ASCP Molecular Biology
Certification Exam Questions and
Answers 100% PASS
Pyrimidine—ANSWER-One carbon ring
Cytosine, Thymine, Uracil
Purine—ANSWER-Two carbon rings
Adenine, Guanine
How are nucleotides joined together?—ANSWER-Condensation to form phosphodiester
bond
What is the function of mRNA?—ANSWER-Carries genetic info out of nucleus
Transcript translated to protein
What is the function of tRNA?—ANSWER-Carries aa to ribosome
Anticodon pairs with codon on mRNA strand
What is the function of rRNA?—ANSWER-part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
,Feedback inhibition—ANSWER-Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases—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)—ANSWER-Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites—ANSWER-nt sequence where replication is initiated
Topoisomerase I—ANSWER-Induces ss breaks
Remove DNA supercoils during TXN and DNA replication; for strand breakage during
recombination; for chr condensation; and to disentangle intertwined DNA during mitosis
topoisomerase II—ANSWER-cuts both strands of one DNA double helix, passes another
unbroken DNA helix through it, and then reanneals the cut strands
Gyrase (topoisomerase II)—ANSWER-Unwinds supercoiling caused by unwinding at the rep
fork by introducing DSBs
Helicase—ANSWER-Breaks H-bonds of double helix at the replication fork
Primase—ANSWER-DNApol α (DNA dep RNA pol)
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law, Copyrighted By Brittie Donald
, adds short segments of complementary
RNA to ssDNA template (primers), serves as starting points for replication
single-strand DNA binding proteins (SSBPs)—ANSWER-Binds ssDNA and prevents it from re-
annealing during TXN, replication, repair, and recombination
Okazaki fragments—ANSWER-Short fragments of DNA synthesized by DNApol δ using the
lagging strand (3'->5') as a template
Ligase—ANSWER-Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication?—ANSWER-1. Initiate
2. Elongate
3. Terminate
Telomeres—ANSWER-Repeat sequence (TTAGGG) at the ends of chr, protect chr from
degradation
RNA polymerase—ANSWER-DNA dependent RNApol
Transcribes DNA template to RNA (3'-->5'; anti-parallel)
Splicesomes—ANSWER-Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers—ANSWER-Short regions of DNA that bind proteins (TXN factors) that enhance
TXN of a gene
Poly-A tail—ANSWER-Prevents mRNA from being degraded in cytoplasm
Certification Exam Questions and
Answers 100% PASS
Pyrimidine—ANSWER-One carbon ring
Cytosine, Thymine, Uracil
Purine—ANSWER-Two carbon rings
Adenine, Guanine
How are nucleotides joined together?—ANSWER-Condensation to form phosphodiester
bond
What is the function of mRNA?—ANSWER-Carries genetic info out of nucleus
Transcript translated to protein
What is the function of tRNA?—ANSWER-Carries aa to ribosome
Anticodon pairs with codon on mRNA strand
What is the function of rRNA?—ANSWER-part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
,Feedback inhibition—ANSWER-Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases—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)—ANSWER-Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites—ANSWER-nt sequence where replication is initiated
Topoisomerase I—ANSWER-Induces ss breaks
Remove DNA supercoils during TXN and DNA replication; for strand breakage during
recombination; for chr condensation; and to disentangle intertwined DNA during mitosis
topoisomerase II—ANSWER-cuts both strands of one DNA double helix, passes another
unbroken DNA helix through it, and then reanneals the cut strands
Gyrase (topoisomerase II)—ANSWER-Unwinds supercoiling caused by unwinding at the rep
fork by introducing DSBs
Helicase—ANSWER-Breaks H-bonds of double helix at the replication fork
Primase—ANSWER-DNApol α (DNA dep RNA pol)
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law, Copyrighted By Brittie Donald
, adds short segments of complementary
RNA to ssDNA template (primers), serves as starting points for replication
single-strand DNA binding proteins (SSBPs)—ANSWER-Binds ssDNA and prevents it from re-
annealing during TXN, replication, repair, and recombination
Okazaki fragments—ANSWER-Short fragments of DNA synthesized by DNApol δ using the
lagging strand (3'->5') as a template
Ligase—ANSWER-Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication?—ANSWER-1. Initiate
2. Elongate
3. Terminate
Telomeres—ANSWER-Repeat sequence (TTAGGG) at the ends of chr, protect chr from
degradation
RNA polymerase—ANSWER-DNA dependent RNApol
Transcribes DNA template to RNA (3'-->5'; anti-parallel)
Splicesomes—ANSWER-Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers—ANSWER-Short regions of DNA that bind proteins (TXN factors) that enhance
TXN of a gene
Poly-A tail—ANSWER-Prevents mRNA from being degraded in cytoplasm
