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
Reversec transcriptasec -c CORRECTc ANSWERc -enzymec thatc transcribesc RNAc toc cDNAc (lacksc introns)
RNAc -->c RNA:DNAc -->c cDNAc (dsDNA)
Pleiotrophyc -c CORRECTc ANSWERc -ac singlec genec controlsc thec expressionc ofc manyc phenotypicc traits
iec Sicklec Cellc Anemia
cDNAc -c CORRECTc ANSWERc -intronc freec complementaryc DNA
canc bec insertedc intoc ac plasmid
Vectorc -c CORRECTc ANSWERc -helpsc carryc DNAc intoc cell
,c
iec plasmids,c virus
Openc Readingc Framec (ORF)c -c CORRECTc ANSWERc -
sectionsc ofc DNAc thatc beginc withc startc codonsc andc endc withc stopc codons
DNA:c 5'c -->c 3'
transcription:c 3'c -->c 5'c DNAc -->c RNAc (promoter)
translation:c 5'c -->c 3'c mRNA
Spectrophotometerc -c CORRECTc ANSWERc -Measuresc amountc ofc lightc absorbed
Quantitativec measurementc ofc [DNA/RNA]
Organicc isolationc methodc -c CORRECTc ANSWERc -1.c Lyse
2.c Addc phenol/c chloroformc >c vortex/spin
3.c Transferc aqueousc layerc (top)c toc newc tube
4.c Addc chloroform:IAAc (removesc phenol)c >c vortex/spin
5.c Transferc aqueousc layerc toc newc tube
6.c Addc NaOAcc andc EtOHc >c vortex/spin
7.c Decant
8.c Resuspend
Howc doc youc inactivatec RNases?c -c CORRECTc ANSWERc -200Cc forc 2c hrs
30c minc inc 1Mc NaOHc orc quanidinumc isothiocyanate
Hybridizationc -c CORRECTc ANSWERc -
2c ssDNAc moleculesc ofc compc basec sequencec canc formc ac dsc hybridc (duplex)
Whatc doesc thec incubationc stepc inc hybridizationc do?c -c CORRECTc ANSWERc -
Allowsc formationc ofc dsc molecules
Blockingc DNAc (Hybridization)c -c CORRECTc ANSWERc -minimizesc probec bindingc toc nonspecificc sequence
,c
iec salmonc spermc DNA,c Humanc LINE-1
Blockingc Proteinsc (Hybridization)c -c CORRECTc ANSWERc -
minimizec nonspecificc bindingc ofc probec toc membrane
iec caseinc (milk),c Denhardt'sc sol
Howc canc youc increasec strigencyc inc ac hybridization?c -c CORRECTc ANSWERc -decreasec [salt]
increasec [formamide]
increasec temp
Linec Probec Assayc (LiPA)c -c CORRECTc ANSWERc -reversec hybridizationc assayc usingc sequence-
specificc oligonucleotidec probesc (reversec SSOP)
multi-parameterc testingc -->c singlec strip
Linec Probec Assayc stepsc -c CORRECTc ANSWERc -1.c Isolatec nucleicc acidc (RNA)
2.c Amplify
3.c Hybridization
4.c Strigentc wash
5.c Incubatec withc conjugate
6.c Incubatec withc substrate
7.c Detect
Whatc methodc wouldc youc usec ifc youc knewc thec genec sequencec andc thec mutation?c -
CORRECTc ANSWERc -Reversec Dotc Blot
Microarraysc -c CORRECTc ANSWERc -Usedc forc unknownc genec andc mutation
cDNAc libraries
canc bec usedc forc genec expression,c tumors,c geneticc mapping,c mutationsc andc polymorphism
largec scale,c highc throughputc 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
Reversec transcriptasec -c CORRECTc ANSWERc -enzymec thatc transcribesc RNAc toc cDNAc (lacksc introns)
RNAc -->c RNA:DNAc -->c cDNAc (dsDNA)
Pleiotrophyc -c CORRECTc ANSWERc -ac singlec genec controlsc thec expressionc ofc manyc phenotypicc traits
iec Sicklec Cellc Anemia
cDNAc -c CORRECTc ANSWERc -intronc freec complementaryc DNA
canc bec insertedc intoc ac plasmid
Vectorc -c CORRECTc ANSWERc -helpsc carryc DNAc intoc cell
,c
iec plasmids,c virus
Openc Readingc Framec (ORF)c -c CORRECTc ANSWERc -
sectionsc ofc DNAc thatc beginc withc startc codonsc andc endc withc stopc codons
DNA:c 5'c -->c 3'
transcription:c 3'c -->c 5'c DNAc -->c RNAc (promoter)
translation:c 5'c -->c 3'c mRNA
Spectrophotometerc -c CORRECTc ANSWERc -Measuresc amountc ofc lightc absorbed
Quantitativec measurementc ofc [DNA/RNA]
Organicc isolationc methodc -c CORRECTc ANSWERc -1.c Lyse
2.c Addc phenol/c chloroformc >c vortex/spin
3.c Transferc aqueousc layerc (top)c toc newc tube
4.c Addc chloroform:IAAc (removesc phenol)c >c vortex/spin
5.c Transferc aqueousc layerc toc newc tube
6.c Addc NaOAcc andc EtOHc >c vortex/spin
7.c Decant
8.c Resuspend
Howc doc youc inactivatec RNases?c -c CORRECTc ANSWERc -200Cc forc 2c hrs
30c minc inc 1Mc NaOHc orc quanidinumc isothiocyanate
Hybridizationc -c CORRECTc ANSWERc -
2c ssDNAc moleculesc ofc compc basec sequencec canc formc ac dsc hybridc (duplex)
Whatc doesc thec incubationc stepc inc hybridizationc do?c -c CORRECTc ANSWERc -
Allowsc formationc ofc dsc molecules
Blockingc DNAc (Hybridization)c -c CORRECTc ANSWERc -minimizesc probec bindingc toc nonspecificc sequence
,c
iec salmonc spermc DNA,c Humanc LINE-1
Blockingc Proteinsc (Hybridization)c -c CORRECTc ANSWERc -
minimizec nonspecificc bindingc ofc probec toc membrane
iec caseinc (milk),c Denhardt'sc sol
Howc canc youc increasec strigencyc inc ac hybridization?c -c CORRECTc ANSWERc -decreasec [salt]
increasec [formamide]
increasec temp
Linec Probec Assayc (LiPA)c -c CORRECTc ANSWERc -reversec hybridizationc assayc usingc sequence-
specificc oligonucleotidec probesc (reversec SSOP)
multi-parameterc testingc -->c singlec strip
Linec Probec Assayc stepsc -c CORRECTc ANSWERc -1.c Isolatec nucleicc acidc (RNA)
2.c Amplify
3.c Hybridization
4.c Strigentc wash
5.c Incubatec withc conjugate
6.c Incubatec withc substrate
7.c Detect
Whatc methodc wouldc youc usec ifc youc knewc thec genec sequencec andc thec mutation?c -
CORRECTc ANSWERc -Reversec Dotc Blot
Microarraysc -c CORRECTc ANSWERc -Usedc forc unknownc genec andc mutation
cDNAc libraries
canc bec usedc forc genec expression,c tumors,c geneticc mapping,c mutationsc andc polymorphism
largec scale,c highc throughputc analysis
