Investigators discovered two eukaryotic regulatory proteins that control expression of the same gene. Their findings are summarized in the table below. Which hypothesis is most consistent with these findings? \[\begin{array} { | c | c | c | c | c | } \hline & \begin{array} { c } \text { Binding } \\ \text { specificity of } \\ \text { protein to DNA } \end{array} & \begin{array} { c } \text { Number of } \\ \text { domains in } \\ \text { protein } \end{array} & \begin{array} { c } \text { Protein } \\ \text { molecular } \\ \text { weight } \end{array} & \begin{array} { c } \text { Effect on } \\ \text { transcription } \end{array} \\ \hline \begin{array} { c } \text { Regulatory } \\ \text { protein I } \end{array} & \text { CACGTG } & 2 & 130 \mathrm { kDa } & \text { Stimulates } \\ \hline \begin{array} { c } \text { Regulatory } \\ \text { protein II } \end{array} & \text { CACGTG } & 1 & 70 \mathrm { kDa } & \text { Represses } \\ \hline \end{array}\]

A) Both regulatory proteins block the binding of activators to DNA. B) Both regulatory proteins affect transcription by binding to mediator proteins. C) Regulatory protein I blocks the binding of activators to DNA, whereas regulatory protein II affects transcription by binding to mediator proteins. D) Regulatory protein I affects transcription by binding to mediator proteins, whereas regulatory protein II blocks the binding of activators to DNA. A) Both regulatory proteins block the binding of activators to DNA. B) Both regulatory proteins affect transcription by binding to mediator proteins. C) Regulatory protein I blocks the binding of activators to DNA, whereas regulatory protein II affects transcription by binding to mediator proteins. D) Regulatory protein I affects transcription by binding to mediator proteins, whereas regulatory protein II blocks the binding of activators to DNA.

The results from several gene transfer assays carried out to locate regulatory DNA sequences are shown in the table below. Three different transcription factors were used in the assay as probes. Luciferase was used as the reporter protein, and production of light is noted with + signs. No production of light is noted with a 0. The results indicate that _______ of the five DNA sequences tested may be have some sort of gene regulatory role. \[\begin{array} { | c | c | c | c | c | c | } \hline \begin{array} { c } \text { Transcription } \\ \text { factor } \end{array} & \begin{array} { c } \text { DNA } \\ \text { sequence I } \end{array} & \begin{array} { c } \text { DNA } \\ \text { sequence II } \end{array} & \begin{array} { c } \text { DNA } \\ \text { sequence III } \end{array} & \begin{array} { c } \text { DNA } \\ \text { sequence IV } \end{array} & \begin{array} { c } \text { DNA } \\ \text { sequence V } \end{array} \\ \hline \mathrm { X } & + + + & 0 & 0 & 0 & 0 \\ \hline \mathrm { Y } & 0 & 0 & + + + & 0 & 0 \\ \hline \mathrm { Z } & 0 & 0 & + + + & 0 & + + + \\ \hline \end{array}\]

The answer of The results from several gene transfer assays...

Exam 9: Transcriptional Regulation and Epigenetics

A mutation in the i gene of the lac operon produces a repressor that retains its DNA binding function but loses its ability to bind to lactose. Will bacteria with this mutant repressor be able to survive in a medium containing lactose as the only carbon source? Explain.

(Essay)

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Question 21

Many transcriptional activators are composed of two or more independent _______, each with its own separate function.

(Multiple Choice)

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Question 22

Which enzyme would be most useful in an experimental investigation of the effects of chromatin remodeling factors on a particular section of chromatin?

(Multiple Choice)

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Question 23

Chromatin remodeling factors are responsible for shuffling and rearranging DNA sequences in chromatin to make them either more or less accessible for transcription.

(True/False)

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Question 24

You know that there is a protein in a particular cell line that binds within the first 200 bp of a gene's promoter to activate its transcription. You have another cell line in which the same gene is not expressed, and you suspect that this is due to the lack of binding to this protein. How could electrophoretic-mobility shift assays (EMSA) help test your hypothesis?

(Essay)

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Question 25

Suppose a transcriptional activator binds to a specific DNA site near a promoter region. Which is a protein that is then stimulated to form a functional transcription complex at this site?

(Multiple Choice)

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Question 26

Describe two general mechanisms of transcriptional inhibition by eukaryotic repressors.

(Essay)

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Question 27

Describe an electrophoretic mobility shift assay.

(Essay)

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Question 28

Long noncoding RNAs (lncRNAs) are often described as having a scaffolding role in the regulation of gene expression. Explain what that means.

(Essay)

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Question 29

DNA is able to form _______, which enable transcription factors at enhancers to interact with the transcription initiation complexes at promoters.

(Short Answer)

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Question 30

Chromosomes are organized into multiple loop structures that maintain specificity of enhancers for their cognate genes by the proteins _ and _.

(Short Answer)

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Question 31

In Drosophila, genes encoding heat shock proteins are normally not expressed by are arrested at early transcription phase. However, if these organisms are exposed to sudden bursts of heat, transcription elongation is stimulated and the heat shock proteins are expressed. Which of the following is a possible mechanism that could account for this heat shock effect?

(Multiple Choice)

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Question 32

If E. coli is in an environment that is rich in lactose, a metabolite of lactose binds to

(Multiple Choice)

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Question 33

Describe whether the control mechanism of the lac operon is positive or negative, and why.

(Essay)

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Question 34

Low concentrations of lactose in a bacterial cell lead to a _______ binding to the operator site of the lac operon and blocking transcription.

