Question 1

One way that a promoter differs from an enhancer is that it

Accepted Answer

A)  is not a sequence of DNA. 
B)  does not bind a transcription factor. 
C)  is not located far away from the gene it regulates. 
D)  does not bind to an RNA polymerase. 
A)  is not a sequence of DNA. 
B)  does not bind a transcription factor. 
C)  is not located far away from the gene it regulates. 
D)  does not bind to an RNA polymerase.

Question 2

A reporter gene is used to

Accepted Answer

A)  identify regulatory sequences from the upstream regions of other genes. 
B)  determine if a protein binds to a given sequence element. 
C)  determine if a gene contains introns. 
D)  determine the stability of a protein. 
A)  identify regulatory sequences from the upstream regions of other genes. 
B)  determine if a protein binds to a given sequence element. 
C)  determine if a gene contains introns. 
D)  determine the stability of a protein.

Question 3

A researcher hypothesizes that expression of a particular gene is under positive transcriptional control. What evidence would support his hypothesis?

Accepted Answer

A)  A repressor protein is discovered that blocks transcription of this gene. 
B)  The gene is only expressed when catabolite activator protein binds to an upstream DNA site. 
C)  The gene is no longer regulated when an upstream DNA region undergoes mutation. 
D)  Mutation of the gene itself does not affect its regulation. 
A)  A repressor protein is discovered that blocks transcription of this gene. 
B)  The gene is only expressed when catabolite activator protein binds to an upstream DNA site. 
C)  The gene is no longer regulated when an upstream DNA region undergoes mutation. 
D)  Mutation of the gene itself does not affect its regulation.

Question 4

In eukaryotic cells, genes with methylated DNA tend to be more active than unmethylated genes.

Accepted Answer

A) True 
 B)False

Question 5

A researcher has several transcription factors in purified form as well as a DNA fragment in purified form. He suspects the DNA fragment binds to one of the transcription factors. He can use the _______ technique to determine which transcription factor the DNA fragment binds to.

Accepted Answer

electropho

Question 6

Which rationale best describes the ability of an enhancer to mediate transcription from very distant sites?

Accepted Answer

A)  Looping of the DNA can occur, allowing the transcription factor to come into proximity of the RNA polymerase. 
B)  When needed, enhancers are spliced into a region closer to the promoter. 
C)  They are recognized by RNA polymerase, which binds to the enhancers and then slides down the promoter toward the gene. 
D)  All of the above 
A)  Looping of the DNA can occur, allowing the transcription factor to come into proximity of the RNA polymerase. 
B)  When needed, enhancers are spliced into a region closer to the promoter. 
C)  They are recognized by RNA polymerase, which binds to the enhancers and then slides down the promoter toward the gene. 
D)  All of the above

Question 7

lncRNAs act as scaffolds to support proteins that regulate

Accepted Answer

A)  chromatin modification. 
B)  RNA polymerase binding to promoters. 
C)  looping of DNA to bring enhancers in proximity to transcription initiation complexes. 
D)  recruitment of Mediator to transcription complexes. 
A)  chromatin modification. 
B)  RNA polymerase binding to promoters. 
C)  looping of DNA to bring enhancers in proximity to transcription initiation complexes. 
D)  recruitment of Mediator to transcription complexes.

Question 8

In the 1960s, scientists discovered that acetylation of histones was correlated with increased transcription of chromatin. However, it took another 30 years before evidence was found that allowed scientists to say that acetylation was directly responsible for activating regions of chromatin for transcription. What was this evidence, and why did it provide a direct link between histone acetylation and gene activation?

Accepted Answer

The evidence was from an experiment in w

Question 9

Some chromatin remodeling factors use energy from ATP hydrolysis to slide histones along a chromosome. Explain how this type of activity can regulate gene expression.

Accepted Answer

When DNA is wound around histones, it is

Question 10

Which statement about epigenetic changes is true?

Accepted Answer

A)  They alter the base sequences within genes. 
B)  They cannot be passed from one generation to the next. 
C)  They always lead to activation of gene expression. 
D)  They can be reversed. 
A)  They alter the base sequences within genes. 
B)  They cannot be passed from one generation to the next. 
C)  They always lead to activation of gene expression. 
D)  They can be reversed.

Question 11

What are three ways in which an enhancer's function differs from that of a promoter?

