ASCP Molecular Biology Certification
Exam Questions and Answers
Updated 2026
PyrimidineM-MAnswerMOneMcarbonMring
Cytosine,MThymine,MUracil
PurineM-MAnswerMTwoMcarbonMrings
Adenine,MGuanine
HowMareMnucleotidesMjoinedMtogether?M-
MAnswerMCondensationMtoMformMphosphodiesterMbond
WhatMisMtheMfunctionMofMmRNA?M-MAnswerMCarriesMgeneticMinfoMoutMofMnucleus
TranscriptMtranslatedMtoMprotein
WhatMisMtheMfunctionMofMtRNA?M-MAnswerMCarriesMaaMtoMribosome
AnticodonMpairsMwithMcodonMonMmRNAMstrand
WhatMisMtheMfunctionMofMrRNA?M-MAnswerMpartMofMribosomeMstructure
mostMabundantMRNA
coordinatedMcouplingMofMtRNAMtoMmRNAMcodons
FeedbackMinhibitionM-MAnswerMProductMofMpathwayMisMnoncompetitiveMinhibitor
BindsMtoMallostericMsiteMtoMslowMdownMrxnMb/cMtooMmuchMproduct
ExonucleasesM-
MAnswerMDegradesMnucleicMacidsMbyMremovingMoneMterminalMntMatMaMtime
CleavesMphosphodiesterMbondMatMendMofMchain
5'M-->M3'MandM3'M-->M5'
EndonucleasesM(Prok)M-MAnswerMRestrictionMenzymes
,CleavesMphoshpodiesterMbondsMw/iMpoly-ntMchain
RecognitionMsiteMisMpalindromicMsequence
TypesMI-V
ORIMsitesM-MAnswerMntMsequenceMwhereMreplicationMisMinitiated
TopoisomeraseMIM-MAnswerMInducesMssMbreaks
RemoveMDNAMsupercoilsMduringMTXNMandMDNAMreplication;MforMstrandMbreakageMdurin
gMrecombination;MforMchrMcondensation;MandMtoMdisentangleMintertwinedMDNAMduringM
mitosis
topoisomeraseMIIM-
MAnswerMcutsMbothMstrandsMofMoneMDNAMdoubleMhelix,MpassesManotherMunbrokenMD
NAMhelixMthroughMit,MandMthenMreannealsMtheMcutMstrands
GyraseM(topoisomeraseMII)M-
MAnswerMUnwindsMsupercoilingMcausedMbyMunwindingMatMtheMrepMforkMbyMintroducing
MDSBs
HelicaseM-MAnswerMBreaksMH-bondsMofMdoubleMhelixMatMtheMreplicationMfork
PrimaseM-MAnswerMDNApolMαM(DNAMdepMRNAMpol)
addsMshortMsegmentsMofMcomplementaryM
RNAMtoMssDNAMtemplateM(primers),MservesMasMstartingMpointsMforMreplication
single-strandMDNAMbindingMproteinsM(SSBPs)M-
MAnswerMBindsMssDNAMandMpreventsMitMfromMre-
annealingMduringMTXN,Mreplication,Mrepair,MandMrecombination
OkazakiMfragmentsM-
MAnswerMShortMfragmentsMofMDNAMsynthesizedMbyMDNApolMδMusingMtheMlaggingMstra
ndM(3'->5')MasMaMtemplate
LigaseM-MAnswerMClosesMgapsMinMDNAM
,CatalyzesMphosphodiesterMbondMbetweenM3'OHMandM5'P
WhatMareMtheMstepsMinMDNAMreplication?M-MAnswerM1.MInitiate
2.MElongate
3.MTerminate
TelomeresM-
MAnswerMRepeatMsequenceM(TTAGGG)MatMtheMendsMofMchr,MprotectMchrMfromMdegrad
ation
RNAMpolymeraseM-MAnswerMDNAMdependentMRNApol
TranscribesMDNAMtemplateMtoMRNAM(3'-->5';Manti-parallel)
SplicesomesM-MAnswerMComplexMofMsnRNPs
RemovesMintronsMfromMpre-mRNAMandMsplicesMexonsMtogether
EnhancersM-
MAnswerMShortMregionsMofMDNAMthatMbindMproteinsM(TXNMfactors)MthatMenhanceMTXN
MofMaMgene
