1) Occasionally a person is found to have one blue eye and one brown eye. This is caused by the creation of a new mutation. In which cell did the mutation occur?
a) somatic cell of that person
b) germ cell of that person
c) germ cell of that person’s parent
d) somatic cell of that person’s parent
2) Consider the following list.. How many are proteins that can negatively regulate expression of a target gene?
Gal80 AraC lacZ TrpR
LacO CAP Gal4 Gal7
a) 1
b) 2
c) 3
d) 4
e) 5
3) Which statement is true about DNA methylation in eukaryotes?
a) it is used to regulate DNA replication
b) it is used to regulate protein translation
c) it is used to regulate mutation repair
d) it is used to regulate heterochromatin spreading
e) it is used to regulate transcription
4) Which statement is true about DNA methylation in prokaryotes?
a) it is used to regulate DNA replication
b) it is used to regulate heterochromatin spreading
c) it is used to regulate mutation repair
d) it is used to regulate transcription
e) it is used to regulate protein translation
5) Nondisjunction of chromosomes in meiosis may take place at the first or the second meiotic
division.If nondisjunction of the XY pair of chromosomes took place at the first division in the
formation of sperm,which of the following chromosomal types of sperm could be formed?
a) XY
b) YY
c) Y
d) XX
e) X
6) Which is a true difference between miRNA and siRNAs?
a) miRNAs are processed by Dicer, siRNA are usually not
b) miRNAs are found in the RISC complex, siRNAs are usually not
c) siRNAs are found in the RISC complex, miRNAs are usually not
d) siRNAs are processed by Dicer, miRNAs are usually not
e) miRNAs are transcribed from the genome, siRNAs are usually not
7) Consider two transposons in yeast, Ty3 and TyZ. The DNA sequence for each contains a single
gene interrupted by an intron. The Ty elements are allowed to transpose to new locations in the
yeast genome. When their DNA sequence is determined in the new location, Ty3 has no intron,
and TyZ has an intron. Is either of these Ty elements a retrotransposon?
a) neither Ty3 nor TyZ is a retrotransposon
b) both Ty3 and TyZ are retrotransposons
c) TyZ is a retrotransposon
d) Ty3 is a retrotransposon
e) there is not enough information to tell
8) What effect would a mutation in the gene encoding CAP have on expression of the lac and ara
operons in E. coli?
a) expression of ara would decrease; xpression of lac would be unaffcted
b) expression of lac would decrease; expression of ara would be unaffected
c) they could no longer be repressed and would be constituively expressed
d) they could no longer be strongly activated in the presence of inducer
e) they could no longer be strongly activated in the absence of inducer
9)
Nonhomologous chromosomes that have exchanged segments are the products of a
a) pericentric inversion
b) reciprocal translocation
c) paracentric inversion
d) double deletion
e) transposon insertion
10) Ethyl methane sulfonate (EMS) is an alkylating agent. The mechanism of action of this type of
mutagen is
a) slipping between the bases of the DNA
b) cleaving the base off a nucleotide
c) breaking the sugar-phosphate backbone
d) adding a chemical group to DNA bases
e) removing a chemical group from the DNA bases
11) If the two Trp codons in the leader of the trp operon were changed to codons for His, what would
be the consequence for regulation of the trp operon?
a) the trp operon would now be constitutively expressed
b) expression of the trp operon would now be under transcriptional control by
the His Repressor protein
c) expression of the trp operon would show attenuation when levels of
histidine in the cell were low
d) two of the above
e) all of the above
12) Which prokaryotic transcription factor does the yeast factor GAL4 most resemble in its mode of
action of regulating gene expressing?
a) Lac Repressor
b) AraC
c) Rho
d) CAP
e) Trp Repressor