ASCP Molecular Biology Exam Prep
Questions with Correct Answers 2025-2026
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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
What does mRNA do? - CORRECT ANSWER -carries code out of cell.
code for protein structure.
DNA to ribosomes
end of transcription start of translation
What does tRNA do? - CORRECT ANSWER -
decodes mRNA. Matches amino acids to mRNA code. Protein synthesis
What does rRNA do? - CORRECT ANSWER -part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
Feedback Inhibition - CORRECT ANSWER -end 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 nucleotide at a time
cleaves phosphodiester bond at end of chain
,5' ---> 3' and 3' ---> 5'
Endonucleases - CORRECT ANSWER -cleaves phoshpodiester bonds w/in chain
recognition site is palindromic sequence
cleaves unevenly, leaves sticky ends
(restriction enzymes)
DNA polymerase III - CORRECT ANSWER -
copies DNA by reading existing strand, builds new comp. strand
always adds to 3' end
can't start new strand on its own (ORI sites)
ORI sites - CORRECT ANSWER -origin of replication on chromosome
triggers DNA replication
gyrase - CORRECT ANSWER -unwinds DNA in front of fork
DNA polymerase I - CORRECT ANSWER -
removes RNA nucleotides form RNA primers and replaces with DNA
(makes sure primers that start replication are removed)
helicase - CORRECT ANSWER -breaks H-bonds of double helix
topoisomerase - CORRECT ANSWER -
breaks/ reseals DNA backbone to release tension caused by twisting
(DNA gyrase)
primase - CORRECT ANSWER -(RNA pol)
primers, small RNA, serves as starting points for copying DNA
helper enzyme for DNA pol III
, single-strand DNA-binding proteins (SSBPs) - CORRECT ANSWER -hold DNA open during replication
Okazaki fragments - CORRECT ANSWER -lagging strand
3' ---> 5'
away from fork
DNA pol III adds, DNA ligase closes gaps
Ligase - CORRECT ANSWER -closes gaps in DNA
forms covalent bonds b/w nucleotides, 3' end of new DNA to 5' end of growing chain
What are the steps in DNA replication? - CORRECT ANSWER -1. Initiate
2. Elongate
3. Terminate
Telomers - CORRECT ANSWER -cap ends of chromosome during replication to preserve DNA
-10 box - CORRECT ANSWER -TATA box (TATAAT)
located 10 bases away from transcription start site
promoter
RNA pol binding site
-35 box - CORRECT ANSWER -TTGACA
located 35 bases away from transcription start site
promoter
RNA Polymerase - CORRECT ANSWER -opens double helix
reads one strand to make RNA, 3' --> 5' (antiparallel)
DNA-dependant
Questions with Correct Answers 2025-2026
Save
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
What does mRNA do? - CORRECT ANSWER -carries code out of cell.
code for protein structure.
DNA to ribosomes
end of transcription start of translation
What does tRNA do? - CORRECT ANSWER -
decodes mRNA. Matches amino acids to mRNA code. Protein synthesis
What does rRNA do? - CORRECT ANSWER -part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
Feedback Inhibition - CORRECT ANSWER -end 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 nucleotide at a time
cleaves phosphodiester bond at end of chain
,5' ---> 3' and 3' ---> 5'
Endonucleases - CORRECT ANSWER -cleaves phoshpodiester bonds w/in chain
recognition site is palindromic sequence
cleaves unevenly, leaves sticky ends
(restriction enzymes)
DNA polymerase III - CORRECT ANSWER -
copies DNA by reading existing strand, builds new comp. strand
always adds to 3' end
can't start new strand on its own (ORI sites)
ORI sites - CORRECT ANSWER -origin of replication on chromosome
triggers DNA replication
gyrase - CORRECT ANSWER -unwinds DNA in front of fork
DNA polymerase I - CORRECT ANSWER -
removes RNA nucleotides form RNA primers and replaces with DNA
(makes sure primers that start replication are removed)
helicase - CORRECT ANSWER -breaks H-bonds of double helix
topoisomerase - CORRECT ANSWER -
breaks/ reseals DNA backbone to release tension caused by twisting
(DNA gyrase)
primase - CORRECT ANSWER -(RNA pol)
primers, small RNA, serves as starting points for copying DNA
helper enzyme for DNA pol III
, single-strand DNA-binding proteins (SSBPs) - CORRECT ANSWER -hold DNA open during replication
Okazaki fragments - CORRECT ANSWER -lagging strand
3' ---> 5'
away from fork
DNA pol III adds, DNA ligase closes gaps
Ligase - CORRECT ANSWER -closes gaps in DNA
forms covalent bonds b/w nucleotides, 3' end of new DNA to 5' end of growing chain
What are the steps in DNA replication? - CORRECT ANSWER -1. Initiate
2. Elongate
3. Terminate
Telomers - CORRECT ANSWER -cap ends of chromosome during replication to preserve DNA
-10 box - CORRECT ANSWER -TATA box (TATAAT)
located 10 bases away from transcription start site
promoter
RNA pol binding site
-35 box - CORRECT ANSWER -TTGACA
located 35 bases away from transcription start site
promoter
RNA Polymerase - CORRECT ANSWER -opens double helix
reads one strand to make RNA, 3' --> 5' (antiparallel)
DNA-dependant
