2)Fake

13.HeLacells,derivedfromahumancervicalcarcinoma,areabletopropagate

indefinitelyincultureandarethereforeknownasa(n):

1)tissueculture.

2)tumor.

3)transgeniccellline.

4)immorializedcellline.

14.E.colicellsaresmallerthanyeastcells.

1)True2)False

15.WhichofthefollowingdomainsisnotaDNAbindingdomain

1)Proline-richdomains

2)Helix-turnhelixdomains

3)Zincfingerdomains

4)Basicdomains

16.Theaminoacyl-tRNAsynthetasesdistinguishbetweenabout40differentshapedtRNA

moleculesinthecells.

1)True2)False

PARTIII:SHORTQUESTIONS(8pointseach)

1.Howdobacterialreplicationstartandaccomplished.Remembertoincludethe

proteins/enzymesandimportantDNAsequenceinvolvedinthisprocess.

Initiation(3points):

①replicationofthebacterialchromosomeistightlycoupledtothegrowthcycle.

②TheE.colioriginiswithinthegeneticlocusoriCthatcontainsfour9bpbinding

sitesfortheinitiatorproteinDnaA.

(3)SynthesisofDnaAiscoupledtogrowthratesothatthereplicationofthebacterial

chromosomeiscoupledtothegrowthcycle.

(4)OncethecellularlevelofDnaAreachesacriticallevel,DnaAproteinformsa

complexof30-40moleculesattheoriCDNA,whichfacilitatesmeltingofthree

13bpAT-richrepeatsequencestoallowbindingofDnaBprotein.

⑤DnaBproteinisaDNAhelicasethatutilizestheenergyofATPhydrolysisto

meltdsDNA.

⑥ThessDNAcreatedbyDnaBiscoatedwithsingle-strandedbindingprotein(Ssb)

toprotectitfrombreakageandtopreventtheDNArenaturing.

⑦TheDNAprimasethenattachestotheDNAandsynthesizesashortRNA

primertoinitiatesynthesisoftheleadingstrandofthefirstreplicationfork.

Unwinding(1point)

①Forreplicationtoproceedawayfromtheorigin,DNAhelicasesmusttravel

alongthetemplatestrandstoopenthedoublehelixforcopying,whichis

accomplishedbythejointeffortsofDnaBandSsb.

②UnwindingcausespositivesupercoilingoftheunwoundDNA;thepositive

supercoilingisrelaxedcontinuouslybytheintroductionoffurthernegative

supercoilsbytypeIItopoisomerasecalledDNAgyrase.

Elongation(3points)

①Initiationofthereplicationofthelaggingstrand.Asthenewlyformedreplication

forkdisplacestheparentallaggingstrand,amobilecomplexcalledaprimosome,

whichincludestheDnaBhelicaseandDNAprimase,synthesizesRNAprimers

every1000-2000ntonthelaggingstrand.

②BothleadingandlaggingstrandprimersareelongatedbyDNApolymerase

IIIholoenzyme.Thismultisubunitcomplexisadimmer,onehalfsynthesizing

theleadingstrandandtheotherthelaggingstrand.

(3)Laggingstrandsynthesis.DNApolymeraseIIIholoenzyme:asubunit-theactual

polymerase,£-a5'proofreadingexonuclease.DNApolymeraseIremovesthe

laggingstrandprimersandfillsintheresultedgaps.DNAligasemakesthefinal

phosphodiesterbondbetweenfragments.

Terminationandsegregation(1points)

©Tworeplicationforksmeetattheterminatorsites(terminus)

②tusgeneproductbindstotheterminusandactsasaninhibitorofDnaB

helicase.

③Whenreplicationiscompleted,thetwointerlinkeddaughtercirclesare

unlinkedbytopoisomeraseIV.

2.Designexperimentstocloneayeastgeneandexpressthisgeneinyeast.

Clone(4points):

①PCRamplificationofthegeneofinterest,includingtwoproperrestrictionsitesat

theendsofthePCRamplifiedDNA

②Chooseacloningvector:itcouldbearegularcloningvectorthatiscapableof

propagatinginE.coli,easytoextractfromE.coliandmanipulatedintesttubes.

