Question 1

An electrophoresis assay used to identify the sequences of DNA to which specific regulatory proteins bind is called

Accepted Answer

A)  an electrophoretic-mobility shift assay. 
B)  DNA affinity chromatography. 
C)  Western blotting. 
D)  Southern blotting. 
A)  an electrophoretic-mobility shift assay. 
B)  DNA affinity chromatography. 
C)  Western blotting. 
D)  Southern blotting. A

Question 2

Suppose that gene X is induced in E. coli cells when they are treated with high levels of ethanol. A mutation in region 1 in the upstream region of gene X results in high-level expression under basal conditions, and a mutation in region 2 results in an uninducible gene. What would you expect from a strain in which both regions 1 and 2 are mutated?

Accepted Answer

Because a mutation in region 1 causes high-level expression even in the absence of ethanol, region 1 must bind a transcriptional repressor and regulation of gene X must occur by relief of repression. Since a mutation in region 2 blocks inducibility of the gene, region 2 must bind a transcriptional activator: In the absence of an activator, the repressor becomes irrelevant, and the gene is inactive, regardless of conditions. Mutations in both regions 1 and 2 would have the same effect as the single mutation in region 2, because in the absence of a bound transcriptional activator, the repressor is irrelevant, and the gene is inactive regardless of the presence or absence of ethanol.

Question 3

Some corepressors bind to transcription factors at transcription initiation sites and recruit deacetylases that remove acetyl groups from histone lysine groups, leading to condensation of chromatin and repression of transcription.

Accepted Answer

A) True 
 B)False  True

Question 4

A reporter gene is one that

Accepted Answer

A)  causes other genes to be expressed. 
B)  can produce an easily detectable product when expressed under the control of a regulatory sequence to which it has been ligated and cloned. 
C)  is always on. 
D)  is turned on by the products of other genes. 
A)  causes other genes to be expressed. 
B)  can produce an easily detectable product when expressed under the control of a regulatory sequence to which it has been ligated and cloned. 
C)  is always on. 
D)  is turned on by the products of other genes.

Question 5

A eukaryotic regulatory protein controls expression of a gene. Some data regarding this protein are listed in the table below. Which hypothesis about the mechanism of this protein can be ruled out? $$\begin{array} { | c | c | c | c | c | } 
\hline & \begin{array} { c } 
\text { Binding } \
\text { specificity of } \
\text { protein to DNA }
\end{array} & \begin{array} { c } 
\text { Number of } \
\text { domains in } \
\text { protein }
\end{array} & \begin{array} { c } 
\text { Domain } \
\text { functions }
\end{array} & \begin{array} { c } 
\text { Effect on } \
\text { transcription }
\end{array} \
\hline \begin{array} { c } 
\text { Regulatory } \
\text { protein X }
\end{array} & \text { GGAACT } & 1 & \begin{array} { c } 
\text { DNA binding } \
\text { domain }
\end{array} & \text { Inhibits } \
\hline
\end{array}$$

Accepted Answer

A)  This protein blocks an activating transcription factor from binding to the promoter. 
B)  This protein prevents RNA polymerase from binding to the promoter. 
C)  This protein competes with a transcription activator for binding to an enhancer. 
D)  This protein binds to Mediator proteins in the transcription initiation complex. 
A)  This protein blocks an activating transcription factor from binding to the promoter. 
B)  This protein prevents RNA polymerase from binding to the promoter. 
C)  This protein competes with a transcription activator for binding to an enhancer. 
D)  This protein binds to Mediator proteins in the transcription initiation complex.

Question 6

You have a cell line that contains a gene that regulates cell cycle re-entry. It is normally repressed by a transcriptional repressor that has two functional domains: a DNA binding domain and a repressor domain that inhibits the activity of RNA polymerase. What would likely happen if a protein encoding only the DNA binding domain became dramatically overexpressed in these cells?

Accepted Answer

Most likely, the repression would be rem

Question 7

The lac operon in E. coli is regulated by lactose, which

Accepted Answer

A)  activates an activator of transcription. 
B)  inactivates an activator of transcription. 
C)  activates a repressor of transcription. 
D)  inactivates a repressor of transcription. 
A)  activates an activator of transcription. 
B)  inactivates an activator of transcription. 
C)  activates a repressor of transcription. 
D)  inactivates a repressor of transcription.

