分子生物学智慧树知到课后章节答案2023年下中南大学

分子生物学智慧树知到课后章节答案2023年下中南大学中南大学

第一章测试

核苷中糖分别与嘧啶和嘌呤的哪个位点结合？（）。

A:嘧啶的1号位和嘌呤的9号位B:嘧啶的1号位和嘌呤的1号位C:嘧啶的9号位和嘌呤的1号位D:嘧啶的9号位和嘌呤的9号位

答案:嘧啶的1号位和嘌呤的9号位

在DNA或RNA合成中，三磷酸核苷除了一个磷酸基团进入新合成的核酸链以外，另外两个磷酸以（）形式离开。

A:焦磷酸B:都不对C:单个磷酸分子D:与蛋白质结合

答案:焦磷酸

在真核生物基因组中DNA甲基化能（）

A:增强或者抑制基因活性，视具体基因而定B:对基因活性没有影响C:增强基因活性D:抑制基因活性

答案:抑制基因活性

在碱性条件下，DNA和RNA分别会发生的是（）

A:变性，分解B:分解，变性C:分解，分解D:变性，变性

答案:变性，分解

Tmisafunctionofthe（

）contentofDNAsample,andrangesfrom80℃to100℃fordifferentDNAmolecules.

A:G+TB:G+CC:A+GD:A+C

答案:G+C

第二章测试

Asawhole,theE.colichromosomeispositivelysupercoiled.（）

A:对B:错

答案:错

Ineukaryoticchromosomes,morethan____ofthemassofchromatinisprotein.（）

A:60%B:30%C:50%D:40%

答案:50%

Thenucleosomesarewoundintoleft-handedhelix,formasolenoid,witharound____nucleosomesperturn.（）

A:6B:4C:3D:5

答案:6

5`-CG-3`sequenceinmammalianDNAarenormallymethylatedonthe____.（）

A:CandGB:GC:CD:CorG

答案:C

DispersedrepetitiveDNAisrefertomost____DNA.（）

A:highlyrepetitiveB:NoneoftheaboveC:uniqueD:moderatelyrepetitive

答案:moderatelyrepetitive

第三章测试

TheE.colioriCcontains____9bpbindingsitesfortheinitiatorproteinDnaA.（）

A:5B:6C:4D:3

答案:4

IntheE.coli,bothleadingandlaggingstrandprimersareelongatedby_____holoenzyme.（）

A:DNApolymeraseⅠB:DNApolymeraseⅢC:DNApolymeraseⅡD:DNApolymeraseⅣ

答案:DNApolymeraseⅢ

判断对错：Definedreplicationoriginsequenceshavenotbeenisolatedfrommammaliancells.（）

A:对B:错

答案:对

TelomeraseisareversetranscriptasethatcarriesitsownRNAmolecule(about（

）nt).

A:100B:200C:150D:50

答案:150

Theunlimitedproliferativecapacityofmanycancercellsisassociatedwith（

）oftelomeraseactivity.

A:reactivationorinactivationB:inactivationC:reactivationD:Noneoftheabove

答案:reactivation

第四章测试

What'stheChinesefornonsensemutations?（）

A:无义突变B:沉默突变C:都不是D:错义突变

答案:无义突变

ThemostimportantformcausingDNAdamageis（

）whichproducespyrimidinedimersfromadjacentpyrimidinebases.

A:X-raysB:VisiblelightC:γ-raysD:UVlight

答案:UVlight

______oftheDNAafterreplicationallowsthedaughterstrandtobedistinguishedfromtheparentalstrand.（）

A:AcetylationB:MethylationC:HemimethylationD:Phosphorylation

答案:Hemimethylation

HomologousrecombinationisalsoimportantforDNArepair.Thismechanismhasalsobeencalled_____.（）

A:replicationrepairB:NoneoftheaboveC:pre-replicationrepairD:post-replicationrepair

答案:post-replicationrepair

判断：Thegeneintowhichthetransposoninsertsisusuallyactivated,andgenesbetweentwocopiesofatransposoncanbedeletedbyrecombinationbetweenthem.（）

A:对B:错

答案:错

第五章测试

Inthetranscription,（

）mayalsobecalledthetemplatestrand.

A:antisensestrandB:singlestrandC:doublestrandD:sensestrand

答案:antisensestrand

判断：Inprokaryotes,transcriptionandtranslationaredynamicallycoupled,asthelatterstartsbeforetheformeriscomplete.（）

A:对B:错

答案:对

Followingsuccessfultranscriptioninitiation,the（

）subunitofE.coliRNApolymeraseisreleasedtoformaternarycomplex(threecomponents)ofpolymerase-DNA-nascentRNA,whichisresponsibleforRNAchainelongation.

A:β’B:αC:βD:σ

答案:σ

判断：NoprimerisneededforRNAsynthesis.（）

A:错B:对

答案:对

Somegenescontainterminatorsequenceswhichrequireanadditionalproteinfactor,（

）,forefficienttranscriptiontermination.

A:σB:αC:ρD:β

答案:ρ

第六章测试

Thelactose(lac)operonconsistsof（

）structuralgenes.

A:twoB:oneC:fourD:three

答案:three

Thelacrepressorismadeupof（

）identicalproteinsubunits..

A:threeB:fourC:oneD:two

答案:four

Thetrprepressorisadimerwhichinteractswiththetrpoperatoronlywhenitiscomplexedwith________.（）

A:tryptophanB:lysineC:leucineD:alanine

答案:tryptophan

Thetrpoperonencodes_____structuralgenesinvolvedintryptophanbiosynthesis.（）

A:threeB:fourC:sixD:five

答案:five

TheleadersequenceofthetrpoperonRNAcontainsfourregionsofcomplementarysequencewhichcanformdifferentbase-pairedRNAstructures.Thesearetermedsequences1,2,3and4.Theattenuatorhairpinistheproductofthebasepairingof______.（）

A:sequences3and4B:sequences1and4C:sequences1and2D:sequences2and3

答案:sequences3and4

第七章测试

Ineukaryoticcell,（）islocatedinthenucleoplasm.Itisresponsibleforthesynthesisoftheprecursorsof5SrRNA,tRNAsandothersmallnuclearandcytosolicRNAs.