Itcouldalsobeashuttleandexpressionvectorthatalsocontainstheyeast2|i

origintoallowtheplasmidreplicationinyeast,theselectivemarkertoallowthe

plasmidcontainingcellsgrow,thepromotertoallowthegeneofinteresttobe

transcribed,apoly(A)siteforadditionofpoly(A)tailonthetranscript.

Nomatterwhattypeofthevectorischosen,plasmidshallbepreparedfromtheE.

colicells.

(3)Restrictiondigestionofbothplasmidandthegeneofinterestwiththesame

restrictionsites.

④Ligationandtransformation

⑤Selectionandidentificationofthetransformantstoobtaintheclonecontainingthe

rightrecombinantplasmid.

Expression(4points):

(6)Ifashuttleandexpressionvectorischosenasdescribedinstep②,theexpression

processwillincludepreparationoftherecombinantDNAfromE.colicells,

2transformationofyeastcellswiththerecombinantDNA,3selectionofthe

transformants,4growthofthetransformants,dexpressionofthegenebyinduction

ofthetranscriptionfromthepromoterand6detectionoftheexpressedRNAand/or

protein.Inductionisnotrequiredifaconstitutivepromoterisused.(4points)

©Ifaregularcloningvectorischosenasdescribedinstep②,asubcloneneedtobe

obtainedtoallowthegeneofinterestbeingclonedintoashuttleandexpression

vectorsameasdescribedinstep②.ThenexpressionisperfoiTnedthesameas

describedin⑥.

3.Belowisthemultiplecloningsite(MCS)oftheplasmidvectorpUC18andthe

N-terminalandC-terminalsequenceofproteinX.NotethattheMCSconstitutesapart

oftheLacZopenreadingframe.SupposethatyouaregoingtoclonetheproteinX

geneintopUC18,sothatyourtargetgeneistranscribedunderthecontrolofLacZ

promoter,andtranslatedwiththeLacZgenetoproduceafusionprotein.Youare

requestedtouseBamHlandPstItothecloneXgene,pleaseaddtheserestriction

sitesonthecorrespondingpositionoftheXgene.Remembertomaintainthe

readingframeoftheXgenewiththeLacZgene

(l)MCSofpUC18

EcoRiSadKpniStnalBamHIXbalSallPsfl

ACGAATTCGAGCTCGGTACCCGGGGATCCTCTAGAGTCGACCTGCAGGCATGCA

ThrAsnSerSerSerVaiProUlyAsprroLeuuiuSerThrCysArgHisAla

LacZ

(2)N-terminalsequenceofXgene,ATGACCccuCAUAACGGCGAC...

MetThrProHisAsnGlyAsp...

(3)C-terminalsequenceofXgene....GAUAGUACAGCUGCCAAGTAA

...AspSerThrAlaAlaLys

ANSWER：GGATCCNATGACCCCUCAUAACGGCGAC(N-terminus)

GAUAGUACAGCUGCCAAGTAACTGCAG(C-terminus)

PARTIV:MAJORQUESTIONS(20pointseach)

1:PleasedescribehowanmRNAgeneistranscribed,processedandtranslatedinhuman

cells.Whatarethepossiblemechanismsinregulatingtheexpressionofthisgene?

①Transcription:focusingontranscriptioninitiationdescribedonp222ofthe

textbook.(5points)

②Processing:5'capping(additionofam7Gtothe5'endoftheRNApolII

transcriptcatalyzedbymRNAguanyltransferase/cappingenzyme)(1.5point),

intronsplicing(removalofintronbysplicesomethatcontains5snRNAsand

manyproteins.Firststep-cleavageat5'splicesiteandtheconservedAbeing

linkedtothe59-endoftheintron,secondstep-3'cleavageandexonligation)

(2points),39cleavageandpolyadenylation(First-assemblyofthe

recognitioncomplexonthepolyadenylationsite,second-poly(A)

polymerase/PAPcleavesthetranscriptatthissite,third-PAPaddsupto250

Aresiduestothe3'endofthetranscript)(1.5point).

