MMSC 491 Exam 2 Questions and Answers
Question 1
Purifying selection results in which of the following?
A. Removes harmful alleles from the population
B. Amplifies genes which can compensate for the loss of function mutant allele
C. Increases the frequency of a fitness conferring gene in the population
D. The process by which DNA is purified to carry out genetic testing.
Correct Answer
A
Question 2
With respect to histone modifications, which, if any, of the following statements, is
true?
A. histone acetylation always means adding an acetyl group to the side chain of a
lysine residue.
B. in histone acetylation each lysine of the histone is acetylated.
C. in histone phosphorylation a phosphate group is transferred to the side chain of a
serine .
D. in histone methylation it is the DNA that coils around a nucleosome that is
methylated, not the histone itself.
Correct Answer
A
Page 1 of 17
,Question 3
With respect to noncoding RNA (ncRNA) , which, if any, of the following statements, is
false?
A. Many long noncoding RNAs work in epigenetic regulation of gene expression.
B. Most regulatory long ncRNAs work as trans-acting regulators.
C. HOTAIR RNA is produced by a gene in the HOXC homeobox gene cluster at 12q13
but can regulate multiple genes within the HOXD gene cluster on chromosome 2.
D. HOTAIR RNA works as a scaffold that binds specific protein regulators at its two
ends.
Correct Answer
B
Question 4
Which of the following is a disease whose molecular basis is an unstable expansion of
short noncoding tandem repeats?
A. Kennedy disease
B. Huntington disease
C. Prader-Willi syndrome
D. Fragile X syndrome
Correct Answer
D
Question 5
With respect to X-linked dominant inheritance, which, if any, of the following
statements is false?
A. There are significantly more affected females than males.
B. Each child born to an affected mother has a risk of 1 in 2 of being affected.
C. Each daughter born to an affected father has a risk of 1 in 2 of being affected.
D. Each boy born to an affected father has a negligible risk of being affected.
Correct Answer
C
Page 2 of 17
, Question 6
Which, if any, of the following statements is false regarding genome editing?
A. Genome editing means making a predetermined change to the nucleotide
sequence at just one locus within an intact cell.
B. The specificity of genome editing depends on an initial site-specific cleavage of
double-stranded DNA following base pairing with specifically designed nucleotide
sequences.
C. Genome editing has the potential to permit specific "gene correction" in which a
mutant sequence in a cell is restored to the normal sequence.
D. Genome editing might also have therapeutic potential by specifically inactivating a
gene in some cases.
Correct Answer
B
Question 7
With respect to mosaicism, which, if any, of the following statements, is false?
A. Any person who has two or more cells that have a different genetic constitution is a
mosaic
B. All women are genetic mosaics
C. Every person is a genetic mosaic.
D. Mosaicism is the inevitable consequence of germline mutations.
Correct Answer
D
Question 8
A mutation that does not cause a disease but that is unstable at mitosis and meiosis
and can change into a pathogenic mutation.
A. a post-zygotic (somatic) mutation
B. a missense mutation
C. a dynamic mutation
D. a premutation
Correct Answer
D
Page 3 of 17
Question 1
Purifying selection results in which of the following?
A. Removes harmful alleles from the population
B. Amplifies genes which can compensate for the loss of function mutant allele
C. Increases the frequency of a fitness conferring gene in the population
D. The process by which DNA is purified to carry out genetic testing.
Correct Answer
A
Question 2
With respect to histone modifications, which, if any, of the following statements, is
true?
A. histone acetylation always means adding an acetyl group to the side chain of a
lysine residue.
B. in histone acetylation each lysine of the histone is acetylated.
C. in histone phosphorylation a phosphate group is transferred to the side chain of a
serine .
D. in histone methylation it is the DNA that coils around a nucleosome that is
methylated, not the histone itself.
Correct Answer
A
Page 1 of 17
,Question 3
With respect to noncoding RNA (ncRNA) , which, if any, of the following statements, is
false?
A. Many long noncoding RNAs work in epigenetic regulation of gene expression.
B. Most regulatory long ncRNAs work as trans-acting regulators.
C. HOTAIR RNA is produced by a gene in the HOXC homeobox gene cluster at 12q13
but can regulate multiple genes within the HOXD gene cluster on chromosome 2.
D. HOTAIR RNA works as a scaffold that binds specific protein regulators at its two
ends.
Correct Answer
B
Question 4
Which of the following is a disease whose molecular basis is an unstable expansion of
short noncoding tandem repeats?
A. Kennedy disease
B. Huntington disease
C. Prader-Willi syndrome
D. Fragile X syndrome
Correct Answer
D
Question 5
With respect to X-linked dominant inheritance, which, if any, of the following
statements is false?
A. There are significantly more affected females than males.
B. Each child born to an affected mother has a risk of 1 in 2 of being affected.
C. Each daughter born to an affected father has a risk of 1 in 2 of being affected.
D. Each boy born to an affected father has a negligible risk of being affected.
Correct Answer
C
Page 2 of 17
, Question 6
Which, if any, of the following statements is false regarding genome editing?
A. Genome editing means making a predetermined change to the nucleotide
sequence at just one locus within an intact cell.
B. The specificity of genome editing depends on an initial site-specific cleavage of
double-stranded DNA following base pairing with specifically designed nucleotide
sequences.
C. Genome editing has the potential to permit specific "gene correction" in which a
mutant sequence in a cell is restored to the normal sequence.
D. Genome editing might also have therapeutic potential by specifically inactivating a
gene in some cases.
Correct Answer
B
Question 7
With respect to mosaicism, which, if any, of the following statements, is false?
A. Any person who has two or more cells that have a different genetic constitution is a
mosaic
B. All women are genetic mosaics
C. Every person is a genetic mosaic.
D. Mosaicism is the inevitable consequence of germline mutations.
Correct Answer
D
Question 8
A mutation that does not cause a disease but that is unstable at mitosis and meiosis
and can change into a pathogenic mutation.
A. a post-zygotic (somatic) mutation
B. a missense mutation
C. a dynamic mutation
D. a premutation
Correct Answer
D
Page 3 of 17
