雨课堂学堂在线学堂云《分子生物学（暨南 ）》单元测试考核答案

注：不含主观题第1题单选题(1分)Hydrophobicinteractioninproteinisgivingimportantstabilizationcontributions()Atoproteinssecundary-andtertiarystructureBjusttotheorientationofpolaraminoacidsCtotheproteinsprimarystructureDaftereverypossiblehydrogenbondingareformedEonlyinhydrophobicfaces正确答案：E第2题单选题(1分)Thestructuralmembraneproteinsarecharacterizedincaseofthatthey()Adon'ttransportsmallmoleculesBexistonlybybetasheetsCshowprosteticcarbohydrategroupsonthecytoplasmaticsideDhaveahydrophobictransmembranedomainEconstitueabout10%ofthemembraneproteins第3题单选题(1分)Whenaproteiniscompletelyhydrolyzedwillthefurtheranalyse:()AOnlydetectaminoacidsinSconformationBOftendetectothermoleculesbesidesaminoacidsCNeverdetectmorethan20standardaminoacidsDNeverdetectfewerthan20standardaminoacidsEOnlydetectthe20standardaminoacids第4题单选题(1分)Onecandistinguishprokaryoticchromosomesfromeukaryoticchromosomesbydetermining:()ANucleotidesequenceBChromosome-linkedproteinsCBasecompositionDSecondarystructure第5题单选题(1分)Hyperchromicity(increasedODvalue)resultsfrom:()AIncreasedlightabsorbancebydouble-strandedDNAwhenitisdenaturedBIncreasedlightabsorbancebydouble-strandedDNAwhenitishydrolyzedCIncreasedlightabsorbancebydouble-strandedDNAcontaminatedbyRNADIncreasedlightabsorbancebydouble-strandedDNAwhenitisrenatured第6题单选题(1分)WhichoneofthefollowingisacommonsecondarystructurefoundinRNA?()AadoublehelixBastem-loopCasupercoilDacruciformEnoneofabove第7题单选题(1分)Whichofthefollowingisnotaribonucleoproteincomplex?()ARibosomeBSplicesomeCNucleosomeDRISCEsnoRNP第8题单选题(1分)WhichofthefollowingstatementsisTRUE?()AhydrophobicforcesareduetotheintrinsicattractionbetweenhydrophobicsidechainsBβ-sheetscanbestretchedrelativelymorethanα-helicesCchaperonesincreasetherateofproteindenaturingDβ-sheetsareformedfrominter-chainhydrogenbonding第9题单选题(1分)WhichoneofthefollowingisNOTinvolvedinproteindegradation?()AProteindigestionbyproteases.BLysosomalpathway.CProteinmulti-ubiquitylation.DProteinglycosylation.第10题单选题(1分)Inwaterysolutionsproteinsconformationisdecidedbytwofactors:Amaximumofthenumberofhydrogenbondingand:()AaminimizeaventropybytheformationofawateryshellaroundtheproteinBarotationoffpolaraminoacidresiduesoutagainsttheoutershellofftheproteinCarotationoffhydrophobicaminoacidssidechainstowardsthecentreoftheproteinDminimizeoffhydrophobicinteractionsEmaximizeofioninteraction第11题单选题(1分)WhichofthefollowingcanNOTbeusedinproteinstructureprediction?()Ainsilicomodeling;BX-raycrystallography;CNMR;DYeasttwo-hybrid.第12题单选题(1分)Aproteinwithoutanyinteractionsbetweendifferentresiduesisexpectedtoform:()Aαhelix;Bβstrand;Cβsheet;Drandomcoil;ECoiled-coil.