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MMSC490 Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
During E. coli DNA replication, all newly synthesized or nascent DNA
fragments must have one of the following characteristics
a. a 5' hydroxyl and 3' triphosphate
b. a 5' triphosphate and 3' monophosphate
c. 5' monophosphate and 3' hydroxyl
d. 5' triphosphate and 3' hydroxyl
Ans: d. 5' triphosphate and 3' hydroxyl
Among the 3 DNA polymerases in E. coli, DNA polymerases I and III
differ in a number of properties that make DNA polymerase III a more
suitable enzyme for chromosomal DNA synthesis. Which of the
following is an important difference between the 2:
a. DNA polymerase I does not require DNA template
b. they require different sets of deoxynucleotides
c. they differ in processivity
d. DNA polymerase I is involved only in DNA repair
Ans: c. they differ in processivity
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DNA replication requires the presence of a suitable template and a free
3'-OH end. this end may be generated by
a. binding of terminal nucleotide-carrying protein to 3' end of the
template
b. Syntheses of an RNA primer at origin or at Okazaki fragment start
points
c. nicking of one strand of the duplex DNA followed by strand
displacement
d. Loop formation at the 3' end (self-priming)
e. all of the above
Ans: e. all of the above
Although E. coli DNA polymerase I is not a chromosomal DNA
replicase, it participates in DNA replication. What is its function?
a. synthesizes Okazaki fragments
b. replaces RNA primer with DNA
c. unwinds the double helix
d. synthesizes an RNA primer
e. connects 3' end of one okazaki fragment with the 5' end of another
Ans: b. replaces RNA primer with DNA
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In a replication fork, how do leading and lagging strands differ?
a. lagging strand is subject to more error and requires more repair
b. lagging stand new DNA is synthesized 3' to 5'
c. each strand is replicated by a unique type of polymerase
d. lagging strand is replicated discontinuously
e. DNA polymerase proceeds more slowly on lagging strand
Ans: d. lagging strand is replicated discontinuously
In bacteria, mRNAs are...
a. completely transcribed first then translated completely before being
degraded
b. transcribed and translated simultaneously
c. completely transcribed first, then translated and degraded
simultaneously
d. transcribed, translated and degraded in different parts of cell
e. transcribed and translated simultaneously, then later degraded
Ans: b. transcribed and translated simultaneously
Combined sizes of prokaryotic and eukaryotic ribosomes are...
a. the same
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b. 30s and 50s, respectively
c. 40s and 60s respectively
d. 70s and 80s, respectively
Ans: d. 70s and 80s, respectively
Eukaryotic ribosomes recognize and initially bind to what structure on
the mRNA?
a. A shine-dalgarno sequence
b. the 7-methylguanosine cap
c. a TATA sequence
d. a CCAAT sequence
Ans: b. the 7-methylguanosine cap
Ribosome release factors are structurally similar to
a. the EF-Tu.aminoacyl-tRNA complex
b. EF-G.C.
c. tRNAs
d. both the EF-Tu.aminoacyl-tRNA complex and EF-G
e. the EF-Tu.aminoacyl-tRNA complex, EF-G and deacylated tRNAs
All rights reserved © 2025/ 2026 |
MMSC490 Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
During E. coli DNA replication, all newly synthesized or nascent DNA
fragments must have one of the following characteristics
a. a 5' hydroxyl and 3' triphosphate
b. a 5' triphosphate and 3' monophosphate
c. 5' monophosphate and 3' hydroxyl
d. 5' triphosphate and 3' hydroxyl
Ans: d. 5' triphosphate and 3' hydroxyl
Among the 3 DNA polymerases in E. coli, DNA polymerases I and III
differ in a number of properties that make DNA polymerase III a more
suitable enzyme for chromosomal DNA synthesis. Which of the
following is an important difference between the 2:
a. DNA polymerase I does not require DNA template
b. they require different sets of deoxynucleotides
c. they differ in processivity
d. DNA polymerase I is involved only in DNA repair
Ans: c. they differ in processivity
All rights reserved © 2025/ 2026 |
, Page |2
DNA replication requires the presence of a suitable template and a free
3'-OH end. this end may be generated by
a. binding of terminal nucleotide-carrying protein to 3' end of the
template
b. Syntheses of an RNA primer at origin or at Okazaki fragment start
points
c. nicking of one strand of the duplex DNA followed by strand
displacement
d. Loop formation at the 3' end (self-priming)
e. all of the above
Ans: e. all of the above
Although E. coli DNA polymerase I is not a chromosomal DNA
replicase, it participates in DNA replication. What is its function?
a. synthesizes Okazaki fragments
b. replaces RNA primer with DNA
c. unwinds the double helix
d. synthesizes an RNA primer
e. connects 3' end of one okazaki fragment with the 5' end of another
Ans: b. replaces RNA primer with DNA
All rights reserved © 2025/ 2026 |
, Page |3
In a replication fork, how do leading and lagging strands differ?
a. lagging strand is subject to more error and requires more repair
b. lagging stand new DNA is synthesized 3' to 5'
c. each strand is replicated by a unique type of polymerase
d. lagging strand is replicated discontinuously
e. DNA polymerase proceeds more slowly on lagging strand
Ans: d. lagging strand is replicated discontinuously
In bacteria, mRNAs are...
a. completely transcribed first then translated completely before being
degraded
b. transcribed and translated simultaneously
c. completely transcribed first, then translated and degraded
simultaneously
d. transcribed, translated and degraded in different parts of cell
e. transcribed and translated simultaneously, then later degraded
Ans: b. transcribed and translated simultaneously
Combined sizes of prokaryotic and eukaryotic ribosomes are...
a. the same
All rights reserved © 2025/ 2026 |
, Page |4
b. 30s and 50s, respectively
c. 40s and 60s respectively
d. 70s and 80s, respectively
Ans: d. 70s and 80s, respectively
Eukaryotic ribosomes recognize and initially bind to what structure on
the mRNA?
a. A shine-dalgarno sequence
b. the 7-methylguanosine cap
c. a TATA sequence
d. a CCAAT sequence
Ans: b. the 7-methylguanosine cap
Ribosome release factors are structurally similar to
a. the EF-Tu.aminoacyl-tRNA complex
b. EF-G.C.
c. tRNAs
d. both the EF-Tu.aminoacyl-tRNA complex and EF-G
e. the EF-Tu.aminoacyl-tRNA complex, EF-G and deacylated tRNAs
All rights reserved © 2025/ 2026 |