Poly-AMtailM-MAnswerMPreventsMmRNAMfromMbeingMdegradedMinMcytoplasm
100-250MA'sMatM3'Mend
5'McapM-MAnswerM5'-
5'MpyrophosphateMbridgeMtoMaMmethylatedMGMaddedMtoM5'MendMofMaMmRNA
ProtectsMagainstMdegradationMandMasMaMrecognitionMsignalMforMTLNMapparatus
aminoacylMtRNAM-MAnswerMtRNAsMthatMcarryMaminoMacids
RibosomesM-MAnswerMWhereMTLNMoccurs
Prok:M30sMandM50s
Euk:M40sMandM60s
CatalyzesMpeptideMbondMbetweenMa.a.'s
, WhatMisMtheMpathMofMaMtRNAMinMaMribosome?M-
MAnswerMAcceptorM>MPeptidylM>MExit
HowMisMtranslationMinitiated?M-
MAnswerMsmallMrRNAM(40S)MsubunitMbindsMmRNAMandMscansMforMstartMcodonM(AUG)
Met-tRNAMisMbroughtMtoMtheMPMsite
LargeMrRNAM(60S)MsubunitMbinds
HowMisMtranslationMterminated?M-MAnswerMOccursMwhenMstopMcodonMentersMAMsite
ReleaseMfactorMrecognizesMstopMcodon,MhydrolyzesMesterMbondMwithMPMsite,MreleasingM
aaMchain
ReverseMtranscriptaseM-MAnswerMenzymeMthatMtranscribesMRNAMtoMcDNAM(lacksMintrons)
RNAM-->MRNA:DNAM-->McDNAM(dsDNA)
PleiotrophyM-
MAnswerMaMsingleMgeneMcontrolsMtheMexpressionMofMmanyMphenotypicMtraits
ieMSickleMCellMAnemia
cDNAM-MAnswerMintronMfreeMcomplementaryMDNAM
canMbeMinsertedMintoMaMplasmid
VectorM-MAnswerMhelpsMcarryMDNAMintoMcellM
ieMplasmids,Mvirus
OpenMReadingMFrameM(ORF)M-
MAnswerMsectionsMofMDNAMthatMbeginMwithMstartMcodonsMandMendMwithMstopMcodon
s
DNA:M5'M-->M3'
transcription:M3'M-->M5'MDNAM-->MRNAM(promoter)
translation:M5'M-->M3'MmRNA
Exam Questions and Answers
Updated 2026
PyrimidineM-MAnswerMOneMcarbonMring
Cytosine,MThymine,MUracil
PurineM-MAnswerMTwoMcarbonMrings
Adenine,MGuanine
HowMareMnucleotidesMjoinedMtogether?M-
MAnswerMCondensationMtoMformMphosphodiesterMbond
WhatMisMtheMfunctionMofMmRNA?M-MAnswerMCarriesMgeneticMinfoMoutMofMnucleus
TranscriptMtranslatedMtoMprotein
WhatMisMtheMfunctionMofMtRNA?M-MAnswerMCarriesMaaMtoMribosome
AnticodonMpairsMwithMcodonMonMmRNAMstrand
WhatMisMtheMfunctionMofMrRNA?M-MAnswerMpartMofMribosomeMstructure
mostMabundantMRNA
coordinatedMcouplingMofMtRNAMtoMmRNAMcodons
FeedbackMinhibitionM-MAnswerMProductMofMpathwayMisMnoncompetitiveMinhibitor
BindsMtoMallostericMsiteMtoMslowMdownMrxnMb/cMtooMmuchMproduct
ExonucleasesM-
MAnswerMDegradesMnucleicMacidsMbyMremovingMoneMterminalMntMatMaMtime
CleavesMphosphodiesterMbondMatMendMofMchain
5'M-->M3'MandM3'M-->M5'
EndonucleasesM(Prok)M-MAnswerMRestrictionMenzymes
,CleavesMphoshpodiesterMbondsMw/iMpoly-ntMchain
RecognitionMsiteMisMpalindromicMsequence
TypesMI-V
ORIMsitesM-MAnswerMntMsequenceMwhereMreplicationMisMinitiated
TopoisomeraseMIM-MAnswerMInducesMssMbreaks
RemoveMDNAMsupercoilsMduringMTXNMandMDNAMreplication;MforMstrandMbreakageMdurin
gMrecombination;MforMchrMcondensation;MandMtoMdisentangleMintertwinedMDNAMduringM
mitosis
topoisomeraseMIIM-
MAnswerMcutsMbothMstrandsMofMoneMDNAMdoubleMhelix,MpassesManotherMunbrokenMD
NAMhelixMthroughMit,MandMthenMreannealsMtheMcutMstrands
GyraseM(topoisomeraseMII)M-
MAnswerMUnwindsMsupercoilingMcausedMbyMunwindingMatMtheMrepMforkMbyMintroducing
MDSBs
HelicaseM-MAnswerMBreaksMH-bondsMofMdoubleMhelixMatMtheMreplicationMfork
PrimaseM-MAnswerMDNApolMαM(DNAMdepMRNAMpol)
addsMshortMsegmentsMofMcomplementaryM
RNAMtoMssDNAMtemplateM(primers),MservesMasMstartingMpointsMforMreplication
single-strandMDNAMbindingMproteinsM(SSBPs)M-
MAnswerMBindsMssDNAMandMpreventsMitMfromMre-
annealingMduringMTXN,Mreplication,Mrepair,MandMrecombination
OkazakiMfragmentsM-
MAnswerMShortMfragmentsMofMDNAMsynthesizedMbyMDNApolMδMusingMtheMlaggingMstra
ndM(3'->5')MasMaMtemplate
LigaseM-MAnswerMClosesMgapsMinMDNAM
,CatalyzesMphosphodiesterMbondMbetweenM3'OHMandM5'P
WhatMareMtheMstepsMinMDNAMreplication?M-MAnswerM1.MInitiate
2.MElongate
3.MTerminate
TelomeresM-
MAnswerMRepeatMsequenceM(TTAGGG)MatMtheMendsMofMchr,MprotectMchrMfromMdegrad
ation
RNAMpolymeraseM-MAnswerMDNAMdependentMRNApol
TranscribesMDNAMtemplateMtoMRNAM(3'-->5';Manti-parallel)
SplicesomesM-MAnswerMComplexMofMsnRNPs
RemovesMintronsMfromMpre-mRNAMandMsplicesMexonsMtogether
EnhancersM-
MAnswerMShortMregionsMofMDNAMthatMbindMproteinsM(TXNMfactors)MthatMenhanceMTXN
MofMaMgene
Poly-AMtailM-MAnswerMPreventsMmRNAMfromMbeingMdegradedMinMcytoplasm
100-250MA'sMatM3'Mend
5'McapM-MAnswerM5'-
5'MpyrophosphateMbridgeMtoMaMmethylatedMGMaddedMtoM5'MendMofMaMmRNA
ProtectsMagainstMdegradationMandMasMaMrecognitionMsignalMforMTLNMapparatus
aminoacylMtRNAM-MAnswerMtRNAsMthatMcarryMaminoMacids
RibosomesM-MAnswerMWhereMTLNMoccurs
Prok:M30sMandM50s
Euk:M40sMandM60s
CatalyzesMpeptideMbondMbetweenMa.a.'s
, WhatMisMtheMpathMofMaMtRNAMinMaMribosome?M-
MAnswerMAcceptorM>MPeptidylM>MExit
HowMisMtranslationMinitiated?M-
MAnswerMsmallMrRNAM(40S)MsubunitMbindsMmRNAMandMscansMforMstartMcodonM(AUG)
Met-tRNAMisMbroughtMtoMtheMPMsite
LargeMrRNAM(60S)MsubunitMbinds
HowMisMtranslationMterminated?M-MAnswerMOccursMwhenMstopMcodonMentersMAMsite
ReleaseMfactorMrecognizesMstopMcodon,MhydrolyzesMesterMbondMwithMPMsite,MreleasingM
aaMchain
ReverseMtranscriptaseM-MAnswerMenzymeMthatMtranscribesMRNAMtoMcDNAM(lacksMintrons)
RNAM-->MRNA:DNAM-->McDNAM(dsDNA)
PleiotrophyM-
MAnswerMaMsingleMgeneMcontrolsMtheMexpressionMofMmanyMphenotypicMtraits
ieMSickleMCellMAnemia
cDNAM-MAnswerMintronMfreeMcomplementaryMDNAM
canMbeMinsertedMintoMaMplasmid
VectorM-MAnswerMhelpsMcarryMDNAMintoMcellM
ieMplasmids,Mvirus
OpenMReadingMFrameM(ORF)M-
MAnswerMsectionsMofMDNAMthatMbeginMwithMstartMcodonsMandMendMwithMstopMcodon
s
DNA:M5'M-->M3'
transcription:M3'M-->M5'MDNAM-->MRNAM(promoter)
translation:M5'M-->M3'MmRNA
