RUHS BSC NURSING MAIN EXAM IMPORTANT
QUESTUONSRUHS BSC MENTAL HEALTH
The proteins ________ work together to free the transcription factor that is bound
by the retinoblastoma protein. - ANSWER: p53 and cyclin
cyclin and E2F
cyclin and cyclin dependent kinase
p53 and p21
Mutated forms of the Rb protein - ANSWER: do not bind to E2F thereby inhibiting
cell division.
bind to E2F but have no effect on cell division.
do not bind to E2F thereby promoting uncontrolled cell division.
bind to E2F thereby inhibiting cell division.
The protein ________ checks for damaged DNA, thereby acting as a "quality control"
for the cell. - ANSWER: p53
What mutation would allow the cell to divide when it should not and could possibly
lead to cancer? - ANSWER: A mutation causing p53 to activate p21, even when it is
not necessary.
None of these will lead to cell proliferation.
A mutation preventing p21 from dissociating from cyclin.
A mutation causing p21 to remain active, even in the absence of a signal from p53.
Which mutation would allow the cell to pass the G1 checkpoint when it should not? -
ANSWER: A mutation in Rb, preventing it from associating with E2F.
A mutation in RB, preventing it from becoming phosphorylated.
A mutation in CDK, preventing in from phosphorylating Rb.
A mutation in Rb, preventing it from dissociating with E2F.
A cell has a mutation such that UvrA is permanently attached to UvrB. What effect
might this have on nucleotide excision repair (NER)? - ANSWER: -The cell would be
able to recognize damaged regions of the double helix, but it would be unable cut
the DNA in the appropriate region in preparation for removing the damaged
sequence.
For each of the following examples of mutations in the codon sequences of a gene,
predict the likely effect on the function of the polypeptide gene product (no effect
on function, weak effect, or strong effect). You will need to consult the genetic code
in Table 12.1. Note that the codons shown in the examples correspond to the coding
strand of the DNA—recall how the sequence of the coding strand relates to the
mRNA.
STRONG EFFECT
NO EFFECT
, WEAK EFFECT - ANSWER: -GAG-->GTG change in important part of the coding region
NOT NO
-CGA -->TGA near beginning of gene
NOT WEAK
-AAG-->AAA in middle of gene
NOT WEAK
-change of a codon for one acidic amino acid into another acidic amino acid
NOT STRONG
-insertion of one base (+1) shortly after start codon
NOT WEAK
-TGA -->TAA at end of coding region
NOT WEAK
-change of a C to a G before the ATG
NO EFFECT
.
Which of the following could not result from a mutation? - ANSWER: A fish in a
stream dies from a poison that blocks cellular respiration
The gene that codes for a certain caspase enzyme has a point mutation so that it can
no longer degrade certain proteins. This will result in - ANSWER: Silencing of a tumor
suppressor gene
Conversion of a proto-oncogene to an oncogene
Formation of an oncogene due to a viral infection
A gene encodes a protein that normally functions in promoting the programmed cell
death of blood cells that have accumulated damage to DNA. A mutation in this gene
can result in leukemia (cancer of the blood). This gene is an example of a/an -
ANSWER: tumor-suppressor gene.
The following are examples of changes in cell behavior. Determine whether they
could result in cancer (unregulated cell growth) or not.
COULD CAUSE CANCER
WOULD LIKELY NOT CAUSE CANCER - ANSWER: -loss of an essential checkpoint
protein
CANCER
-los of the tumor-suppressor p53
CANCER
QUESTUONSRUHS BSC MENTAL HEALTH
The proteins ________ work together to free the transcription factor that is bound
by the retinoblastoma protein. - ANSWER: p53 and cyclin
cyclin and E2F
cyclin and cyclin dependent kinase
p53 and p21
Mutated forms of the Rb protein - ANSWER: do not bind to E2F thereby inhibiting
cell division.
bind to E2F but have no effect on cell division.
do not bind to E2F thereby promoting uncontrolled cell division.
bind to E2F thereby inhibiting cell division.
The protein ________ checks for damaged DNA, thereby acting as a "quality control"
for the cell. - ANSWER: p53
What mutation would allow the cell to divide when it should not and could possibly
lead to cancer? - ANSWER: A mutation causing p53 to activate p21, even when it is
not necessary.
None of these will lead to cell proliferation.
A mutation preventing p21 from dissociating from cyclin.
A mutation causing p21 to remain active, even in the absence of a signal from p53.
Which mutation would allow the cell to pass the G1 checkpoint when it should not? -
ANSWER: A mutation in Rb, preventing it from associating with E2F.
A mutation in RB, preventing it from becoming phosphorylated.
A mutation in CDK, preventing in from phosphorylating Rb.
A mutation in Rb, preventing it from dissociating with E2F.
A cell has a mutation such that UvrA is permanently attached to UvrB. What effect
might this have on nucleotide excision repair (NER)? - ANSWER: -The cell would be
able to recognize damaged regions of the double helix, but it would be unable cut
the DNA in the appropriate region in preparation for removing the damaged
sequence.
For each of the following examples of mutations in the codon sequences of a gene,
predict the likely effect on the function of the polypeptide gene product (no effect
on function, weak effect, or strong effect). You will need to consult the genetic code
in Table 12.1. Note that the codons shown in the examples correspond to the coding
strand of the DNA—recall how the sequence of the coding strand relates to the
mRNA.
STRONG EFFECT
NO EFFECT
, WEAK EFFECT - ANSWER: -GAG-->GTG change in important part of the coding region
NOT NO
-CGA -->TGA near beginning of gene
NOT WEAK
-AAG-->AAA in middle of gene
NOT WEAK
-change of a codon for one acidic amino acid into another acidic amino acid
NOT STRONG
-insertion of one base (+1) shortly after start codon
NOT WEAK
-TGA -->TAA at end of coding region
NOT WEAK
-change of a C to a G before the ATG
NO EFFECT
.
Which of the following could not result from a mutation? - ANSWER: A fish in a
stream dies from a poison that blocks cellular respiration
The gene that codes for a certain caspase enzyme has a point mutation so that it can
no longer degrade certain proteins. This will result in - ANSWER: Silencing of a tumor
suppressor gene
Conversion of a proto-oncogene to an oncogene
Formation of an oncogene due to a viral infection
A gene encodes a protein that normally functions in promoting the programmed cell
death of blood cells that have accumulated damage to DNA. A mutation in this gene
can result in leukemia (cancer of the blood). This gene is an example of a/an -
ANSWER: tumor-suppressor gene.
The following are examples of changes in cell behavior. Determine whether they
could result in cancer (unregulated cell growth) or not.
COULD CAUSE CANCER
WOULD LIKELY NOT CAUSE CANCER - ANSWER: -loss of an essential checkpoint
protein
CANCER
-los of the tumor-suppressor p53
CANCER
