Transcript Ch 15 Clicker Question

CAMPBELL BIOLOGY IN FOCUS
URRY • CAIN • WASSERMAN • MINORSKY • REECE
15
Regulation of
Gene Expression
Questions prepared by
Douglas Darnowski, Indiana University Southeast
James Langeland, Kalamazoo College
Murty S. Kambhampati, Southern University at New Orleans
Roberta Batorsky, Temple University
© 2016 Pearson Education, Inc.
SECOND EDITION
What does the operon model attempt to explain?
A. the coordinated control of gene expression
in bacteria
B. bacterial resistance to antibiotics
C. how genes move between homologous regions of
DNA
D. the mechanism of viral attachment to a host cell
E. horizontal transmission of plant viruses
© 2016 Pearson Education, Inc.
What does the operon model attempt to explain?
A. the coordinated control of gene expression
in bacteria
B. bacterial resistance to antibiotics
C. how genes move between homologous regions of
DNA
D. the mechanism of viral attachment to a host cell
E. horizontal transmission of plant viruses
© 2016 Pearson Education, Inc.
When tryptophan (an amino acid) is present in the
external medium, the E. coli bacterium brings in the
tryptophan and does not need to make this amino acid.
Which is true when there is no tryptophan in the
medium?
A. The repressor is active and binds to the operator.
B. The repressor is inactive, and RNA polymerase moves
through the operator.
C. The operator is bound, and mRNA is made.
D. Genes are inactive.
E. The corepressor binds to the repressor.
© 2016 Pearson Education, Inc.
When tryptophan (an amino acid) is present in the
external medium, the E. coli bacterium brings in the
tryptophan and does not need to make this amino acid.
Which is true when there is no tryptophan in the
medium?
A. The repressor is active and binds to the operator.
B. The repressor is inactive, and RNA polymerase
moves through the operator.
C. The operator is bound, and mRNA is made.
D. Genes are inactive.
E. The corepressor binds to the repressor.
© 2016 Pearson Education, Inc.
Each of a group of E. coli bacterial cells has a mutation in
its lac operon. Which of these will make it impossible for
the cell to metabolize lactose?
A.
B.
C.
D.
mutation in lac (-galactosidase gene)
mutation in lac (cannot bind to operator)
mutation in operator (cannot bind to repressor)
mutation in lac (cannot bind to inducer)
© 2016 Pearson Education, Inc.
Each of a group of E. coli bacterial cells has a mutation in
its lac operon. Which of these will make it impossible for
the cell to metabolize lactose?
A.
B.
C.
D.
mutation in lac (-galactosidase gene)
mutation in lac (cannot bind to operator)
mutation in operator (cannot bind to repressor)
mutation in lac (cannot bind to inducer)
© 2016 Pearson Education, Inc.
A specific gene is known to code for three different but
related proteins. This could be due to which of the
following?
A.
B.
C.
D.
E.
premature mRNA degradation
alternative RNA splicing
use of different enhancers
protein degradation
differential transport
© 2016 Pearson Education, Inc.
A specific gene is known to code for three different but
related proteins. This could be due to which of the
following?
A.
B.
C.
D.
E.
premature mRNA degradation
alternative RNA splicing
use of different enhancers
protein degradation
differential transport
© 2016 Pearson Education, Inc.
Which methods would determine which genes are turned
on in a certain cell in an organism? (Choose more than
one answer.)
A. Use RT-PCR to identify what mRNAs are
present.
B. Use RT-PCR to measure what proteins are present.
C. Use a radioactive probe that binds only to
certain mRNAs.
D. Use a fluorescent probe that records DNA replication.
E. Use a fluorescent probe that binds to only
certain mRNAs.
© 2016 Pearson Education, Inc.
Which methods would determine which genes are turned
on in a certain cell in an organism? (Choose more than
one answer.)
A. Use RT-PCR to identify what mRNAs are
present.
B. Use RT-PCR to measure what proteins are present.
C. Use a radioactive probe that binds only to
certain mRNAs.
D. Use a fluorescent probe that records DNA replication.
E. Use a fluorescent probe that binds to only
certain mRNAs.
© 2016 Pearson Education, Inc.
Pair the following terms by their physical binding with
each other: promoter, operator, RNA polymerase,
repressor protein.
A. RNA polymerase with repressor protein, promoter with
operator
B. RNA polymerase with promoter; repressor protein with
operator
C. RNA polymerase with operator; repressor protein with
promoter
© 2016 Pearson Education, Inc.
Pair the following terms by their physical binding with
each other: promoter, operator, RNA polymerase,
repressor protein.
A. RNA polymerase with repressor protein, promoter with
operator
B. RNA polymerase with promoter; repressor protein
with operator
C. RNA polymerase with operator; repressor protein with
promoter
© 2016 Pearson Education, Inc.
Imagine an E. coli cell with a mutation that renders its trp
repressor protein completely inactive. Which of the
following would be true of that cell?
A. It synthesizes tryptophan only when tryptophan is
absent.
B. It never synthesizes tryptophan.
C. It always synthesizes tryptophan.
D. It synthesizes tryptophan only when tryptophan is
present.
© 2016 Pearson Education, Inc.
Imagine an E. coli cell with a mutation that renders its trp
repressor protein completely inactive. Which of the
following would be true of that cell?
A. It synthesizes tryptophan only when tryptophan is
absent.
B. It never synthesizes tryptophan.
C. It always synthesizes tryptophan.
D. It synthesizes tryptophan only when tryptophan is
present.