Accepted Answer

An enhancer can (1) act at great distanc

Question 12

After they had germinated and sent up shoots, a group of plants was induced to take up the cytosine analog azacytosine, which cannot be methylated. Compared to control plants that were not treated with the analog, these plants produced many more flower stalks displaying flowers that had odd shapes. How can these results be explained?

Accepted Answer

Methylation of DNA must be involved in r

Question 13

An investigation identified whether histones nearest specific genes were acetylated or deacetylated. The results are summarized in the table below. Based on these results, it can be predicted that genes _______ would be actively expressed, while the others would not.
 $$\begin{array} { | c | c | c | c | c | c | } 
\hline & \text { Gene A } & \text { Gene B } & \text { Gene C } & \text { Gene D } & \text { Gene E } \
\hline \begin{array} { c } 
\text { Nearest } \
\text { histones }
\end{array} & \text { deacetylated } & \text { acetylated } & \text { deacetylated } & \text { deacetylated } & \text { acetylated } \
\hline
\end{array}$$

Accepted Answer

The answer of An investigation identified whether histones nearest specific...

Question 14

Prokaryotes are single-celled organisms and do not undergo differentiation. Why is it important that these cells have gene regulatory mechanisms, some of which repress transcription and others that stimulate transcription?

Accepted Answer

Prokaryotes must use their available ene

Question 15

Which is not a type of histone modification used for controlling gene expression?

Accepted Answer

A)  C-terminal amidation 
B)  Arginine methylation 
C)  Lysine ubiquitination 
D)  Serine phosphorylation 
A)  C-terminal amidation 
B)  Arginine methylation 
C)  Lysine ubiquitination 
D)  Serine phosphorylation

Question 16

A research group working with E. coli isolated several lac operon mutants. The group measured $\beta$-galactosidase activity under different environmental conditions, as shown in the table below. Which statement draws a plausible conclusion about one of these mutants?
$$\begin{array} {c}
 { \beta \text { - galactosidase activity } } \
\begin{array} { | c | c | c | } 
\hline { \text { Mutant } } &\
 & \begin{array} { l } 
\text { Glucose present; } \
\text { lactose absent }
\end{array} & \begin{array} { l } 
\text { Lactose present; } \
\text { glucose absent }
\end{array} \
\hline \text { I } & 0 & 0 \
\hline \text { II } & + + + & + + + \
\hline \text { III } & 0 & + + + \
\hline \text { IV } & + + + & 0 \
\hline
\end{array}\end{array}$$

Accepted Answer

A)  Mutant I has an operator region that no longer binds repressor. 
B)  Mutant II has a repressor that no longer binds to the operator. 
C)  Mutant III has a promoter site that no longer binds RNA polymerase. 
D)  Mutant IV has a mutation in the $\beta$-galactosidase gene, rendering its gene product inactive. 
A)  Mutant I has an operator region that no longer binds repressor. 
B)  Mutant II has a repressor that no longer binds to the operator. 
C)  Mutant III has a promoter site that no longer binds RNA polymerase. 
D)  Mutant IV has a mutation in the $\beta$-galactosidase gene, rendering its gene product inactive.

Question 17

The lac operon is under negative control by a repressor that is sensitive to lactose concentrations and is also under positive control by the activator protein _______, which is sensitive to glucose concentrations.

Accepted Answer

The answer of The lac operon is under negative control...

Question 18

Two bacterial populations were prepared in a laboratory. Population A expresses the wild-type regulator protein that controls the transcription of gene X. Population B contains a mutation in the gene for this regulator protein and does not express any form of the protein. Which statement provides a possible hypothesis to explain the gene X expression data shown in the table below? $$\begin{array} { | c | c | c | } 
\hline \text { Bacterial population } & \begin{array} { c } 
\text { Regulator protein } \
\text { expression }
\end{array} & \text { Gene } X \text { expression } \
\hline \text { A } & \text { wild-type } & + + + \
\hline \text { B } & \text { none } & 0 \
\hline
\end{array}$$

Accepted Answer

A)  The regulator protein is an activator that is required for stimulating RNA polymerase to transcribe gene X. 
B)  The regulator protein binds to RNA polymerase to prevent it from binding to the promoter site and transcribing gene X. 
C)  The regulator protein is a repressor that binds to an operator site and blocks RNA polymerase from carrying out transcription. 
D)  The regulator protein is an inhibitor that binds to RNA polymerase and prevents it from binding to the promoter site. 
A)  The regulator protein is an activator that is required for stimulating RNA polymerase to transcribe gene X. 
B)  The regulator protein binds to RNA polymerase to prevent it from binding to the promoter site and transcribing gene X. 
C)  The regulator protein is a repressor that binds to an operator site and blocks RNA polymerase from carrying out transcription. 
D)  The regulator protein is an inhibitor that binds to RNA polymerase and prevents it from binding to the promoter site.

