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
Reversex transcriptasex -x CORRECTx ANSWERx -
enzymex thatx transcribesx RNAx tox cDNAx (lacksx introns)
RNAx -->x RNA:DNAx -->x cDNAx (dsDNA)
Pleiotrophyx -x CORRECTx ANSWERx -
ax singlex genex controlsx thex expressionx ofx manyx phenotypicx traits
iex Sicklex Cellx Anemia
cDNAx -x CORRECTx ANSWERx -intronx freex complementaryx DNA
canx bex insertedx intox ax plasmid
Vectorx -x CORRECTx ANSWERx -helpsx carryx DNAx intox cell
,x
iex plasmids,x virus
Openx Readingx Framex (ORF)x -x CORRECTx ANSWERx -
sectionsx ofx DNAx thatx beginx withx startx codonsx andx endx withx stopx codon
s
DNA:x 5'x -->x 3'
transcription:x 3'x -->x 5'x DNAx -->x RNAx (promoter)
translation:x 5'x -->x 3'x mRNA
Spectrophotometerx -x CORRECTx ANSWERx -Measuresx amountx ofx lightx absorbed
Quantitativex measurementx ofx [DNA/RNA]
Organicx isolationx methodx -x CORRECTx ANSWERx -1.x Lyse
2.x Addx phenol/x chloroformx >x vortex/spin
3.x Transferx aqueousx layerx (top)x tox newx tube
4.x Addx chloroform:IAAx (removesx phenol)x >x vortex/spin
5.x Transferx aqueousx layerx tox newx tube
6.x Addx NaOAcx andx EtOHx >x vortex/spin
7.x Decant
8.x Resuspend
Howx dox youx inactivatex RNases?x -x CORRECTx ANSWERx -
200Cx forx 2x hrs
3
0x minx inx 1Mx NaOHx orx quanidinumx isothiocyanate
Hybridizationx -x CORRECTx ANSWERx -
2x ssDNAx moleculesx ofx compx basex sequencex canx formx ax dsx hybridx (duplex
)
Whatx doesx thex incubationx stepx inx hybridizationx do?x -
x CORRECTx ANSWERx -
Allowsx formationx ofx dsx molecules
Blockingx DNAx (Hybridization)x -x CORRECTx ANSWERx -
minimizesx probex bindingx tox nonspecificx sequence
,x
iex salmonx spermx DNA,x Humanx LINE-1
Blockingx Proteinsx (Hybridization)x -x CORRECTx ANSWERx -
minimizex nonspecificx bindingx ofx probex tox membrane
iex caseinx (milk),x Denhardt'sx sol
Howx canx youx increasex strigencyx inx ax hybridization?x -x CORRECTx ANSWERx -
decreasex [salt]
increasex [formamide]
increasex temp
Linex Probex Assayx (LiPA)x -x CORRECTx ANSWERx -
reversex hybridizationx assayx usingx sequence-
specificx oligonucleotidex probesx (reversex SSOP)
multi-parameterx testingx -->x singlex strip
Linex Probex Assayx stepsx -x CORRECTx ANSWERx -
1.x Isolatex nucleicx acidx (RNA)
2.x Amplify
3.x Hybridization
4.x Strigentx wash
5.x Incubatex withx conjugate
6.x Incubatex withx substrate
7.x Detect
Whatx methodx wouldx youx usex ifx youx knewx thex genex sequencex andx thex mutation?
x-
CORRECTx ANSWERx -Reversex Dotx Blot
Microarraysx -x CORRECTx ANSWERx -Usedx forx unknownx genex andx mutation
cDNAx libraries
canx bex usedx forx genex expression,x tumors,x geneticx mapping,x mutationsx andx polymorphis
m
largex scale,x highx throughputx 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
Reversex transcriptasex -x CORRECTx ANSWERx -
enzymex thatx transcribesx RNAx tox cDNAx (lacksx introns)
RNAx -->x RNA:DNAx -->x cDNAx (dsDNA)
Pleiotrophyx -x CORRECTx ANSWERx -
ax singlex genex controlsx thex expressionx ofx manyx phenotypicx traits
iex Sicklex Cellx Anemia
cDNAx -x CORRECTx ANSWERx -intronx freex complementaryx DNA
canx bex insertedx intox ax plasmid
Vectorx -x CORRECTx ANSWERx -helpsx carryx DNAx intox cell
,x
iex plasmids,x virus
Openx Readingx Framex (ORF)x -x CORRECTx ANSWERx -
sectionsx ofx DNAx thatx beginx withx startx codonsx andx endx withx stopx codon
s
DNA:x 5'x -->x 3'
transcription:x 3'x -->x 5'x DNAx -->x RNAx (promoter)
translation:x 5'x -->x 3'x mRNA
Spectrophotometerx -x CORRECTx ANSWERx -Measuresx amountx ofx lightx absorbed
Quantitativex measurementx ofx [DNA/RNA]
Organicx isolationx methodx -x CORRECTx ANSWERx -1.x Lyse
2.x Addx phenol/x chloroformx >x vortex/spin
3.x Transferx aqueousx layerx (top)x tox newx tube
4.x Addx chloroform:IAAx (removesx phenol)x >x vortex/spin
5.x Transferx aqueousx layerx tox newx tube
6.x Addx NaOAcx andx EtOHx >x vortex/spin
7.x Decant
8.x Resuspend
Howx dox youx inactivatex RNases?x -x CORRECTx ANSWERx -
200Cx forx 2x hrs
3
0x minx inx 1Mx NaOHx orx quanidinumx isothiocyanate
Hybridizationx -x CORRECTx ANSWERx -
2x ssDNAx moleculesx ofx compx basex sequencex canx formx ax dsx hybridx (duplex
)
Whatx doesx thex incubationx stepx inx hybridizationx do?x -
x CORRECTx ANSWERx -
Allowsx formationx ofx dsx molecules
Blockingx DNAx (Hybridization)x -x CORRECTx ANSWERx -
minimizesx probex bindingx tox nonspecificx sequence
,x
iex salmonx spermx DNA,x Humanx LINE-1
Blockingx Proteinsx (Hybridization)x -x CORRECTx ANSWERx -
minimizex nonspecificx bindingx ofx probex tox membrane
iex caseinx (milk),x Denhardt'sx sol
Howx canx youx increasex strigencyx inx ax hybridization?x -x CORRECTx ANSWERx -
decreasex [salt]
increasex [formamide]
increasex temp
Linex Probex Assayx (LiPA)x -x CORRECTx ANSWERx -
reversex hybridizationx assayx usingx sequence-
specificx oligonucleotidex probesx (reversex SSOP)
multi-parameterx testingx -->x singlex strip
Linex Probex Assayx stepsx -x CORRECTx ANSWERx -
1.x Isolatex nucleicx acidx (RNA)
2.x Amplify
3.x Hybridization
4.x Strigentx wash
5.x Incubatex withx conjugate
6.x Incubatex withx substrate
7.x Detect
Whatx methodx wouldx youx usex ifx youx knewx thex genex sequencex andx thex mutation?
x-
CORRECTx ANSWERx -Reversex Dotx Blot
Microarraysx -x CORRECTx ANSWERx -Usedx forx unknownx genex andx mutation
cDNAx libraries
canx bex usedx forx genex expression,x tumors,x geneticx mapping,x mutationsx andx polymorphis
m
largex scale,x highx throughputx analysis