(3)Translation'.Initiation,elongationandtermination(p276,278)(5points)

④Regulation'.Firstly,regulationcanoccuratthetranscriptionlevel,for

example,throughinteractionofthetranscriptionfactorswiththepromoteror

UREtoactivateorrepressthetranscription(2.5point).Secondly,regulation

canoccuratthepost-transcriptionlevel,forexample,alternativetranscription

oralternativepoly(A)site(2.5points).

2(20points):Abacteriumisfoundtometabolizeararesugarproducedbyaplantthatthe

bacteriagrowon.However,thebacteriapreferglucoseastheenergysource.Theproblem

is,ifyouwanttofinishthiscoursewithasatisfiedscore,youmustfigureoutthe

regulatorymechanismthatthebacteriausedtodeterminethesugarchoice.

Thegeneinvolvingintheraresugarmetabolismhasbeenidentifiedasfun3.Youcan

usenorthernblottoanalyzetheexpressionoffun3anduseDNAfootprintingtoanalyze

thebindingofproteinstothecontrolelementsoffun3gene.Thefollowingtableshowsthe

experimentalresults

GlucoseRaresugarLevelsofBindingofproteins

presencepresencefun3RNA

---ProteinAbindstothepromoterregion

ProteinCbindsupstreamofthepromoter

+--ProteinAbindstothepromoterregion

-++++ProteinBbindstothepromoterregion

ProteinCbindsupstreamofthepromoter

+++ProteinBbindstothepromoterregion

Questions:

1.Pleaseproposeamechanismtoexplaintheaboveresults.Youshouldfocusonthe

question“Howdoestheexpressionoffun3geneistightlyregulatedsothatitisonly

highlyexpressedwhentheraresugaristheonlycarbonsource".Youmustanswer

whatproteinsA,BandCare.(8points)

ProteinA-repressor,proteinB-RNApolymerase,proteinC-CRP/CAP

Regulatorymechanism:

①Intheabsenceofraresugar,therepressorproteinbindstothepromoter

regionpreventingthebindingofRNApolymerase,transcriptionofthe

fun3geneisnotpossible.Therefore,nofun3RNAisobserved.

②Inthepresenceofraresugar,repressorproteincannotbindtothepromter,

allowingtheRNApolymerasetobindandinitiatetranscription.However,

thepromoterofthefun3genemaybeaweakpromoter,transcriptionis

notefficientintheabsenceofactivator.Theactivatorofthe力优3gene

transcriptionisregulatedbyglucoselevel.Theabsenceofglucose

activatestheactivatorproteinandallowstheproteinbindingupstreamof

thepromotertoactivatethetranscriptionoffun3.

2.HowisproteinAregulated?(2points)

(1)glucoseturnstherepressoron

(2)glucoseturnstherepressoroff

(3)theraresugarturnstherepressoron

(4)theraresugarturnsthe"Dressoroff

3.HowisproteinCregulated?(2points)

(1)glucoseturnstheactivatoron

(2)glucoseturnstheactivatoroff

(3)theraresugarturnstheactivatoron

(4)theraresugarturnstheactivatoroff

4.Howcouldyoumakethebacteriaalwaysusetheraresugarastheenergysourceeven

inthepresenceofglucose?(8points)

Thesimplestway:Changethepromoteroffun3genetoastrongpromotercontaining

alltheconsensussequence.Thus,fun3geneisalwayshighlyexpressedwhenrare

sugarexists.

(其他的答案也可以酌情给分)

武汉大学生命科学学院

2004-2005学年第二学期期末考试

《分子生物学》试卷

FinalexamofMolecularBiologyCourse(Spring2005)

年级专业学号姓名成绩

PARTI:DESCRIPTION(2.5pointseach)

Youranswershoulddescribewhateachitemisandhowitfunctionsinthecell.Diagrams,

structureandsequenceinformationcouldbeincludedinyouranswer,asnecessary.

1.Affinitychromotography

2.microRNA

3.Alternativesplicing

4.Insulator

5.Riboswitch

6.Wobbleconcept

7.Topoisomerase

8.Replisome

9.tRNAcharging

10.tmRNA

PARTII:SINGLECHOICES(2pointseach)

1.Weakchemicalinteractionsareessentialinthebiologicalsystem.Whichofthe

followingstatementaboutweakchemicalinteractionisNOTTRUE?

1)VanderWaalsforcesandhydrogenbondsareallweakchemicalinteractions.

