中科院分子生物学试题库题库4.docx

中科院分子生物学试题库题库4.docx

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中科院分子生物学试题库题库4

GLOSSARY

AbundanceofanmRNAistheaveragenumberofmoleculespercell.

AbundantmRNAsconsistofasmallnumberofindividualspecies,eachpresentinalargenumberofcopiespercell.

Acceptorsplicingsite—seerightsplicingjunction.

Acentricfragmentofachromosome（generatedbybreakage）lacksacentromereandislostcelldivision.

Acrocentricchromosomehasthecentromerelocatedneareroneendthantheother.

Activesiteistherestrictedpartofaproteintowhichasubstratebinds.

Alleleisoneofseveralalternativeformsofageneoccupyingagivenlocusonachromosome.

Allelicexclusiondescribestheexpressioninanyparticularlymphocyteofonlyoneallelecodingfortheexpressedimmunoglobulin.

Allostericcontrolreferstotheabilityofaninteractionatonesiteofaproteintoinfluencetheactivityofanothersite.

Alufamilyisasetofdispersed,relatedsequences,each～300bplong,inthehumangenome.TheindividualmembershaveAlucleavagesitesateachend（hencethename）.

Alu-equivalentfamilyisthesetofsequencesinamammaliangenomethatisrelatedtothehumanAlufamily.

α-AmanitinisabicyclicoctapeptidederivedfromthepoisonousmushroomAmanitaphalloides;itinhibhitstranscriptionbycertaineukaryoticRNApolymerases,especiallyRNApolymeraseII.

AmbercodonisthenucleotidetripletUAG,oneofthreecodonsthatcauseterminationofproteinsynthesis.

AmbermutaiondescribesanychangeinDNAthatcreatesanambercodonatasitepreviouslyoccupiedbyacodonrepresentinganaminoacidinaprotein.

AmbersuppressorsaremutantgenesthatcodefortRNAswhoseanticodonshavebeenalteredsothattheycanrespondtoUAGcodonsaswellasorinsteadoftotheirpreviouscodons.

Aminoacyl-tRNAistransferRNAcarryinganaminoacid;thecovalentlinkageisbetweentheNH2groupoftheaminoacidandeitherthe3’-or-2’-OHgroupoftheterminalbaseofthetRNA.

Aminoacyl-tRNAsynthetasesareenzymesresponsibleforcovalentlylinkingaminoacidstothe2’or3’-OHpositionoftRNA.

Amphipathicstructureshavetwosurfaces,onehydrophilicandonehydrophobic.Lipidsareamphipathic;andsomeproteinregionsmayformamphipathic;andsomeproteinregionsmayformamphipathichelices,withonechargedfaceandoneneutralface.

Amplificationreferstotheproductionofadditionalcopiesofachromosomalsequence,foundasintrachromosomalorextrachromoxomalDNA.

Anchoragedependencedescribestheneedofnormaleukaryoticcellsforasurfacetoattachtoinordertogrowinculture.

Aneuploidchromosomeconstitutiondifferesfromtheusaldiploidconstitutionbylossorduplicationofchromosomesorchromosomalsegments.AnnealingisthepairingofcomplementarysinglestrandsofDNAtoformadoublehelix.

Antibodyisaprotein（immunoglobulin）producedbyBlymphocytecellsthatrecognizesaparticularforeign‘antigen,’andthuswtriggerstheimmuneresponse.

AnticodingstrandofduplesDNAisusedasatemplatetodirectthesynthesisofRNAthatiscomplementarytoit.

Antigenisanymoleculewhoseentryintoanorganismprovokessynthesisofanantibody（immunoglobulin）.

Antiparallelstrandsofthedoublehelixareorganizedinoppositeorientation,sothatthe5’endofonestrandisaligenedwiththe3’endoftheotherstrand.

AntiterminationproteinsallowRNApolymerasetotranscribethroughcertainterminatorsites.

ApendonucleasesmakeincisionsinDNAonthe5’sideofeitherapurinicorapyrimidincsites.

ApoinducerisaproteinthatbindstoDNAtoswitchontranscriptionbyRNApolymerase.

Archebacteriacompriseaminorlineofprokaryotes,andmayhaveintronsinthegenome.Ascusofafunguscontainsatetradoroctadofthe（haploid）spores,representhingtheproductsofasihnglemeiosis.

attstiesarethelocionaphageandthebacterialchromosomeatwhichrecombinationintegratesthephageinto.orexcisesitfrom,thebacterialchromosome.

Attenuationdescribestheregulationofterminationoftranscriptionthatisinvolvedincontrollingtheexpressionofsomebacterialoperons.

Attenuatoristheterminatorsequenceatwhichattenuatiojoccurs.

Autogenousconhtroldescribestheactionofageneproductthateitherinhibits（negativeautogenouscontrol）oractivates（positiveautogenouscontrol）expressionofthegenecodingforit.

Autonomouscontrollingelementinmaizeisanactivetransposonwiththeabilitytotranspose（cfnonautonomouscontrollingelement）.

Autoradiographydetectsradioactivelylabeledmoleculesbytheireffectincreatinganimageonpholtographicfilm.

Autosomesareallthechromosomesexceptthesexchromosomes;adiploidcellhastwocopiesofeachautosome.

Blymphocytes（orBcells）arethecellsresponsibleforsynthesizingantibodies.

Backcrossisanother（earlier）termforatestcross.

Backmutationreversestheeffectofamutationthath