第三单元测试第1题单选题(1分)ThepolarityofDNAchainisrepresentedby:()A3’-5’B1’-6’C1’-3’D2’-3’Enoneoftheabove.第2题单选题(1分)Thekindofnucleicacidthatisrepresentedbyacloverleafmodelis:()AmitochondrialDNABchromosomalDNACRrnaDTrnaEmRNA第3题单选题(1分)Whichhistoneproteinisnotpartofanucleosome?()AH1BH2aCH2bDH3EH4第4题单选题(1分)ThebackboneofaDNAmoleculeis:()AmadeupofsugarsBmadeupofnitrogenousbasesCmadeupofphosphategroupsDmadeupofalternatingphosphateandsugargroupsEmadeupofalternatingsugarsandnitrogenousbase第5题单选题(1分)SupercoilinginlinearDNAhaswhatadvantagefortheeukaryoticcell?()AIthelpstocompactDNAsothatitfitsintothenucleus.BIthelpstoexpandDNAsothatitismoreaccessibletometabolicenzymes.CUnderwoundDNAexertsaforcethathelpsseparatethetwostrandsofDNAduringtranscription.DOverwoundDNAexertsaforcethathelpsseparatethetwostrandsofDNAduringtranscription.Eaandc正确答案：E第6题单选题(1分)Anitrogenousbasethatoccursinadouble-strandDNAinequalquantitieswithguanine:()ADeoxyriboseBRiboseCUracilDCytosineEThymine第7题单选题(1分)WatsonandCrickproposedamolecularstructureormodelofdoublehelicalDNAin1952whichcontainsahelicalturnevery10baseparisandadjacentbasepairs0.34nanometersapart.ThisformofDNAisnowoneofseveralformsknowntoexist.Whichoneofthefollowing

DNAAADNABBDNACZDNADTriplehelicalDNA第8题单选题(1分)ChoosethemoleculardefinitionofagenethatincludesallofDNAelementsthatmaybepartoftheDNAsequenceofagene:()ATheDNAsequenceofageneincludesonlyexons.BTheDNAsequenceofageneincludesonlyexonsandintrons.CTheDNAsequenceofageneincludesexons,intronsandnoncodingregulatorycontrolregions.DTheDNAsequenceofageneincludesexons,introns,noncodingregulatorycontrolregionsandintergenicregions.第9题单选题(1分)ThemaintenanceofDNAmethylationiscatalyzedby:()ADnmt1BDnmt3aCDnmt3bDRNMTEMeCP2.第10题单选题(1分)TheDNAfingerprintingcanbeusedfor:()AindividualsidentificationBdetermineofthelevelofexpressionofaspecifictranscriptCdeterminetheDNA-bindingsiteforatranscriptionfactorDpaternaltestEAandD正确答案：E第11题单选题(1分)BelowisalistoffourstagesinthesynthesisofaproteinfromtheDNAcode.(1)ThebasesequenceonDNAistranscribed;(2)AnticodonsontransferRNApairwithcodonsonmessengerRNA;(3)MessengerRNAleavesthenucleus;(4)Peptidebondsformbetweenadjacentaminoacids.Whichofthefollowingisthecorrectsequenceofthesesteps,fromfirsttolast?()A4,2,1,3B3,2,1,4C1,3,2,4D2,1,3,4第12题单选题(1分)OnemRNAcodonfortheaminoacidlysineisAAG.Howmanylysinemoleculesarepresentinthepolypeptide,containing7aminoacids,codedbytheDNAtemplateCTGAAGTCCAAGTCAAGTTCC?()A0B1C2D3第13题单选题(1分)Ofthefollowingfeatures,whichisacharacteristicofprokaryoticcells?()ACircularDNABEndoplasmicreticulumCMitochondriaDNucleolus第14题单选题(1分)WhichofthefollowingisanaccuratestatementconcerningthedifferencesbetweenDNAandRNA?