分子生物化学习题册.pdfVIP

分⼦⽣物化学习题册

Chapter2GenesandChromosomes

Questions:

1.Whatisdifferentbetweengeneclusterorgenefamily?

2.CanyouexplainwhyAdoesnotbase-pairwithC,andwhyTdoesnotbase-pairwithG?

3.ThechemicalstructureofUissimplerthanT.So,weunderstandwhyRNAusesU,

insteadofT.AcanpairwithUasperfectlyaswithT.However,whydoesDNAuseT?

WhydoseDNAchooseamorecomplexbase?

4.Whydowechoosethoseorganismsasmodelorganisms?

5.IsthejunkDNArealjunk?

6.WhatisKlenowfragment?

7.IsDNAreplicationconservativeorsemiconservative?

8.Insemiconservativereplication,whatfractionoftheDNAconsistsofoneoriginalparent

strandandonedaughterstrandafter1,2,and3roundsofrepocation?

9.InwhichmodeofreplicationdoesaparentcircularDNAmoleculeyieldtwodaughter

circles?

10.Inwhichmodeofreplicationdoesaparentcirclegenerateacirclewithalinearbranch?

11.NamethreeenzymaticactivitiesofDNApolymeraseI.

MultipleChoice:

(1)Thenumberofrepliconsinatypicalmammaliancellis?

A40-200

B400

C1000-2000

D50000-100000

(2)Inprokaryotes,thelaggingstrandprimersareremovedby?

A3’-5’exonuclease

BDNAligase

CDNApolymeraseⅠ

DDNApolymeraseⅢ

(3)TheessentialinitiatorproteinattheE.coliorigunofreplicationis?

ADnaA

BDnaB

CDnaC

DDnaE

(4)WhichphasewouldacellenterifitwasstarvedofmitogensbeforetheRPoint?

AS

BG1

CG2

DG0

(5)Whatisimportantforaprokaryoticplasmidtoreplicateinyeastcell?

AORC

BCDK

CARS

DRNA

(6)Inmethyl-directedmismatchrepairinE.coli,thedaughterstrandcontainingthe

mismatchedbaseisnickedby?

AMutHendonuclease

BUvrAB

Cendonuclease

CAPendonuclease

D3’-5’exonuclease

(7)WhichofthefollowingcorrectlydescribesA-DNA?

AAright-handedantiparalleldoublehelixwith10bp/turnandbaseslyingperpendicular

tothehelixaxis.

BAleft-handedantiparall