_______ 5. The repressor protein of the lac operon has two different recognition and binding sites for other molec
Posted: Tue May 17, 2022 1:32 pm
_______
5. The repressor protein of the lac
operon has two different recognition and binding sites for other
molecules. Which of the following pairs of molecules do you think
is likely that these sites would bind?
a
a DNA sequence on the promoter and lactose
b
RNA polymerase and the corepressor
c
a DNA sequence on the operator and lactose
d
RNA polymerase and lactose
e
lactose and DNA polymerase
_____
6. In the presence of high cellular
concentrations of tryptophan
a
the repressor attaches to the DNA, but transcription
proceeds
b
the repressor binds to tryptophan and then leaves the
operator
c
tryptophan binds to the operator and prevents transcription
d
tryptophan binds to the repressor, which than binds to the
operator
e
tryptophan binds to the repressor, which binds to the promoter
and prevents transcription
_____
7. The operator of the lac operon is
'upstream' of the genes, which codes for enzymes. 'Upstream'
means
a
the operator is in the first part of the lacZ gene
b
the operator is crossed by RNA polymerase before RNA polymerase
reaches the genes, which code for enzymes
c
the operator is crossed by RNA polymerase before RNA polymerase
crosses the promoter
d
the operator is separated from the lacZ gene by
thousands of bases
e
an intron separates the operator and the genes, which code for
enzymes
______
8. One of the functions of the polyadenine tail
that is added to mRNA in eukaryotic cells is to
a
prevent degradation of the mRNA
b
initiate the binding of the mRNA to the ribosome
c
help the mRNA to bind to a pore in the nuclear membrane
d
add a specific amino acid sequence to the polypeptide
produced
e
act as a signal for the termination of translation
______
9. A certain protein needs to have a high energy
phosphate group added to it in the cytoplasm before it becomes
active. This offers the possibility of control at which of the
following levels?
a
Transcriptional
d
translational
b
Operational
e
posttranslational
c
post-transcriptional
10. The 'one gene:
one polypeptide' hypothesis had to be refined because some
genes
a.
code for primary transcripts that are alternatively spliced
producing multiple polypeptides
b.
code for many enzymes
c.
code for primary transcripts that include multiple introns
d.
code for primary transcripts that include multiple promoters
5. The repressor protein of the lac
operon has two different recognition and binding sites for other
molecules. Which of the following pairs of molecules do you think
is likely that these sites would bind?
a
a DNA sequence on the promoter and lactose
b
RNA polymerase and the corepressor
c
a DNA sequence on the operator and lactose
d
RNA polymerase and lactose
e
lactose and DNA polymerase
_____
6. In the presence of high cellular
concentrations of tryptophan
a
the repressor attaches to the DNA, but transcription
proceeds
b
the repressor binds to tryptophan and then leaves the
operator
c
tryptophan binds to the operator and prevents transcription
d
tryptophan binds to the repressor, which than binds to the
operator
e
tryptophan binds to the repressor, which binds to the promoter
and prevents transcription
_____
7. The operator of the lac operon is
'upstream' of the genes, which codes for enzymes. 'Upstream'
means
a
the operator is in the first part of the lacZ gene
b
the operator is crossed by RNA polymerase before RNA polymerase
reaches the genes, which code for enzymes
c
the operator is crossed by RNA polymerase before RNA polymerase
crosses the promoter
d
the operator is separated from the lacZ gene by
thousands of bases
e
an intron separates the operator and the genes, which code for
enzymes
______
8. One of the functions of the polyadenine tail
that is added to mRNA in eukaryotic cells is to
a
prevent degradation of the mRNA
b
initiate the binding of the mRNA to the ribosome
c
help the mRNA to bind to a pore in the nuclear membrane
d
add a specific amino acid sequence to the polypeptide
produced
e
act as a signal for the termination of translation
______
9. A certain protein needs to have a high energy
phosphate group added to it in the cytoplasm before it becomes
active. This offers the possibility of control at which of the
following levels?
a
Transcriptional
d
translational
b
Operational
e
posttranslational
c
post-transcriptional
10. The 'one gene:
one polypeptide' hypothesis had to be refined because some
genes
a.
code for primary transcripts that are alternatively spliced
producing multiple polypeptides
b.
code for many enzymes
c.
code for primary transcripts that include multiple introns
d.
code for primary transcripts that include multiple promoters