()ARNAisusuallydouble-stranded,butDNAisusuallysingle-stranded.BRNAhasthesugardeoxyribose,butDNAhasthesugarribose.CRNAcontainsthreedifferentnucleotides,butDNAcontainsfourdifferentnucleotides.DRNAlacksthebasethymine(whichisfoundinDNA)andhasuracilinstead.第15题单选题(1分)TheDNAsequenceofacodoninagenewaschangedfromAATtoAAC.Thistypeofmutationiscalleda():()ApointmutationBinsertionmutationCdeletionmutationDframeshiftmutationEtruncationmutation第四章单元测试第1题判断题(1分)DuringDNAreplication,theDNAtemplatestrandisreadin5'-3'directionwhiletheDNAtemplatestrandisreadin3'-5'directionduringtranscription.()第2题判断题(1分)ThereisnoRNAprimersynthesisrequiredforsynthesisoftheleadingstrandduringrollingcirclereplication.()第3题判断题(1分)AparentcircularDNAmoleculeyieldtwodaughtercirclesinthetareplication.()第4题判断题(1分)TheinitiationofDNAreplicationoccursataspecificbasesequencecalled“ori”.()第5题判断题(1分)ReplicationoriginsareuniqueDNAsegmentsthatcontainmultipleshortrepeatedsequences.()第6题判断题(1分)ReplicationoriginsusuallycontainanAT-richstretch.()第7题判断题(1分)Aeukaryoticchromosomehasoneoriginofreplication.()第8题单选题(1分)Allrepliconsmust:()AbecontainedwithinthenucleusBbecomposedofcircularDNAorRNACbecomposedofDNADhaveanoriginofreplicationEcarryageneforDNApolymerase第9题单选题(1分)SSBprotein:()AunwindsthedoublehelixinfrontofthereplicationforkBattachesthesyntheticsubunitofDNApolymerasetotheDNACinsertstheprimerforDNAsynthesisDkeepstheDNAsinglestrandedatthereplicationforkEsealsthenicksbetweenOkazakifragments第10题单选题(1分)Duringrollingcirclereplication:()AManyinterlockingcirclesofDNAaremadeBTwooriginsofreplicationareusedCAsinglestrandisnickedwhenreplicationstarts;DAcircularRNAprimerisusedENoneoftheaboveistrue第11题判断题(1分)DnaBisahelicaseandDnaGisapimase.()第12题单选题(1分)Duringrollingcirclereplication,whichofthefollowingisfalse?()AThereisnoRNAprimersynthesisrequiredforsynthesisoftheleadingstrand.BTheleadingstrandiscovalentlylinkedtotheparentaltemplateusedforlaggingstrandsynthesis.CNolaggingstrandissynthesized.DThetemplateusedforsynthesisofthelaggingstrandremainsintact.第13题单选题(1分)Telomeraseisaribonucleoproteincomplexthat:()AsynthesizesDNAintheabsenceofaDNAorRNAtemplate.BsynthesizesDNAuseaDNAtemplatethatispartoftheribonucleoproteincomplex.CsynthesizesDNAuseaRNAtemplatethatispartoftheribonucleoproteincomplex.DsynthesizesDNAusingribosomalRNAastemplate.第14题单选题(1分)Telomeresareshortenedslightlyaftereveryroundofreplicationbecause:()ATelomerasecutsoffseveral6-bprepeats.BThegapcreatedbyremovaloftheRNAprimerattheveryendofthechromosomecannotbefilledin.CThegapcreatedbyremovaloftheRNAprimerinthecenterofthechromosomecannotbefilledin.DOlderchromosomesaremorefragileandtheendsbreakoffmorefrequently.ETelomeraseisonlyfunctionalincancercells.