(Short Answer)

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Question 35

Some types of cancer are able to progress because certain normally active genes are repressed. An anticancer drug was developed to counteract this by functioning as a histone deacetylase inhibitor. Such an agent will _ and thus _ the expression of genes.

(Multiple Choice)

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Question 36

Investigators discovered two eukaryotic regulatory proteins that control expression of the same gene. Their findings are summarized in the table below. Which hypothesis is most consistent with these findings? Binding specificity of protein to DNA Number of domains in protein Protein molecular weight Effect on transcription Regulatory protein I CACGTG 2 130 Stimulates Regulatory protein II CACGTG 1 70 Represses

(Multiple Choice)

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Question 37

Regulation of the lac operon by lactose involves a(n) _ that inhibits transcription, while regulation by glucose involves a(n) _ that stimulates transcription.

(Multiple Choice)

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Question 38

How are methylated sites in DNA maintained through multiple cycles of DNA replication during development?

(Multiple Choice)

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Question 39

The results from several gene transfer assays carried out to locate regulatory DNA sequences are shown in the table below. Three different transcription factors were used in the assay as probes. Luciferase was used as the reporter protein, and production of light is noted with + signs. No production of light is noted with a 0. The results indicate that _______ of the five DNA sequences tested may be have some sort of gene regulatory role. Transcription factor DNA sequence I DNA sequence II DNA sequence III DNA sequence IV DNA sequence V +++ 0 0 0 0 0 0 +++ 0 0 0 0 +++ 0 +++

(Short Answer)

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Question 40

A mutation in the i gene of the lac operon produces a repressor that retains its DNA binding function but loses its ability to bind to lactose. Will bacteria with this mutant repressor be able to survive in a medium containing lactose as the only carbon source? Explain.

Many transcriptional activators are composed of two or more independent _______, each with its own separate function.

Which enzyme would be most useful in an experimental investigation of the effects of chromatin remodeling factors on a particular section of chromatin?

Chromatin remodeling factors are responsible for shuffling and rearranging DNA sequences in chromatin to make them either more or less accessible for transcription.

Suppose a transcriptional activator binds to a specific DNA site near a promoter region. Which is a protein that is then stimulated to form a functional transcription complex at this site?

Describe two general mechanisms of transcriptional inhibition by eukaryotic repressors.

Describe an electrophoretic mobility shift assay.

Long noncoding RNAs (lncRNAs) are often described as having a scaffolding role in the regulation of gene expression. Explain what that means.

DNA is able to form _______, which enable transcription factors at enhancers to interact with the transcription initiation complexes at promoters.

Chromosomes are organized into multiple loop structures that maintain specificity of enhancers for their cognate genes by the proteins _ and _.

If E. coli is in an environment that is rich in lactose, a metabolite of lactose binds to

Describe whether the control mechanism of the lac operon is positive or negative, and why.

Low concentrations of lactose in a bacterial cell lead to a _______ binding to the operator site of the lac operon and blocking transcription.

Some types of cancer are able to progress because certain normally active genes are repressed. An anticancer drug was developed to counteract this by functioning as a histone deacetylase inhibitor. Such an agent will _ and thus _ the expression of genes.

Regulation of the lac operon by lactose involves a(n) _ that inhibits transcription, while regulation by glucose involves a(n) _ that stimulates transcription.

How are methylated sites in DNA maintained through multiple cycles of DNA replication during development?

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

A mutation in the i gene of the lac operon produces a repressor that retains its DNA binding function but loses its ability to bind to lactose. Will bacteria with this mutant repressor be able to survive in a medium containing lactose as the only carbon source? Explain.

Many transcriptional activators are composed of two or more independent _______, each with its own separate function.

Which enzyme would be most useful in an experimental investigation of the effects of chromatin remodeling factors on a particular section of chromatin?

Chromatin remodeling factors are responsible for shuffling and rearranging DNA sequences in chromatin to make them either more or less accessible for transcription.

Suppose a transcriptional activator binds to a specific DNA site near a promoter region. Which is a protein that is then stimulated to form a functional transcription complex at this site?

Describe two general mechanisms of transcriptional inhibition by eukaryotic repressors.

Describe an electrophoretic mobility shift assay.

Long noncoding RNAs (lncRNAs) are often described as having a scaffolding role in the regulation of gene expression. Explain what that means.

DNA is able to form _______, which enable transcription factors at enhancers to interact with the transcription initiation complexes at promoters.

Chromosomes are organized into multiple loop structures that maintain specificity of enhancers for their cognate genes by the proteins _______ and _______.

If E. coli is in an environment that is rich in lactose, a metabolite of lactose binds to

Describe whether the control mechanism of the lac operon is positive or negative, and why.

Low concentrations of lactose in a bacterial cell lead to a _______ binding to the operator site of the lac operon and blocking transcription.

Some types of cancer are able to progress because certain normally active genes are repressed. An anticancer drug was developed to counteract this by functioning as a histone deacetylase inhibitor. Such an agent will _______ and thus _______ the expression of genes.

Regulation of the lac operon by lactose involves a(n) _______ that inhibits transcription, while regulation by glucose involves a(n) _______ that stimulates transcription.

How are methylated sites in DNA maintained through multiple cycles of DNA replication during development?

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

Chromosomes are organized into multiple loop structures that maintain specificity of enhancers for their cognate genes by the proteins _ and _.

Some types of cancer are able to progress because certain normally active genes are repressed. An anticancer drug was developed to counteract this by functioning as a histone deacetylase inhibitor. Such an agent will _ and thus _ the expression of genes.

Regulation of the lac operon by lactose involves a(n) _ that inhibits transcription, while regulation by glucose involves a(n) _ that stimulates transcription.