Question 1

Which of the following best describes the role of general transcription factors in eukaryotic gene regulation?

Accepted Answer

They are required for the binding of RNA polymerase to the core promoter and progression to the elongation stage.

Question 2

A regulatory protein that increases the rate of transcription by binding to a specific DNA sequence is called:

Accepted Answer

An activator

Question 3

Which DNA sequence does a repressor protein typically bind to in order to decrease transcription?

Accepted Answer

Silencer

Question 4

What is the effect of DNA methylation on gene expression?

Accepted Answer

It prevents the binding of activator proteins and silences gene expression.

Question 5

Which of the following is a mechanism by which regulatory transcription factor function can be modulated?

Accepted Answer

Binding of a small effector molecule

Question 6

In the regulation of iron assimilation, what happens to ferritin mRNA translation when iron levels are high?

Accepted Answer

Iron binds to IRP, preventing IRP from binding to the IRE, allowing translation.

Question 7

Which of the following histone modifications is associated with increased transcriptional activity?

Accepted Answer

Histone acetylation

Question 8

What is the primary function of insulator DNA sequences in eukaryotic gene regulation?

Accepted Answer

To block the effects of neighboring enhancers and prevent inappropriate gene activation.

Question 9

A patient with Rubinstein-Taybi syndrome is found to have a mutation in the gene encoding CBP. What is the most likely molecular consequence?

Accepted Answer

Defective histone acetylation leading to altered chromatin structure and gene expression.

Question 10

Which of the following best explains why nerve and muscle cells look so different despite having the same DNA content?

Accepted Answer

Differences in gene regulation rather than differences in DNA content.

Question 11

Which process uses the energy of ATP hydrolysis to reposition nucleosomes and alter chromatin structure?

Accepted Answer

ATP-dependent chromatin remodeling

Question 12

What is the effect of an activator protein binding to an enhancer sequence?

Accepted Answer

Up-regulation of transcription, potentially increasing transcription rates by 10- to 1,000-fold.

Question 13

Which of the following equations correctly represents the phosphorylation of CREB protein by protein kinase A?

Accepted Answer

$$CREB + ATP \rightarrow CREB{-}P + ADP$$

Question 14

Which of the following is TRUE regarding the nucleosome-free region (NFR) in protein-encoding genes?

Accepted Answer

It is typically found at the beginning and end of many genes, facilitating transcription initiation and termination.

Question 15

In the regulation of transferrin receptor mRNA, what happens when iron levels are high?

Accepted Answer

Iron binds to IRP, causing IRP to dissociate from the IRE, leading to mRNA degradation.

Question 16

Which of the following is NOT a way that regulatory transcription factor function can be modulated?

Accepted Answer

DNA replication

Question 17

Which of the following statements about chromatin conformation is correct?

Accepted Answer

Closed conformation (heterochromatin) is tightly packed and transcriptionally inactive.

Question 18

A mutation that prevents histone acetylation would most likely result in which of the following?

Accepted Answer

Reduced transcription due to more tightly bound DNA and closed chromatin.

Question 19

Which of the following best describes combinatorial control in gene regulation?

Accepted Answer

Multiple regulatory proteins and modifications work together to regulate a single gene.

Question 20

Which enzyme is responsible for adding methyl groups to cytosine residues in DNA?

Accepted Answer

DNA methyltransferase

Eukaryotic Gene Regulation: Mechanisms and Molecular Control

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