第15题单选题(1分)WhichtypeofenzymemakesatransientbreakinbothDNAduplexstrandsandthentransportsanothersegmentofaDNAmolecule(orseparatemoleculeentirely)throughthebreakandresealstheseveredstrands?()AtopoisomeraseIBtopoisomeraseIICtopologicaseIDtopologicaseIIEisomeraseI第五章单元测试第1题单选题(1分)RNA聚合酶I的功能是()A转录tRNA和5SrRNAB转录蛋白质基因和部分snRNA基因C只转录rRNAD转录多种基因第2题单选题(1分)有关RNA转录合成的叙述,其中错误的是()A转录过程RNA聚合酶需要引物B转录时只有一股DNA作为合成RNA的模板CRNA链的生长方向是5’-3’D所有真核生物RNA聚合酶都不能特异性地识别启动子第3题单选题(1分)关于外显子与内含子的叙述,正确的是()A外显子是不表达成蛋白质的序列B内含子在基因表达过程中不被转录C内含子在基因组中没有任何功能D真核生物的外显子往往被内含子隔开第4题单选题(1分)大肠杆菌转录生成mRNA是()AhnRNAB半衰期普遍比真核生物mRNA长C只能编码一个多肽D多顺反子第5题单选题(1分)mRNA的序列是ACUGAGCU,那么通过反转录合成的cDNA的序列应该是()A5’TGACTCGA3’B5’AGCTCAGT3’C5’AGCUCAGU3’D5’ACTGAGCT3’第6题单选题(1分)以下关于原核生物RNA聚合酶的核心酶的叙述,哪一项是正确的()A核心酶可以与DNA结合,但不能催化以DNA为模板合成RNAB核心酶能够在正确的位置起始转录,但效率比RNA聚合酶全酶低C核心酶能催化以DNA为模板合成RNA,但不能在正确的位点起始转录D核心酶不能与DAN模板结合第7题单选题(1分)以下有关大肠杆菌转录的叙述,哪一个是正确的()。A-35区和-10区序列间的间隔序列是保守的B-35区和-10区序列的距离对于转录效率非常重要C转录起始位点后的序列对于转录效率不重要D-10区序列通常正好位于转录起始位点上游10bp处第8题判断题(1分)细菌DNA依赖的RNA聚合酶由五个亚基组成,亚基与转录启动有关。()第9题判断题(1分)RNA聚合酶催化的反应无需引物,也无校对功能。()第10题判断题(1分)在真核生物中,所有rRNA都是由RNA聚合酶Ⅱ转录的。()第11题判断题(1分)转录的起始点就是RNA聚合酶与模板DNA结合的第一个核苷酸的位置。()第12题判断题(1分)真核生物RNA聚合酶和原核生物RNA聚合酶都可以独立启动基因转录。()。第六章单元测试第1题单选题(1分)Whichofthefollowingisnotanessentialcomponentoftheeukaryoticinitiationstageoftranslation?()A40SribosomeBeIF2CGTPDN-formylmethionyl-tRNAfMet第2题单选题(1分)ThebacterialShine-DalgarnomRNAsequenceisspecificallyrecognizedby:()AproteinS5ofthe30Ssubunit.BN-formylmethionyl-tRNAfMet.Cthe23SrRNAofthe50Ssubunit.Dthe16SrRNAofthe30Ssubunit.第3题单选题(1分)Afunctionofwhichinitiationfactoristopreventprematurejoiningofthelargeandsmallribosomalsubunits?()AeIF1AineukaryotesandIF-1inbacteriaBeIF2ineukaryotesandIF-2inbacteriaCeIF5ineukaryotesandIF-3inbacteriaDeIF3ineukaryotesandIF-3inbacteria第4题单选题(1分)Whichofthefollowingisnottrueoftheformationofaeukaryotictranslationinitiationcomplex?()AeIF4Fbindstothe5'capofthemRNA.BeIF2bindstotheAsitetoblockthebindingoftheinitiatingtRNA.CAtleasttwoGTPmoleculesarehydrolyzedperinitiationevent.DeIF1,eIF1A,eIF2,andeIF3aredisplacedbeforethe60Ssubunitjoinsthe40Ssubunit.第5题单选题(1分)Whichofthefollowingistrueofbacterialtranslationtermination?()ATheribosomecontinuestosynthesizeproteinuntilitreachesthe3'endofthemRNA.BTerminationrequiresthedegradationoftheribosome.CTerminationissignaledbythepresenceofastopcodoninthemRNA.第6题单选题(1分)Whichoneofthefollowingstatementsisafeatureofthewobblehypothesis?