Question 19

_______ use the energy of ATP hydrolysis to alter and restructure nucleosomes.

Accepted Answer

Chromatin

Question 20

E. coli regulates the biosynthesis of the amino acid tryptophan through the tryptophan (trp) operon. When tryptophan levels are high inside the cell, tryptophan binds to a regulatory protein, which then binds to the operator site of the operon. This shuts down transcription of the genes encoding enzymes needed for tryptophan biosynthesis, and tryptophan biosynthesis is halted. The trp operon is an example of

Accepted Answer

A)  positive control because binding of a repressor blocks transcription. 
B)  negative control because binding of a repressor blocks transcription. 
C)  positive control because binding of an activator stimulates transcription. 
D)  negative control because binding of an activator stimulates transcription. 
A)  positive control because binding of a repressor blocks transcription. 
B)  negative control because binding of a repressor blocks transcription. 
C)  positive control because binding of an activator stimulates transcription. 
D)  negative control because binding of an activator stimulates transcription.

One way that a promoter differs from an enhancer is that it

A reporter gene is used to

A researcher hypothesizes that expression of a particular gene is under positive transcriptional control. What evidence would support his hypothesis?

In eukaryotic cells, genes with methylated DNA tend to be more active than unmethylated genes.

A researcher has several transcription factors in purified form as well as a DNA fragment in purified form. He suspects the DNA fragment binds to one of the transcription factors. He can use the _______ technique to determine which transcription factor the DNA fragment binds to.

Which rationale best describes the ability of an enhancer to mediate transcription from very distant sites?

lncRNAs act as scaffolds to support proteins that regulate

Some chromatin remodeling factors use energy from ATP hydrolysis to slide histones along a chromosome. Explain how this type of activity can regulate gene expression.

Which statement about epigenetic changes is true?

What are three ways in which an enhancer's function differs from that of a promoter?

Prokaryotes are single-celled organisms and do not undergo differentiation. Why is it important that these cells have gene regulatory mechanisms, some of which repress transcription and others that stimulate transcription?

Which is not a type of histone modification used for controlling gene expression?

The lac operon is under negative control by a repressor that is sensitive to lactose concentrations and is also under positive control by the activator protein _______, which is sensitive to glucose concentrations.

_______ use the energy of ATP hydrolysis to alter and restructure nucleosomes.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

Exam 9: Transcriptional Regulation and Epigenetics

One way that a promoter differs from an enhancer is that it

A reporter gene is used to

A researcher hypothesizes that expression of a particular gene is under positive transcriptional control. What evidence would support his hypothesis?

In eukaryotic cells, genes with methylated DNA tend to be more active than unmethylated genes.

A researcher has several transcription factors in purified form as well as a DNA fragment in purified form. He suspects the DNA fragment binds to one of the transcription factors. He can use the _______ technique to determine which transcription factor the DNA fragment binds to.

Which rationale best describes the ability of an enhancer to mediate transcription from very distant sites?

lncRNAs act as scaffolds to support proteins that regulate

Some chromatin remodeling factors use energy from ATP hydrolysis to slide histones along a chromosome. Explain how this type of activity can regulate gene expression.

Which statement about epigenetic changes is true?

What are three ways in which an enhancer's function differs from that of a promoter?

Prokaryotes are single-celled organisms and do not undergo differentiation. Why is it important that these cells have gene regulatory mechanisms, some of which repress transcription and others that stimulate transcription?

Which is not a type of histone modification used for controlling gene expression?

The lac operon is under negative control by a repressor that is sensitive to lactose concentrations and is also under positive control by the activator protein _______, which is sensitive to glucose concentrations.

_______ use the energy of ATP hydrolysis to alter and restructure nucleosomes.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters