ASCP MOLECULAR BIOLOGY CERTIFICATION EXAM
QUESTIONS WITH CORRECT ANSWERS 2026
How are nucleotides joined together? - CORRECT ANSWER -
Condensation to form phosphodiester bond
Feedback inhibition - CORRECT ANSWER -Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases - CORRECT ANSWER -Degrades nucleic acids by removing one terminal nt at a time
Cleaves phosphodiester bond at end of chain
5' --> 3' and 3' --> 5'
Endonucleases (Prok) - CORRECT ANSWER -Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites - CORRECT ANSWER -nt sequence where replication is initiated
Telomeres - CORRECT ANSWER -
Repeat sequence (TTAGGG) at the ends of chr, protect chr from degradation
Splicesomes - CORRECT ANSWER -Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers - CORRECT ANSWER -
Short regions of DNA that bind proteins (TXN factors) that enhance TXN of a gene
Poly-A tail - CORRECT ANSWER -Prevents mRNA from being degraded in cytoplasm
,100-250 A's at 3' end
5' cap - CORRECT ANSWER -5'-
5' pyrophosphate bridge to a methylated G added to 5' end of a mRNA
Protects against degradation and as a recognition signal for TLN apparatus
Ribosomes - CORRECT ANSWER -Where TLN occurs
Prok: 30s and 50s
Euk: 40s and 60s
Catalyzes peptide bond between a.a.'s
How is translation initiated? - CORRECT ANSWER -
small rRNA (40S) subunit binds mRNA and scans for start codon (AUG)
Met-tRNA is brought to the P site
Large rRNA (60S) subunit binds
How is translation terminated? - CORRECT ANSWER -Occurs when stop codon enters A site
Release factor recognizes stop codon, hydrolyzes ester bond with P site, releasing aa chain
Reversev transcriptasev -v CORRECTv ANSWERv -
enzymev thatv transcribesv RNAv tov cDNAv (lacksv introns)
RNAv -->v RNA:DNAv -->v cDNAv (dsDNA)
Pleiotrophyv -v CORRECTv ANSWERv -
av singlev genev controlsv thev expressionv ofv manyv phenotypicv traits
iev Sicklev Cellv Anemia
cDNAv -v CORRECTv ANSWERv -intronv freev complementaryv DNA
canv bev insertedv intov av plasmid
Vectorv -v CORRECTv ANSWERv -helpsv carryv DNAv intov cell
,v
iev plasmids,v virus
Openv Readingv Framev (ORF)v -v CORRECTv ANSWERv -
sectionsv ofv DNAv thatv beginv withv startv codonsv andv endv withv stopv codon
s
DNA:v 5'v -->v 3'
transcription:v 3'v -->v 5'v DNAv -->v RNAv (promoter)
translation:v 5'v -->v 3'v mRNA
Spectrophotometerv -v CORRECTv ANSWERv -Measuresv amountv ofv lightv absorbed
Quantitativev measurementv ofv [DNA/RNA]
Organicv isolationv methodv -v CORRECTv ANSWERv -1.v Lyse
2.v Addv phenol/v chloroformv >v vortex/spin
3.v Transferv aqueousv layerv (top)v tov newv tube
4.v Addv chloroform:IAAv (removesv phenol)v >v vortex/spin
5.v Transferv aqueousv layerv tov newv tube
6.v Addv NaOAcv andv EtOHv >v vortex/spin
7.v Decant
8.v Resuspend
Howv dov youv inactivatev RNases?v -v CORRECTv ANSWERv -
200Cv forv 2v hrs
3
0v minv inv 1Mv NaOHv orv quanidinumv isothiocyanate
Hybridizationv -v CORRECTv ANSWERv -
2v ssDNAv moleculesv ofv compv basev sequencev canv formv av dsv hybridv (duplex
)
Whatv doesv thev incubationv stepv inv hybridizationv do?v -
v CORRECTv ANSWERv -
Allowsv formationv ofv dsv molecules
Blockingv DNAv (Hybridization)v -v CORRECTv ANSWERv -
minimizesv probev bindingv tov nonspecificv sequence
,v
iev salmonv spermv DNA,v Humanv LINE-1
Blockingv Proteinsv (Hybridization)v -v CORRECTv ANSWERv -
minimizev nonspecificv bindingv ofv probev tov membrane
iev caseinv (milk),v Denhardt'sv sol
Howv canv youv increasev strigencyv inv av hybridization?v -v CORRECTv ANSWERv -
decreasev [salt]
increasev [formamide]
increasev temp
Linev Probev Assayv (LiPA)v -v CORRECTv ANSWERv -
reversev hybridizationv assayv usingv sequence-
specificv oligonucleotidev probesv (reversev SSOP)
multi-parameterv testingv -->v singlev strip
Linev Probev Assayv stepsv -v CORRECTv ANSWERv -
1.v Isolatev nucleicv acidv (RNA)
2.v Amplify
3.v Hybridization
4.v Strigentv wash
5.v Incubatev withv conjugate
6.v Incubatev withv substrate
7.v Detect
Whatv methodv wouldv youv usev ifv youv knewv thev genev sequencev andv thev mutation?