Question 8

How are chromatin remodeling factors similar to and different from histone acetyltransferases and deacetylases?

Accepted Answer

While both types of factors disrupt hist

Question 9

Eukaryotic gene regulation is facilitated by

Accepted Answer

A)  acetylation of histones. 
B)  phosphorylation of histones. 
C)  methylation of histones. 
D)  All of the above 
A)  acetylation of histones. 
B)  phosphorylation of histones. 
C)  methylation of histones. 
D)  All of the above

Question 10

The molecule providing the scaffolding in the figure below to allow multiple chromatin modifications is a(n) _______.

Accepted Answer

long nonco

Question 11

Eukaryotic transcriptional activators have activation domains that interact with

Accepted Answer

A)  DNA binding domains. 
B)  enhancers and promoters. 
C)  mediator proteins and transcription factors. 
D)  histones. 
A)  DNA binding domains. 
B)  enhancers and promoters. 
C)  mediator proteins and transcription factors. 
D)  histones.

Question 12

Methylation of histones results in

Accepted Answer

A)  activation of transcription. 
B)  repression of transcription. 
C)  activation or repression of transcription, depending on the site. 
D)  neither activation nor repression of transcription, only condensation of chromatin. 
A)  activation of transcription. 
B)  repression of transcription. 
C)  activation or repression of transcription, depending on the site. 
D)  neither activation nor repression of transcription, only condensation of chromatin.

Question 13

Genomic imprinting is thought to result from

Accepted Answer

A)  acetylation of histones. 
B)  methylation of cytosine residues in DNA. 
C)  binding of transcription factors to promoters. 
D)  binding of Xist RNA to genes. 
A)  acetylation of histones. 
B)  methylation of cytosine residues in DNA. 
C)  binding of transcription factors to promoters. 
D)  binding of Xist RNA to genes.

Question 14

What two different mechanisms do transcription factors use to regulate transcription of eukaryotic genes?

Accepted Answer

Transcription factors regulate transcrip

Question 15

Which of the following experimental approaches is least likely to be used to identify transcription factor binding sites on DNA?

Accepted Answer

A)  Electrophoretic-mobility shift assay 
B)  DNA-affinity chromatography 
C)  A reporter gene assay 
D)  Chromatin immunoprecipitation
Learning Objective: Summarize the experimental approaches used to study the binding of transcription factors to DNA. 
A)  Electrophoretic-mobility shift assay 
B)  DNA-affinity chromatography 
C)  A reporter gene assay 
D)  Chromatin immunoprecipitation
Learning Objective: Summarize the experimental approaches used to study the binding of transcription factors to DNA.

Question 16

Which information would be helpful in determining whether a particular bacterial gene is under positive or negative transcriptional control?

Accepted Answer

A)  The gene is part of an operon. 
B)  The gene is regulated by the level of a metabolite inside the cell. 
C)  The gene codes for an enzyme that has an important metabolic purpose. 
D)  The gene is not transcribed when a repressor protein binds to DNA. 
A)  The gene is part of an operon. 
B)  The gene is regulated by the level of a metabolite inside the cell. 
C)  The gene codes for an enzyme that has an important metabolic purpose. 
D)  The gene is not transcribed when a repressor protein binds to DNA.

Question 17

Methylation of certain lysine residues in histones leads to gene silencing, whereas methylation of other lysine residues in the same histones leads to transcriptional activation. How can methylation lead to these two different outcomes?

Accepted Answer

Methylation changes which regulatory pro

Question 18

Cancer cells repress some genes that are expressed in normal cells. Suppose you wanted to design two drugs to treat cancer cells. Which activities would you want your drugs to have?

Accepted Answer

A)  DNA methylase activity and histone acetyltransferase activity 
B)  DNA demethylase activity and histone acetyltransferase activity 
C)  DNA methylase activity and histone deacetylase activity 
D)  DNA demethylase activity and histone deacetylase activity 
A)  DNA methylase activity and histone acetyltransferase activity 
B)  DNA demethylase activity and histone acetyltransferase activity 
C)  DNA methylase activity and histone deacetylase activity 
D)  DNA demethylase activity and histone deacetylase activity

Question 19

Which statement concerning lncRNAs is true?