2)Weakbondsareconstantlymadeandbrokenatphysiologicaltemperature.

3)Hydrophobicinteractionsstabilizemacromolecules.

4)Covalentbondsaretheimportantforcesforprotein-proteininteraction.

2.WhichofthefollowingstatementsonDNAstructureisTRUE?

1)DNAcanonlyformbothright-handedhelices.

2)ThemajorgrooveofDNAhelixcontainsmorechemicalinformationthanthe

minorgroovedoes.

3)AllDNAbindingproteinsrecognizethemajorgrooves.

4)LinkingnumberischangeablepropertyforacccDNA.

3.RNAcanfolduptocomplextertiarystructurebecause

1)RNAchainisusuallysingle-strandedandformlong-rangeinteractionsin

additiontolocaldoublehelicalstructure.

2)RNAcontainsriboseanduracil.

3)SomeRNAsareenzymes.

4)RNAcanformpseudoknotstructure.

4.WhichofthefollowingfactorsdoesNOTcontributetothedecreasedgenedensityin

eukaryotes?

1)Increaseingenesize

2)Increaseinintergenicsequences

3)Increaseintheintronsequences

4)Increaseingenome-widerepeatsequence

5)Increaseinthetelomeresequenceandcomplexity

5.Thechromosomeelementimportantforchromosomesegregationis

1)Telomere

2)Centromere

3)Originofreplication

4)Replicationfork

6.WhichofthefollowingpersonswontheNobelprizebecauseofhis/hercontributionin

discoveryoftransposableelement?

1)Bai'baraMcClintock

2)JoanSteitz

3)FrancisCrick

4)PhilipSharp

7.WhichofthefollowingmechanismsisnotrelatedtoDNAdamagerepair?

1)Baseexcisionrepair

2)Nucleotideexcisionrepair

3)Translesionrepair

4)Mismatchrepair

5)Double-standbreakrepairpathway

9.WhichofthefollowingstatementsfortranslationisNOTCORRECT?

1)Ribosomecontainsboththedecodingcenterandpeptidyltransferasecenter

2)ThepeptidyltransferaseactivityisresidedinthelargeribosomalRNA

3)RibosomecandirectlyinterpretthegeneticinformationonthemRNAintothe

correspondingaminoacidssequence

4)PeptidebondformationandEF-GdrivetranslocationofthetRNAandthemRNA

10.WhichofthefollowingstatementsonhomologousreplicationisNOTCORRECT?

1)Hollidaymodelillustrateskeystepsinhomologousrecombination

2)Homologousrecombinationisofteninitiatedbydouble-strandedbreaksinDNA.

ItisknownthatSpol1generatesdouble-strandedbreaksineukaryote.

3)RecBCDhelicase/nucleaseprocessesbrokenDNAmoleculesandgeneratesa

single-strandedend.

4)RuvABcomplexandDmclspecificallypromotesbranchmigrationinbacteria

andeukaryotes,respectively.

PARTIII:SHORTQUESTIONS(CHOOSEFIVEQUESTIONSTOANSWER)

(6pointseach)

1.Whatisthecentraldogma?

2.Comparethechemistryandmechanismofsplicingofthecommonpre-mRNAintrons

andgroupIandgroupIIintrons.

3.Brieflydescribeorillustratehowanextracellularsignalcanalterintracellulargene

expression.

4.WhatarethemolecularmechanismsthatkeeptheDNAreplicationerrorrateaslowas

10-9incells?

5.Comparethemechanismandconsequenceofsite-specificrecombinationand

transposition.

6.Usetwoexamplestoillustratethatbacterialgeneregulationcanoccuratandafterthe

transcriptioninitiation.

7.Describethemoleculareventsoccurredatareplicationfork?Whythereplicationfork

canmovetoonedirectionalthoughtheleadingstrandandlaggingstrandare

antiparallelandbothsynthesizedinthe5'-3'direction?

PARTIV:MAJORQUESTIONS(12.5pointseach)

1:Comparetheinitiation,elongationandterminationofthetranscriptionofa

protein-encodinggeneinprokaryoteandeukaryote.