A:RNApolymeraseIB:RNApolymeraseIIC:RNApolymeraseIIID:RNApolymeraseⅣ

答案:RNApolymeraseIII

Ineukaryoticcell,thelargestsubunitofRNApolymeraseIIhasa_____aminoacidrepeatattheCterminuscalledthecarboxy-terminaldomain(CTD).（）

A:fourB:fiveC:sevenD:six

答案:seven

RNAPolⅢtranscribes5SrRNAcomponentofthesmallribosomalsubunit,whichistheonlyrRNAsubunittobetranscribedseparately.

A:错B:对

答案:错

SomeRNAPolIIpromotershaveneitheraTATAboxnoraninitiatorelement.Thesegenesaregenerallytranscribedathighrates,andinitiationoftranscriptionmayoccuratdifferentstartsitesoveralengthofupto200bp.

A:对B:错

答案:错

（）bindstoTATAbox.ItisamultiproteincomplexofTBPandTAFⅡs(TBP-associatedfactors).

A:TFⅡDB:TFⅡAC:TFⅡCD:TFⅡB

答案:TFⅡD

第八章测试

（

）isNOTaDNA-bindingdomainofeukaryotictranscriptionfactor。

A:ZincfingerdomainB:Glutamine-richdomainC:BasicdomainD:Helix-turn-helixdomain

答案:Glutamine-richdomain

WhichoneofthefollowingisaDNA-bindingdomainofeukaryotictranscriptionfactor?（）

A:LeucinezipperB:Glutamine-richdomainC:ZincfingerdomainD:Proline-richdomain

答案:Zincfingerdomain

Whichoneofthefollowingisadimerizationdomainofeukaryotictranscriptionfactor?（）

A:ZincfingerdomainB:Proline-richdomainC:LeucinezipperD:Helix-turn-helixdomain

答案:Leucinezipper

Whichoneofthefollowingisatranscriptionactivationdomainofeukaryotictranscriptionfactor?（）

A:Helix-turn-helixdomainB:Glutamine-richdomainC:ZincfingerdomainD:Basicdomain

答案:Glutamine-richdomain

SP1contains（

）zincfingermotifsandtwoglutamine-richtransactivationdomains.

A:sixB:fourC:fiveD:three

答案:three

第九章测试

Inthenucleolusofeukaryotes,RNApolymeraseI(RNAPolI)transcribestherRNAgenes,whichusuallyexistintandemrepeats,toyieldalong,singlepre-rRNAwhichcontainsonecopyeachofthe18S,5.8Sand28Ssequences

A:错B:对

答案:对

许多真核生物前tRNA是由内含子以及额外的5'-和3'-核苷酸合成的，所有这些都在加工过程中被去除。（）

A:对B:错

答案:对

SeveralbiochemicalreactionscanbecarriedoutbyRNAenzymes(ribozymes).（）

A:对B:错

答案:对

ProcessingofeukaryotichnRNAinvolvesseveralevents（）

A:splicingB:methylationC:5’-cappingD:3’-cleavageandpolyadenylation

答案:splicing;methylation;5’-capping;3’-cleavageandpolyadenylation

Thissplicingreactionoccursinthenucleusandrequirestheintrontohave:（）

A:anAG-3’B:a5’-GUC:amethylationsiteD:abranchpointsequence

答案:anAG-3’;a5’-GU;abranchpointsequence

第十章测试

（

）isthesimpletransferofaclonedfragmentofDNAfromonevectortoanother.

A:CloningB:NoneoftheaboveC:SubcloningD:Precloning

答案:Subcloning

Sinceplasmidsare（

）E.colichromosomalDNA,theycanbeseparatedfromthelatterbyphysico-chemicalmethods,suchasalkalinelysis.

A:smallerorlargerthanB:smallerthanC:equaltoD:largerthan

答案:smallerthan

（

）restrictionenzymescutDNAattherecognitionsiteandforthisreasonaremostoftenusedinscientificexperimentation.

A:Type4B:Type3C:Type2D:Type1

答案:Type2

Treatmentofthelinearvectormoleculewith（

）willremovethe5’-phosphatesandrenderthevectorunabletoligateintoacirclewithoutaninsertedtarget,soreducingtheproportionofrecreatedvectorinthemixture.

A:restrictionenzymeB:T4DNAligaseC:DNApolymeraseD:alkalinephosphatase

答案:alkalinephosphatase

TheE.colicellscanbemadecompetenttotakeupplasmidDNAbytreatmentwith（）

A:K+B:Na+C:Cu2+D:Ca2+

答案:Ca2+

第十一章测试

5’-Endlabelingisperformedusing（）toaddaradioactivephosphatetonucleicacidswithafree5’-hydroxylgroup,whichcanbecreatedbydephosphorylationusingalkalinephosphatase.

A:T4DNAligaseB:DNApolymeraseC:restrictionenzymesD:polynucleotidekinase

答案:polynucleotidekinase

InSouthernblotting,thewashingstepshouldbecarriedoutat（）℃belowTmoftheprobeandtargetsequences.

A:10B:12C:6D:5

答案:12

Sangerchain-terminationmethodofDNAsequencinguses（）toterminateenzymicallysynthesizedcopiesofatemplate.

A:NTPsB:dNTPsC:ddNTPsD:Noneoftheabove

答案:ddNTPs

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