CMB 352 Exam 3 With
Correct Answers
Which of the following statements correctly describes telomerase?
a) Telomerase carries its own DNA template
b) Inactivation of telomerase contributes to the extended lifespan of cancer
cells
c) Telomerase extends the 3'-ends of the lagging strand template of linear
chromosomes
d) Telomerase separates the circular daughter strands in E. coli DNA
replication
e) Telomerase unwinds the DNA in the pre-priming stage of DNA replication
- ANSWER c) Telomerase extends the 3'-ends of the lagging strand template
of linear chromosomes
In prokaryotic transcription, the role of the sigma factor is...
a) to catalyze the formation of phosphodiester bonds
b) to position RNA polymerase at a transcription start site
c) to release the completed transcript from the template DNA
d) to separate DNA strands during elongation
e) to terminate transcription at specific secondary structures - ANSWER b) to
,position RNA polymerase at a transcription start site
A fundamental difference between DNA polymerase I (Kornberg enzyme) and
DNA polymerase III is...
a) Pol I has a single catalytic site for DNA synthesis while Pol III has three
catalytic sites for DNA synthesis
b) Pol I consists of multiple polypeptide subunits while Pol III consists of a
single subunit
c) Pol I can synthesize both DNA and RNA while Pol III can only synthesis
DNA
d) Pol I has a low processivity and Pol III has high processivity
e) All of the above are true - ANSWER d) Pol I have low processivity and III
has high processivity
During elongation of protein synthesis the charged tRNA is always added at
the...
a) A site of the ribosome
b) P site of the ribosome
c) active site of the tRNA-aminoacyl synthetase
d) to the Shine-Dalgarno sequence
e) to the polyA tail of the mRNA transcript - ANSWER a) A site of the
ribosome
Which DNA polymerase is mainly responsible for genome replication in
eukaryotic cells?
, a) DNA polymerase a (alpha)
b) DNA polymerase I
c) DNA polymerase II
d) DNA polymerase III
e) DNA polymerase d (delta) - ANSWER e) DNA polymerase d (delta)
If the GC content of a DNA molecule is 60%, what are the percentages of the
four bases (G, C, T, A)?
a) G = 60%, C = 60%, A = 40%, T = 40%
b) G = 30%, C = 30%, A = 20%, T = 20%
c) G = 30%, A = 30%, C = 20%, T = 20%
d) G = 60%, C = 60%, A = 40%, U = 40%
e) G = 30%, C = 30%, A = 20%, U = 20% - ANSWER b) G = 30%, C = 30%, A =
20%, T = 20%
If you add thymidine 5' monophosphate in place of thymidine 5'
triphosphate in a DNA synthesis reaction, what would happen?
a) Leading strand synthesis would not occur
b) Lagging strand synthesis would not occur
c) Primase synthesis would not occur
d) DNA synthesis would be unaffected
e) A and B - ANSWER e) A and B
Correct Answers
Which of the following statements correctly describes telomerase?
a) Telomerase carries its own DNA template
b) Inactivation of telomerase contributes to the extended lifespan of cancer
cells
c) Telomerase extends the 3'-ends of the lagging strand template of linear
chromosomes
d) Telomerase separates the circular daughter strands in E. coli DNA
replication
e) Telomerase unwinds the DNA in the pre-priming stage of DNA replication
- ANSWER c) Telomerase extends the 3'-ends of the lagging strand template
of linear chromosomes
In prokaryotic transcription, the role of the sigma factor is...
a) to catalyze the formation of phosphodiester bonds
b) to position RNA polymerase at a transcription start site
c) to release the completed transcript from the template DNA
d) to separate DNA strands during elongation
e) to terminate transcription at specific secondary structures - ANSWER b) to
,position RNA polymerase at a transcription start site
A fundamental difference between DNA polymerase I (Kornberg enzyme) and
DNA polymerase III is...
a) Pol I has a single catalytic site for DNA synthesis while Pol III has three
catalytic sites for DNA synthesis
b) Pol I consists of multiple polypeptide subunits while Pol III consists of a
single subunit
c) Pol I can synthesize both DNA and RNA while Pol III can only synthesis
DNA
d) Pol I has a low processivity and Pol III has high processivity
e) All of the above are true - ANSWER d) Pol I have low processivity and III
has high processivity
During elongation of protein synthesis the charged tRNA is always added at
the...
a) A site of the ribosome
b) P site of the ribosome
c) active site of the tRNA-aminoacyl synthetase
d) to the Shine-Dalgarno sequence
e) to the polyA tail of the mRNA transcript - ANSWER a) A site of the
ribosome
Which DNA polymerase is mainly responsible for genome replication in
eukaryotic cells?
, a) DNA polymerase a (alpha)
b) DNA polymerase I
c) DNA polymerase II
d) DNA polymerase III
e) DNA polymerase d (delta) - ANSWER e) DNA polymerase d (delta)
If the GC content of a DNA molecule is 60%, what are the percentages of the
four bases (G, C, T, A)?
a) G = 60%, C = 60%, A = 40%, T = 40%
b) G = 30%, C = 30%, A = 20%, T = 20%
c) G = 30%, A = 30%, C = 20%, T = 20%
d) G = 60%, C = 60%, A = 40%, U = 40%
e) G = 30%, C = 30%, A = 20%, U = 20% - ANSWER b) G = 30%, C = 30%, A =
20%, T = 20%
If you add thymidine 5' monophosphate in place of thymidine 5'
triphosphate in a DNA synthesis reaction, what would happen?
a) Leading strand synthesis would not occur
b) Lagging strand synthesis would not occur
c) Primase synthesis would not occur
d) DNA synthesis would be unaffected
e) A and B - ANSWER e) A and B