()AAnaminoacid-specifictRNAmoleculecanrecognizeonlyonecodon.BThewobbleoccursonlyinthethirdbaseoftheanticodon.CWheninosine(I)isthefirstnucleotideofananticodon,atleastthreedifferentcodonsforthesameaminoacidcanberecognized.DtRNAmoleculescanrecognizecodonsthatspecifytwodifferentaminoacids.第7题单选题(1分)Afterdeterminingthatthegeneticcodeisreadintripletcodons,thequestionaroseastowhetherthecodewasoverlappingornonoverlapping.Ifthecodewasoverlapping,achangeinonenucleotidecouldresultinachangeinhowmanyaminoacids?()AoneBtwoCthreeDfive第8题单选题(1分)Whichofthefollowingstatementsaboutthebacterialribosomeisnottrue?()AThe70Sribosomeisacomplexof50Sand30Ssubunits.BTheentireproteincomponentofthe30Ssubunitisasinglepolypeptidechain.CEachribosomalsubunitcontainsatleastoneRNAmolecule.DAnrRNAmolecule,ratherthanprotein,catalyzespeptidebondformation.第9题单选题(1分)Whichofthefollowingdescribesanaccurateorderofeventsintranslation?()ARibosomaltranslocationoccursbeforethefirstaminoacyl-tRNAmoleculebindstothesmallsubunit.BInitiationoftranslationoccursonlyafterthesmallsubunitdissociatesfromthemRNA.CThelargesubunitoftheribosomebindsthemRNAbeforethesmallsubunit.DThefirstaminoacyl-tRNAmoleculebindstothesmallsubunitbeforethelargesubunitbinds.第10题单选题(1分)WhichsiteontheribosomeisneveroccupiedbyatRNAlinkedtoanascentpolypeptidechain?()AtheAsiteBthePsiteCtheEsite第11题单选题(1分)ThebacterialShine-DalgarnomRNAsequenceisspecificallyrecognizedby:()AproteinS5ofthe30Ssubunit.BN-formylmethionyl-tRNAfMet.Cthe23SrRNAofthe50Ssubunit.Dthe16SrRNAofthe30Ssubunit.第七章单元测试第1题单选题(1分)Whichofthefollowingdescribesafeatureofaminoacidstructure?()AThecentraloralpha-carbonoftheaminoacidisbondedtothreeothergroups.BEachaminoacidwillhaveeitheranalpha-aminogrouporanalpha-carboxylgroup.CTheRgroupsofaminoacidswillvaryinstructure,size,electricalcharge,andhydrophobicity.DThealpha-aminoandalpha-carboxylgroupsarefrequentlymodifiedbyphosphorylation.EInmostcases,thecentraloralpha-carbonoftheaminoacidisbondeddirectlytoahydroxylgroup.第2题单选题(1分)WhichofthefollowingaminoacidshasanonpolarthioetherRgroup?()AcysteineBserineCtryptophanDmethionineENoneofthechoicesgiveniscorrect.第3题单选题(1分)Theflexibilityofthepolypeptidebackbone:()AallowsmaximumrotationoftheunbranchedRgroups.Ballowsresonancebetweentransandcisconfigurations.Cislimitedbytheresonancebetweenthealphacarbonandcarboxyloxygen.Dislimitedbyresonancebetweenthecarboxyloxygenandamidenitrogen.EisdeterminedbybalancebetweenpolarandnonpolarRgroups.第4题单选题(1分)Whichofthefollowingaminoacidswouldmostlikelynotbefoundinanalfahelix?()AmethionineBlysineCphenylalanineDprolineEglutamine第5题单选题(1分)Whichofthefollowingaminoacidsis/arenegativelychargedatphysiologicalpH?