© 2016 Pearson Education, Inc.
In normal E. coli cells, under which of the following
conditions is the lac operon “ON”?
A.
B.
C.
D.
glucose present, lactose present
glucose absent, lactose absent
glucose present, lactose absent
glucose absent, lactose present
© 2016 Pearson Education, Inc.
In normal E. coli cells, under which of the following
conditions is the lac operon “ON”?
A.
B.
C.
D.
glucose present, lactose present
glucose absent, lactose absent
glucose present, lactose absent
glucose absent, lactose present
© 2016 Pearson Education, Inc.
In normal E. coli cells, in which the lac operon is “ON,”
which combination of CAP and lac repressor proteins is
bound to the lac operon?
A.
B.
C.
D.
both cap and lac repressor
neither cap nor lac repressor
only cap
only lac repressor
© 2016 Pearson Education, Inc.
In normal E. coli cells, in which the lac operon is “ON,”
which combination of CAP and lac repressor proteins is
bound to the lac operon?
A.
B.
C.
D.
both cap and lac repressor
neither cap nor lac repressor
only cap
only lac repressor
© 2016 Pearson Education, Inc.
Imagine an E. coli cell in which the lac operator has a
mutation that renders it unable to bind the lac repressor.
When would its lac operon be “ON”?
A.
B.
C.
D.
always
never
when glucose levels are low
only when glucose levels are low and lactose levels
are high
© 2016 Pearson Education, Inc.
Imagine an E. coli cell in which the lac operator has a
mutation that renders it unable to bind the lac repressor.
When would its lac operon be “ON”?
A.
B.
C.
D.
always
never
when glucose levels are low
only when glucose levels are low and lactose levels
are high
© 2016 Pearson Education, Inc.
Histone de-acetylases (HDACs) are enzymes that remove
acetyl groups from histone proteins. With regard to their
effects on transcription, HDACs should do which of the
following?
A.
B.
C.
D.
activate transcription by opening chromatin
activate transcription by condensing chromatin
repress transcription by opening chromatin
repress transcription by condensing chromatin
© 2016 Pearson Education, Inc.
Histone de-acetylases (HDACs) are enzymes that remove
acetyl groups from histone proteins. With regard to their
effects on transcription, HDACs should do which of the
following?
A.
B.
C.
D.
activate transcription by opening chromatin
activate transcription by condensing chromatin
repress transcription by opening chromatin
repress transcription by condensing chromatin
© 2016 Pearson Education, Inc.
Why is a myosin gene transcriptionally expressed in
muscle cells, but not in neurons?
A. Neurons lack an enhancer in the myosin gene.
B. Neurons lack the myosin gene.
C. Muscle cells have an extra enhancer in the myosin
gene.
D. Muscle cells express an activator protein that binds the
myosin enhancer.
© 2016 Pearson Education, Inc.
Why is a myosin gene transcriptionally expressed in
muscle cells, but not in neurons?
A. Neurons lack an enhancer in the myosin gene.
B. Neurons lack the myosin gene.
C. Muscle cells have an extra enhancer in the myosin
gene.
D. Muscle cells express an activator protein that
binds the myosin enhancer.
© 2016 Pearson Education, Inc.
A eukaryotic gene has a pre-mRNA with five exons (1, 2,
3, 4, 5). Which of the following arrangements of exons is
not possible in a mature mRNA due to alternative
splicing?
A.
B.
C.
D.
1, 2, 5
1, 3, 4, 5
1, 3, 2, 4, 5
1, 3, 3, 5
© 2016 Pearson Education, Inc.
A eukaryotic gene has a pre-mRNA with five exons (1, 2,
3, 4, 5). Which of the following arrangements of exons is
not possible in a mature mRNA due to alternative
splicing?
A.
B.
C.
D.
1, 2, 5
1, 3, 4, 5
1, 3, 2, 4, 5
1, 3, 3, 5
© 2016 Pearson Education, Inc.
A mi-RNA binds with perfect complementarity to a
target mRNA of gene X. What is/are the outcome(s) for
gene X in terms of gene regulation?
A.
B.
C.
D.
less gene X
less pre-mRNA of gene X
less mRNA of gene X
less protein of gene X
© 2016 Pearson Education, Inc.
A mi-RNA binds with perfect complementarity to a
target mRNA of gene X. What is/are the outcome(s) for
gene X in terms of gene regulation?
A.
B.
C.
D.
less gene X
less pre-mRNA of gene X
less mRNA of gene X
less protein of gene X
© 2016 Pearson Education, Inc.
A particular oncogene with the partial mRNA sequence
of 5ʹ AUG GAU GGG is expressed in certain cancer cells.
What partial DNA sequence would be part of an effective
probe to determine if this oncogene were being expressed
in cells?
A.
B.
C.
D.
5ʹ ATG GAT GGG
5ʹ GGG TAG GTA
5ʹ CCC ATC CAT
5ʹ TAC CTA CCC
© 2016 Pearson Education, Inc.
A particular oncogene with the partial mRNA sequence
of 5ʹ AUG GAU GGG is expressed in certain cancer cells.
What partial DNA sequence would be part of an effective
probe to determine if this oncogene were being expressed
in cells?
A.
B.
C.
D.
5ʹ ATG GAT GGG
5ʹ GGG TAG GTA
5ʹ CCC ATC CAT
5ʹ TAC CTA CCC
© 2016 Pearson Education, Inc.