BIOL 4003 Exam 4 questions n
answers already passed
During the Ames test, if a substance is a mutagen, there will be _____ colonies on the plates in
which the cells had been exposed to the mutagen, because the mutagen converts some of the
cells from _____.
a. less, his+ to his-
b. more, his+ to his-
c. less, his- to his+
d. more, his- to his+ - ANS ✔✔d. more, his- to his+
Gene conversion may occur via
a. mismatch repair
b. gap repair synthesis
c. nucleotide excision repair
d. both a and b - ANS ✔✔d. both a (mismatch repair) and b (gap repair synthesis)
Which of the following events during homologous recombination is not the same between the
Holliday model and the double strand break model?
a. How the sister chromatids initially line up
b. How the DNA strands are cut
c. The process by which heteroduplexes are formed
,d. The separation of the DNA segments during the resolution step - ANS ✔✔b. How the DNA
strands are cut
A mutation changes a codon to another codon that does not change the original amino acid to a
different amino acid. This is a
a. silent mutation
b. missense mutation
c. nonsense mutation
d. frameshift mutation - ANS ✔✔a. silent mutation
During homologous recombination, what is a consequence of branch migration?
a. The resolution of the Holliday junction into two separate DNA molecules
b. The formation of a D loop
c. The formation of a heteroduplex
d. The initial breakage of the DNA at a single location in two different DNA strands - ANS ✔✔c.
The formation of a heteroduplex
Which of the following is a cause of spontaneous mutations?
a. 5-bromouracil used for chemotherapy
b. UV light
c. A tautomeric shift that cause mis-base pairing
d. A chemical such as nitrous acid that can change the structure of a base - ANS ✔✔c. A
tautomeric shift that causes mis-base pairing
, Which of the following proteins is/are used by a retrotransposon (retroelement), which is a
transposable element that moves via an RNA intermediate?
a. Reverse transcriptase
b. Transposase
c. Integrase
d. Both a and c - ANS ✔✔d. Both a (reverse transcriptase) and c (integrate)
Why does transposition via transposes produce direct repeats?
a. Transposase inserts repeats at both ends of the transposable element
b. Transposase makes staggered cuts that are filled in by DNA gap repair synthesis
c. Transposase causes one of the two inverted repeats to flip to the opposite direction
d. Transposase does both b and c - ANS ✔✔b. Transposase makes staggered cuts that are filled
in by DNA gap repair synthesis
Which of the following statements regarding retrotransposons is the most accurate?
a. Retrotransposons are most abundant in prokaryotic genomes
b. Retrotransposons are most abundant in the genomes of simple eukaryotic genomes, such as
yeast
c. Retrotransposons are most abundant in the genomes of complex, multicellular eukaryotes
d. Retrotransposons are very rarely found in genomes because they are eliminated via natural
selection - ANS ✔✔c. Retrotransposons are most abundant in the genomes of complex,
multicellular eukaryotes
In DNA repair by the nucleotide excision repair system, which of the following is not one of the
steps that occurs?
answers already passed
During the Ames test, if a substance is a mutagen, there will be _____ colonies on the plates in
which the cells had been exposed to the mutagen, because the mutagen converts some of the
cells from _____.
a. less, his+ to his-
b. more, his+ to his-
c. less, his- to his+
d. more, his- to his+ - ANS ✔✔d. more, his- to his+
Gene conversion may occur via
a. mismatch repair
b. gap repair synthesis
c. nucleotide excision repair
d. both a and b - ANS ✔✔d. both a (mismatch repair) and b (gap repair synthesis)
Which of the following events during homologous recombination is not the same between the
Holliday model and the double strand break model?
a. How the sister chromatids initially line up
b. How the DNA strands are cut
c. The process by which heteroduplexes are formed
,d. The separation of the DNA segments during the resolution step - ANS ✔✔b. How the DNA
strands are cut
A mutation changes a codon to another codon that does not change the original amino acid to a
different amino acid. This is a
a. silent mutation
b. missense mutation
c. nonsense mutation
d. frameshift mutation - ANS ✔✔a. silent mutation
During homologous recombination, what is a consequence of branch migration?
a. The resolution of the Holliday junction into two separate DNA molecules
b. The formation of a D loop
c. The formation of a heteroduplex
d. The initial breakage of the DNA at a single location in two different DNA strands - ANS ✔✔c.
The formation of a heteroduplex
Which of the following is a cause of spontaneous mutations?
a. 5-bromouracil used for chemotherapy
b. UV light
c. A tautomeric shift that cause mis-base pairing
d. A chemical such as nitrous acid that can change the structure of a base - ANS ✔✔c. A
tautomeric shift that causes mis-base pairing
, Which of the following proteins is/are used by a retrotransposon (retroelement), which is a
transposable element that moves via an RNA intermediate?
a. Reverse transcriptase
b. Transposase
c. Integrase
d. Both a and c - ANS ✔✔d. Both a (reverse transcriptase) and c (integrate)
Why does transposition via transposes produce direct repeats?
a. Transposase inserts repeats at both ends of the transposable element
b. Transposase makes staggered cuts that are filled in by DNA gap repair synthesis
c. Transposase causes one of the two inverted repeats to flip to the opposite direction
d. Transposase does both b and c - ANS ✔✔b. Transposase makes staggered cuts that are filled
in by DNA gap repair synthesis
Which of the following statements regarding retrotransposons is the most accurate?
a. Retrotransposons are most abundant in prokaryotic genomes
b. Retrotransposons are most abundant in the genomes of simple eukaryotic genomes, such as
yeast
c. Retrotransposons are most abundant in the genomes of complex, multicellular eukaryotes
d. Retrotransposons are very rarely found in genomes because they are eliminated via natural
selection - ANS ✔✔c. Retrotransposons are most abundant in the genomes of complex,
multicellular eukaryotes
In DNA repair by the nucleotide excision repair system, which of the following is not one of the
steps that occurs?