2:Afteryoulearnedthemolecularbiologyclass,youareveryinterestedinstudying

functionoftheeukaryoticTra-2protein.Obviously,thefirstchallengeistoobtainalarge

amountofpureTra-2protein.Pleasedescribetheproceduresthatyouwouldliketousein

ordertogetthedesiredTra-2protein.

武汉大学生命科学学院

2007-2008学年第一学期期末考试

《分子生物学》A试卷

FinalexamofMolecularBiologyCourse(Fall2007)

年级(Grade)专业(Major)

姓名Name学号(StudentID)

PARTI:DESCRIPTION(2pointseach)

Youranswershoulddescribewhateachitemisandhowitfunctionsinthecell.Diagrams,

structureandsequenceinformationcouldbeincludedinyouranswer,asnecessary.

1.Trombonemodel

2.TFIID

3.Telomerase

4.RNAediting

5.Tandemmassspectrometry

6.tRNAsynthetase

7.Viral-likeretrotransposons

8.Transcriptionalsilencing

9.Suppressionmutation

10.Shine-Dalgarnosequence

PARTII:MULTIPLE/SINGLECHOICES(2pointseach)

1.Thefollowingmoleculeis

1)25-deoxyadenosine59-phosphate

2)2?-deoxyadenosine

3)dAMP

4)dATP

2.Thestrictnessoftherulesfor44Waston-CrickMpairingderivesfromthe

complementarities___betweenadenineandthymineandbetweenguanineand

cytosine.

1)ofbasestacking

2)ofshape

3)ofhydrogenbondingproperties

4)ofsize

3.WhichofthefollowingstatementscorrectlydescribethedifferencebetweenDNAand

RNA?

1)ThemajorgrooveoftheregularDNAdoublehelicalstructureisrichinchemical

information.

2)RNAcontainsdeoxyriboseanduracil.

3)AllRNAsaresingle-strandedwhileDNAisdouble-stranded.

4)SomeRNAscanfoldupintocomplextertiarystructures,andfunctionas

enzymes.

4.Nucleosomesarethebuildingblocksofchromosomes,whichofthefollowing

statementsareCORRECTindescribingthestructureandfunctionofnucleosome?___

1)Thenucleosomeiscomposedofacorecontainingeighthistoneproteinsandthe

DNA(-147bp)wrappedaroundthem.

2)ThecorehistonesspecificallycontactthemajorgrooveoftheDNA.

3)TheinteractionofDNAwiththehistoneoctamerisverystableandcannotbe

alteredunlessduringDNAreplication.

4)Nucleosomeremodelingbytheactionofenzymessuchashistoneacetylaseis

veryimportantforgeneexpression.

5.WhichofthefollowingstatementsregardinggenomesoflivingorganismisNOT

correct?___

1)Genomesizeisroughlyrelatedtothecomplexityoftheorganism.

2)Thenumberofgenesinagenomecannotexplainthecomplexityoftheorganism.

3)Theaveragenumberofintronspergeneincreaseswiththeorganismcomplexity.

4)Thegenedensity(genes/Mb)increaseswiththeorganismcomplexity.

6.Thefactthatmostaminoacidsarespecifiedbymultiplecodonsisknownas:__

1)The44wobble^^phenomenon.

2)Theuniversalityofthegeneticcode.

3)Codonbias.

4)Theanticodonhypothesis.

5)Theredundancyofthegeneticcode.

7.WhichofthefollowingrepairmechanismsisinvolvedinrepairofthedamagedDNA

withadouble-strandedbreak?

1)Baseexcisionrepair

2)Nucleotideexcisionrepair

3)Translesionrepair

4)RecBCDpathwayrepair

5)Mismatchrepair

8.Whichofthefollowingfactors/elementsregardingtranslationareCORRECT?

1)Ribosomebindingsite(RBS)isessentialforthetranslationinitiationinbacterial

andeukaryoticcells.

2)ThepolyAtailinthe3'endofanmRNApromotestheefficientrecyclingof

ribosomes,andthereforethetranslationalefficiency.

3)RibosomeisabletodiscriminatebetweencorrectlyorincorrectlychargedtRNAs.

4)ThetranslocationfactorEF-GmimicsatRNAmoleculesoastodisplacethe

tRNAboundtotheAsite.

5)Therib