()AserineBaspartateCglutamateDserine,aspartate,andglutamateEaspartateandglutamate正确答案：E第6题单选题(1分)Analfahelixisformedbyhydrogenbondsbetween:()AnonpolarandpolarRgroups.BpositivelychargedandnegativelychargedRgroups.Cthecarbonyloxygenandtheamidenitrogenofalternateaminoacids.Dthecarbonyloxygenandtheamidenitrogenofeverythirdaminoacid.Ethecarbonyloxygenandtheamidenitrogenofeveryfourthaminoacid.正确答案：E第7题单选题(1分)Parallelbetasheetsdifferfromantiparallelbetasheetsbecause:()Aneighboringaminoacidsareononeratherthanbothsidesofthesheet.Blargearomaticgroupsareonlyallowedwithparallelsheets.Cparallelsheetscanformbetweenasinglepolypeptide.DtheN-to-Corientationofalltheβstrandsarealigned.Ehydrogenbondsarecrucialforstability.第8题单选题(1分)Approximatelyone-thirdofapolypeptidechainconsistsofreverseturnsbecause:()Aturnsincreasestability.Bturnsarethesiteofsubstratebinding.Cturnsallowapolypeptidetoassumeaglobularconfiguration.Dalfahelicesarestabilizedbyturns.Ebetasheetsarestabilizedbyturns.第9题单选题(1分)Domainsofaproteincanbestbedescribedas:()Atheuniquesequencesofeachparticipatingprotomer.Bfunctionalcomponentsofaprotein.Cindependentlyfoldingunitsofapolypeptidechain.DNoneoftheanswersprovidediscorrect.EAlloftheanswersprovidedarecorrect.正确答案：E第10题单选题(1分)Whichofthefollowingstatementsaboutquaternarystructureisnotcorrect?AAhomotrimerconsistsofthreeidenticalprotomers.BIdenticalpolypeptidescancreateafunctionalprotein.CAribosomecanbeconsideredanoligomer.DAllfunctionalproteinshaveaquaternarystructure.ELessDNAisrequiredtocodefora70,000molecularweighthomotrimerthana70,000molecularweighthomodimer.第11题单选题(1分)Imagineacellularproteincomposedof3000aminoacidresiduesinonecontinuouspolypeptidechain.Thisproteinisalmostcertainly()Aextracellular.Bglobular.Cmultidomain.Dcomposedofmostlyα-helicalregions.Eintrinsicallydisordered.第12题单选题(1分)Phosphorylationofaproteinbyaproteinkinase()Aaddstwopositivechargestotheprotein.Bactivatestheprotein.Cdeactivatestheprotein.Dcancreateabindingsiteforotherproteins.ErequiresthehydrolysisoftwomoleculesofATPperphosphorylatedresidue.第八章单元测试第1题单选题(1分)Whichofthefollowingstatementsdescribesastepintheregulationofthelacoperon:()AAcyclicAMP-CAPcomplexbindstotheCAPsite.BTherepressorbindstoCAPtoformaninactiverepressor.CCyclicAMPcompeteswiththerepressorforbindingtotheoperator.DTherepressorundergoesaconformationalchangeuponbindingcyclicAMP.第2题单选题(1分)Regulationofβ-galactosidasesynthesisis()Aunderneitherpositivenornegativecontrol.Bunderonlypositivecontrol.Cunderonlynegativecontrol.Dunderbothpositiveandnegativecontrol.Enoneoftheabove.第3题单选题(1分)Allthefollowingmutationscanresultinadeductionofβ-galactosidasesexcept:

AAmutationinadenylatecyclase.B

AmutationinCAP.