Accepted Answer

A)  lncRNAs are extracellular signals that stimulate activation of specific genes. 
B)  lncRNAs catalyze the chemical modification of histones. 
C)  lncRNAs function in both activation and repression of gene expression. 
D)  lncRNAs are formed once RNA polymerase becomes active after having been paused. 
A)  lncRNAs are extracellular signals that stimulate activation of specific genes. 
B)  lncRNAs catalyze the chemical modification of histones. 
C)  lncRNAs function in both activation and repression of gene expression. 
D)  lncRNAs are formed once RNA polymerase becomes active after having been paused.

Question 20

An investigation was carried out to identify different sections of mammalian DNA as either promoters or enhancers of gene Y transcription. Wild-type mammalian cells functioned normally, while mutant cells lacked the ability to produce functional cohesion protein. Based on the data in the table below, which conclusion is valid? $$\begin{array} { | c | c | c | } 
\hline \text { Cells } & \text { Regulatory sequence } & \text { Expression of gene } \boldsymbol { Y } \
\hline { \text { Wild-type } } & \mathrm { A } & + + + \
& \mathrm { B } & + + + \
\hline { \text { Mutant } } & \mathrm { A } & + + + \
& \mathrm { B } & 0 \
\hline
\end{array}$$

Accepted Answer

A)  Both A and B are enhancers. 
B)  Both A and B are promoters. 
C)  A is an enhancer, and B is a promoter. 
D)  A is a promoter, and B is an enhancer. 
A)  Both A and B are enhancers. 
B)  Both A and B are promoters. 
C)  A is an enhancer, and B is a promoter. 
D)  A is a promoter, and B is an enhancer.

An electrophoresis assay used to identify the sequences of DNA to which specific regulatory proteins bind is called

Some corepressors bind to transcription factors at transcription initiation sites and recruit deacetylases that remove acetyl groups from histone lysine groups, leading to condensation of chromatin and repression of transcription.

A reporter gene is one that

The lac operon in E. coli is regulated by lactose, which

How are chromatin remodeling factors similar to and different from histone acetyltransferases and deacetylases?

Eukaryotic gene regulation is facilitated by

The molecule providing the scaffolding in the figure below to allow multiple chromatin modifications is a(n) _______.

Eukaryotic transcriptional activators have activation domains that interact with

Methylation of histones results in

Genomic imprinting is thought to result from

What two different mechanisms do transcription factors use to regulate transcription of eukaryotic genes?

Which of the following experimental approaches is least likely to be used to identify transcription factor binding sites on DNA?

Which information would be helpful in determining whether a particular bacterial gene is under positive or negative transcriptional control?

Methylation of certain lysine residues in histones leads to gene silencing, whereas methylation of other lysine residues in the same histones leads to transcriptional activation. How can methylation lead to these two different outcomes?

Cancer cells repress some genes that are expressed in normal cells. Suppose you wanted to design two drugs to treat cancer cells. Which activities would you want your drugs to have?

Which statement concerning lncRNAs is true?

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

An electrophoresis assay used to identify the sequences of DNA to which specific regulatory proteins bind is called

Some corepressors bind to transcription factors at transcription initiation sites and recruit deacetylases that remove acetyl groups from histone lysine groups, leading to condensation of chromatin and repression of transcription.

A reporter gene is one that

The lac operon in E. coli is regulated by lactose, which

How are chromatin remodeling factors similar to and different from histone acetyltransferases and deacetylases?

Eukaryotic gene regulation is facilitated by

The molecule providing the scaffolding in the figure below to allow multiple chromatin modifications is a(n) _______.

Eukaryotic transcriptional activators have activation domains that interact with

Methylation of histones results in

Genomic imprinting is thought to result from

What two different mechanisms do transcription factors use to regulate transcription of eukaryotic genes?

Which of the following experimental approaches is least likely to be used to identify transcription factor binding sites on DNA?

Which information would be helpful in determining whether a particular bacterial gene is under positive or negative transcriptional control?

Methylation of certain lysine residues in histones leads to gene silencing, whereas methylation of other lysine residues in the same histones leads to transcriptional activation. How can methylation lead to these two different outcomes?

Cancer cells repress some genes that are expressed in normal cells. Suppose you wanted to design two drugs to treat cancer cells. Which activities would you want your drugs to have?

Which statement concerning lncRNAs is true?

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