v-
CORRECTv ANSWERv -Reversev Dotv Blot
Microarraysv -v CORRECTv ANSWERv -Usedv forv unknownv genev andv mutation
cDNAv libraries
canv bev usedv forv genev expression,v tumors,v geneticv mapping,v mutationsv andv polymorphis
m
largev scale,v highv throughputv analysis
QUESTIONS WITH CORRECT ANSWERS 2026
How are nucleotides joined together? - CORRECT ANSWER -
Condensation to form phosphodiester bond
Feedback inhibition - CORRECT ANSWER -Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases - CORRECT ANSWER -Degrades nucleic acids by removing one terminal nt at a time
Cleaves phosphodiester bond at end of chain
5' --> 3' and 3' --> 5'
Endonucleases (Prok) - CORRECT ANSWER -Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites - CORRECT ANSWER -nt sequence where replication is initiated
Telomeres - CORRECT ANSWER -
Repeat sequence (TTAGGG) at the ends of chr, protect chr from degradation
Splicesomes - CORRECT ANSWER -Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers - CORRECT ANSWER -
Short regions of DNA that bind proteins (TXN factors) that enhance TXN of a gene
Poly-A tail - CORRECT ANSWER -Prevents mRNA from being degraded in cytoplasm
,100-250 A's at 3' end
5' cap - CORRECT ANSWER -5'-
5' pyrophosphate bridge to a methylated G added to 5' end of a mRNA
Protects against degradation and as a recognition signal for TLN apparatus
Ribosomes - CORRECT ANSWER -Where TLN occurs
Prok: 30s and 50s
Euk: 40s and 60s
Catalyzes peptide bond between a.a.'s
How is translation initiated? - CORRECT ANSWER -
small rRNA (40S) subunit binds mRNA and scans for start codon (AUG)
Met-tRNA is brought to the P site
Large rRNA (60S) subunit binds
How is translation terminated? - CORRECT ANSWER -Occurs when stop codon enters A site
Release factor recognizes stop codon, hydrolyzes ester bond with P site, releasing aa chain
Reversev transcriptasev -v CORRECTv ANSWERv -
enzymev thatv transcribesv RNAv tov cDNAv (lacksv introns)
RNAv -->v RNA:DNAv -->v cDNAv (dsDNA)
Pleiotrophyv -v CORRECTv ANSWERv -
av singlev genev controlsv thev expressionv ofv manyv phenotypicv traits
iev Sicklev Cellv Anemia
cDNAv -v CORRECTv ANSWERv -intronv freev complementaryv DNA
canv bev insertedv intov av plasmid
Vectorv -v CORRECTv ANSWERv -helpsv carryv DNAv intov cell
,v
iev plasmids,v virus
Openv Readingv Framev (ORF)v -v CORRECTv ANSWERv -
sectionsv ofv DNAv thatv beginv withv startv codonsv andv endv withv stopv codon
s
DNA:v 5'v -->v 3'
transcription:v 3'v -->v 5'v DNAv -->v RNAv (promoter)
translation:v 5'v -->v 3'v mRNA
Spectrophotometerv -v CORRECTv ANSWERv -Measuresv amountv ofv lightv absorbed
Quantitativev measurementv ofv [DNA/RNA]
Organicv isolationv methodv -v CORRECTv ANSWERv -1.v Lyse
2.v Addv phenol/v chloroformv >v vortex/spin
3.v Transferv aqueousv layerv (top)v tov newv tube
4.v Addv chloroform:IAAv (removesv phenol)v >v vortex/spin
5.v Transferv aqueousv layerv tov newv tube
6.v Addv NaOAcv andv EtOHv >v vortex/spin
7.v Decant
8.v Resuspend
Howv dov youv inactivatev RNases?v -v CORRECTv ANSWERv -
200Cv forv 2v hrs
3
0v minv inv 1Mv NaOHv orv quanidinumv isothiocyanate
Hybridizationv -v CORRECTv ANSWERv -
2v ssDNAv moleculesv ofv compv basev sequencev canv formv av dsv hybridv (duplex
)
Whatv doesv thev incubationv stepv inv hybridizationv do?v -
v CORRECTv ANSWERv -
Allowsv formationv ofv dsv molecules
Blockingv DNAv (Hybridization)v -v CORRECTv ANSWERv -
minimizesv probev bindingv tov nonspecificv sequence
,v
iev salmonv spermv DNA,v Humanv LINE-1
Blockingv Proteinsv (Hybridization)v -v CORRECTv ANSWERv -
minimizev nonspecificv bindingv ofv probev tov membrane
iev caseinv (milk),v Denhardt'sv sol
Howv canv youv increasev strigencyv inv av hybridization?v -v CORRECTv ANSWERv -
decreasev [salt]
increasev [formamide]
increasev temp
Linev Probev Assayv (LiPA)v -v CORRECTv ANSWERv -
reversev hybridizationv assayv usingv sequence-
specificv oligonucleotidev probesv (reversev SSOP)
multi-parameterv testingv -->v singlev strip
Linev Probev Assayv stepsv -v CORRECTv ANSWERv -
1.v Isolatev nucleicv acidv (RNA)
2.v Amplify
3.v Hybridization
4.v Strigentv wash
5.v Incubatev withv conjugate
6.v Incubatev withv substrate
7.v Detect
Whatv methodv wouldv youv usev ifv youv knewv thev genev sequencev andv thev mutation?
v-
CORRECTv ANSWERv -Reversev Dotv Blot
Microarraysv -v CORRECTv ANSWERv -Usedv forv unknownv genev andv mutation
cDNAv libraries
canv bev usedv forv genev expression,v tumors,v geneticv mapping,v mutationsv andv polymorphis
m
largev scale,v highv throughputv analysis