CAmutationintheCAPsiteinthelaccontrolregion.DAmutationintherepressorbindingsiteintheoperator.第4题单选题(1分)WhichofthefollowingisNOTafeatureofeukaryoticgeneexpression?()ApolycistronicmRNAsareveryrareBmanygenesareinterruptedbynon-codingDNAsequencesCRNAsynthesisandproteinsynthesisarecoupledasinprokaryotesDmRNAisoftenextensivelymodifiedbeforetranslationEmultiplecopiesofnucleargenes,andpseudogenescanoccur第5题单选题(1分)RNAeditingsitesintrypanosomemitochondriaareselectedby()AcomplementaryDNAsBRNAsecondarystructureCconservedsequencesflankingtheeditingsitesDguideRNAsEnoneoftheabove第6题单选题(1分)Whichofthefollowingislikelytobethefunctionofintron?()Asourcesofnon-codingRNABregulatinggeneexpressionCcontributionofgenomeevolutionDregulatingRNAtranspotEalloftheabove正确答案：E第7题单选题(1分)Whichofthefollowingcanbeusedasanalternativestartcodonoftranslation?()AGCGBCGGCUUGDAUUEGUG.正确答案：E第8题单选题(1分)ProteinsbindtomethylatedCpGarefoundtorecruithistonedeacetylasesindicatedthat:()ADNAmethylationsaremediatedbyhistonedeacetylases;BhistoneacetylationsaremediatedbyDnmt;CAcorrelationbetweenDNAmethylationandhistonemodification;DDNAmethylationinducedgenesilencingisindependentofhistonemodification;EHistonemodificationaffectschromatinstructure.第9题判断题(1分)Themostcommonformofgeneexpressionregulationinbothbacteriaandeukaryotesistranslationalcontrol.()第10题判断题(1分)Themechanismsofplasmidcopynumberliewiththeplasmidratherthanthehostgenome.()第11题判断题(1分)Theregulationofthelactoseoperonbythelacrepressorisanexampleofpositiveregulationoftranscription.()第12题判断题(1分)TheShine-DalgarnosequenceinmRNAsbasepairstoaCCUCCUsequenceofE.coli16SrRNA.()第九章单元测试第1题单选题(1分)一个碱基的插入或缺失所造成的移码突变,最有可能由下列哪项因素引起()。A5-溴尿嘧啶B亚硝酸C原黄素D2-氨基嘌呤第2题单选题(1分)在DNA复制时插入一对碱基,会引起三联体密码()。A替换B倒位C缺失D移码第3题单选题(1分)碱基C突变为T称为()。A颠换B转换C移码D全部都不对第4题单选题(1分)在一个突变过程中,一对额外的核苷酸插入DNA内,会有什么样的结果()。A完全没有蛋白质产物B产生的蛋白质有一个氨基酸发生了变化C产生的蛋白质有三个氨基酸发生了变化D产生的蛋白质中,插入部分以后的大部分氨基酸都发生了变化第5题单选题(1分)某一编码子突变成UAG,这种突变称为()。A无义突变B错义突变C同义突变D抑制突变第6题判断题(1分)基因突变具有多方向性,一个基因可以突变成为生理功能和性状表现各不相同的多个复等位基因。()第7题判断题(1分)基因突变一般是可逆的,而染色体结构变异则一般是不可逆的。()第8题判断题(1分)紫外线和电离辐射所引起的损伤都可以被修复,许多化学诱变剂引起的损伤也能被修复。()第9题判断题(1分)镰刀型细胞贫血病是由于血红蛋白分子中的β链发生突变所致,这种突变属于移码突变。()第10题判断题(1分)亚硝酸和烷化剂是有效的诱变剂,它们的作用方式是改变DNA的化学结构,引起转换或颠换。()第11题判断题(1分)突变基因再次发生突变,使原基因的功能得到恢复,这类突变称为回复突变。()第12题判断题(1分)DNA的错配修复发生在新生链被甲基化之前。()第十章单元测