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
Reversez transcriptasez -z CORRECTz ANSWERz -enzymez thatz transcribesz RNAz toz cDNAz (lacksz introns)
RNAz -->z RNA:DNAz -->z cDNAz (dsDNA)
Pleiotrophyz -z CORRECTz ANSWERz -az singlez genez controlsz thez expressionz ofz manyz phenotypicz traits
iez Sicklez Cellz Anemia
cDNAz -z CORRECTz ANSWERz -intronz freez complementaryz DNA
canz bez insertedz intoz az plasmid
Vectorz -z CORRECTz ANSWERz -helpsz carryz DNAz intoz cell
,z
iez plasmids,z virus
Openz Readingz Framez (ORF)z -z CORRECTz ANSWERz -
sectionsz ofz DNAz thatz beginz withz startz codonsz andz endz withz stopz codons
DNA:z 5'z -->z 3'
transcription:z 3'z -->z 5'z DNAz -->z RNAz (promoter)
translation:z 5'z -->z 3'z mRNA
Spectrophotometerz -z CORRECTz ANSWERz -Measuresz amountz ofz lightz absorbed
Quantitativez measurementz ofz [DNA/RNA]
Organicz isolationz methodz -z CORRECTz ANSWERz -1.z Lyse
2.z Addz phenol/z chloroformz >z vortex/spin
3.z Transferz aqueousz layerz (top)z toz newz tube
4.z Addz chloroform:IAAz (removesz phenol)z >z vortex/spin
5.z Transferz aqueousz layerz toz newz tube
6.z Addz NaOAcz andz EtOHz >z vortex/spin
7.z Decant
8.z Resuspend
Howz doz youz inactivatez RNases?z -z CORRECTz ANSWERz -200Cz forz 2z hrs
30z minz inz 1Mz NaOHz orz quanidinumz isothiocyanate
Hybridizationz -z CORRECTz ANSWERz -
2z ssDNAz moleculesz ofz compz basez sequencez canz formz az dsz hybridz (duplex)
Whatz doesz thez incubationz stepz inz hybridizationz do?z -z CORRECTz ANSWERz -
Allowsz formationz ofz dsz molecules
Blockingz DNAz (Hybridization)z -z CORRECTz ANSWERz -minimizesz probez bindingz toz nonspecificz sequence
,z
iez salmonz spermz DNA,z Humanz LINE-1
Blockingz Proteinsz (Hybridization)z -z CORRECTz ANSWERz -
minimizez nonspecificz bindingz ofz probez toz membrane
iez caseinz (milk),z Denhardt'sz sol
Howz canz youz increasez strigencyz inz az hybridization?z -z CORRECTz ANSWERz -decreasez [salt]
increasez [formamide]
increasez temp
Linez Probez Assayz (LiPA)z -z CORRECTz ANSWERz -reversez hybridizationz assayz usingz sequence-
specificz oligonucleotidez probesz (reversez SSOP)
multi-parameterz testingz -->z singlez strip
Linez Probez Assayz stepsz -z CORRECTz ANSWERz -1.z Isolatez nucleicz acidz (RNA)
2.z Amplify
3.z Hybridization
4.z Strigentz wash
5.z Incubatez withz conjugate
6.z Incubatez withz substrate
7.z Detect
Whatz methodz wouldz youz usez ifz youz knewz thez genez sequencez andz thez mutation?z -
CORRECTz ANSWERz -Reversez Dotz Blot
Microarraysz -z CORRECTz ANSWERz -Usedz forz unknownz genez andz mutation
cDNAz libraries
canz bez usedz forz genez expression,z tumors,z geneticz mapping,z mutationsz andz polymorphism
largez scale,z highz throughputz 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
Reversez transcriptasez -z CORRECTz ANSWERz -enzymez thatz transcribesz RNAz toz cDNAz (lacksz introns)
RNAz -->z RNA:DNAz -->z cDNAz (dsDNA)
Pleiotrophyz -z CORRECTz ANSWERz -az singlez genez controlsz thez expressionz ofz manyz phenotypicz traits
iez Sicklez Cellz Anemia
cDNAz -z CORRECTz ANSWERz -intronz freez complementaryz DNA
canz bez insertedz intoz az plasmid
Vectorz -z CORRECTz ANSWERz -helpsz carryz DNAz intoz cell
,z
iez plasmids,z virus
Openz Readingz Framez (ORF)z -z CORRECTz ANSWERz -
sectionsz ofz DNAz thatz beginz withz startz codonsz andz endz withz stopz codons
DNA:z 5'z -->z 3'
transcription:z 3'z -->z 5'z DNAz -->z RNAz (promoter)
translation:z 5'z -->z 3'z mRNA
Spectrophotometerz -z CORRECTz ANSWERz -Measuresz amountz ofz lightz absorbed
Quantitativez measurementz ofz [DNA/RNA]
Organicz isolationz methodz -z CORRECTz ANSWERz -1.z Lyse
2.z Addz phenol/z chloroformz >z vortex/spin
3.z Transferz aqueousz layerz (top)z toz newz tube
4.z Addz chloroform:IAAz (removesz phenol)z >z vortex/spin
5.z Transferz aqueousz layerz toz newz tube
6.z Addz NaOAcz andz EtOHz >z vortex/spin
7.z Decant
8.z Resuspend
Howz doz youz inactivatez RNases?z -z CORRECTz ANSWERz -200Cz forz 2z hrs
30z minz inz 1Mz NaOHz orz quanidinumz isothiocyanate
Hybridizationz -z CORRECTz ANSWERz -
2z ssDNAz moleculesz ofz compz basez sequencez canz formz az dsz hybridz (duplex)
Whatz doesz thez incubationz stepz inz hybridizationz do?z -z CORRECTz ANSWERz -
Allowsz formationz ofz dsz molecules
Blockingz DNAz (Hybridization)z -z CORRECTz ANSWERz -minimizesz probez bindingz toz nonspecificz sequence
,z
iez salmonz spermz DNA,z Humanz LINE-1
Blockingz Proteinsz (Hybridization)z -z CORRECTz ANSWERz -
minimizez nonspecificz bindingz ofz probez toz membrane
iez caseinz (milk),z Denhardt'sz sol
Howz canz youz increasez strigencyz inz az hybridization?z -z CORRECTz ANSWERz -decreasez [salt]
increasez [formamide]
increasez temp
Linez Probez Assayz (LiPA)z -z CORRECTz ANSWERz -reversez hybridizationz assayz usingz sequence-
specificz oligonucleotidez probesz (reversez SSOP)
multi-parameterz testingz -->z singlez strip
Linez Probez Assayz stepsz -z CORRECTz ANSWERz -1.z Isolatez nucleicz acidz (RNA)
2.z Amplify
3.z Hybridization
4.z Strigentz wash
5.z Incubatez withz conjugate
6.z Incubatez withz substrate
7.z Detect
Whatz methodz wouldz youz usez ifz youz knewz thez genez sequencez andz thez mutation?z -
CORRECTz ANSWERz -Reversez Dotz Blot
Microarraysz -z CORRECTz ANSWERz -Usedz forz unknownz genez andz mutation
cDNAz libraries
canz bez usedz forz genez expression,z tumors,z geneticz mapping,z mutationsz andz polymorphism
largez scale,z highz throughputz analysis
