ASCP Molecular Biology Certification
Exam | Latest 2025 Questions With
100% Correct Answers Latest Update
Pyrimidine --CORRECT ANSWER--
One carbon ring Cytosine, Thymine,
Uracil
Purine --CORRECT ANSWER--Two
carbon rings Adenine, Guanine
How are nucleotides joined together? --CORRECT ANSWER--Condensation to form
phosphodiester bond
What is the function of mRNA? --CORRECT ANSWER--Carries genetic info
out of nucleus Transcript translated to protein
What is the function of tRNA? --CORRECT ANSWER--
Carries aa to ribosome Anticodon pairs with codon on mRNA
strand
What is the function of rRNA? --CORRECT ANSWER--part
of ribosome structure most abundant RNA
coordinated coupling of tRNA to mRNA codons
,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
Topoisomerase I --CORRECT 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 --CORRECT 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) --CORRECT ANSWER--Unwinds supercoiling caused by unwinding
at the rep fork by introducing DSBs
, Helicase --CORRECT ANSWER--Breaks H-bonds of double helix at the replication fork
Primase --CORRECT ANSWER--DNApol α
(DNA dep RNA pol) adds short segments of
complementary
RNA to ssDNA template (primers), serves as starting points for replication
single-strand DNA binding proteins (SSBPs) --CORRECT ANSWER--Binds ssDNA and
prevents it from re- annealing during TXN, replication, repair, and recombination
Okazaki fragments --CORRECT ANSWER--Short fragments of DNA synthesized by DNApol δ
using the lagging strand (3'->5') as a template
Ligase --CORRECT ANSWER--Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication? --CORRECT ANSWER--1. Initiate
2. Elongate
3. Terminate
Telomeres --CORRECT ANSWER--Repeat sequence (TTAGGG) at the ends of chr, protect chr
from degradation
RNA polymerase --CORRECT ANSWER--DNA dependent RNApol
Exam | Latest 2025 Questions With
100% Correct Answers Latest Update
Pyrimidine --CORRECT ANSWER--
One carbon ring Cytosine, Thymine,
Uracil
Purine --CORRECT ANSWER--Two
carbon rings Adenine, Guanine
How are nucleotides joined together? --CORRECT ANSWER--Condensation to form
phosphodiester bond
What is the function of mRNA? --CORRECT ANSWER--Carries genetic info
out of nucleus Transcript translated to protein
What is the function of tRNA? --CORRECT ANSWER--
Carries aa to ribosome Anticodon pairs with codon on mRNA
strand
What is the function of rRNA? --CORRECT ANSWER--part
of ribosome structure most abundant RNA
coordinated coupling of tRNA to mRNA codons
,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
Topoisomerase I --CORRECT 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 --CORRECT 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) --CORRECT ANSWER--Unwinds supercoiling caused by unwinding
at the rep fork by introducing DSBs
, Helicase --CORRECT ANSWER--Breaks H-bonds of double helix at the replication fork
Primase --CORRECT ANSWER--DNApol α
(DNA dep RNA pol) adds short segments of
complementary
RNA to ssDNA template (primers), serves as starting points for replication
single-strand DNA binding proteins (SSBPs) --CORRECT ANSWER--Binds ssDNA and
prevents it from re- annealing during TXN, replication, repair, and recombination
Okazaki fragments --CORRECT ANSWER--Short fragments of DNA synthesized by DNApol δ
using the lagging strand (3'->5') as a template
Ligase --CORRECT ANSWER--Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication? --CORRECT ANSWER--1. Initiate
2. Elongate
3. Terminate
Telomeres --CORRECT ANSWER--Repeat sequence (TTAGGG) at the ends of chr, protect chr
from degradation
RNA polymerase --CORRECT ANSWER--DNA dependent RNApol
