Question 1

Which of the following best describes the function of an operon in bacterial transcription regulation?

Accepted Answer

A group of genes that are regulated together and transcribed as a single mRNA.

Question 2

In the lac operon, what is the role of the repressor protein?

Accepted Answer

It binds to the operator to prevent RNA polymerase from transcribing the genes.

Question 3

Which of the following equations correctly represents the process of transcription?

Accepted Answer

$$DNA \rightarrow mRNA$$

Question 4

A mutation in the promoter region of a bacterial operon would most likely result in:

Accepted Answer

Reduced or abolished transcription of the operon's genes.

Question 5

Which of the following best explains why the trp operon is considered a repressible operon?

Accepted Answer

It is usually active but can be turned off when tryptophan is present.

Question 6

Which of the following is NOT a component of a typical bacterial operon?

Accepted Answer

Enhancer

Question 7

In eukaryotic gene expression, what is the primary function of transcription factors?

Accepted Answer

They bind to specific DNA sequences to regulate the transcription of genes.

Question 8

Which of the following best describes the difference between euchromatin and heterochromatin?

Accepted Answer

Euchromatin is less condensed and transcriptionally active, while heterochromatin is highly condensed and transcriptionally inactive.

Question 9

Which of the following scenarios best illustrates the role of noncoding RNAs in gene expression?

Accepted Answer

A microRNA binds to an mRNA molecule, preventing its translation into protein.

Question 10

Which of the following best describes the process of negative control in bacterial gene regulation?

Accepted Answer

A repressor protein binds to the operator to block transcription.

Question 11

A scientist wants to detect the presence of a specific mRNA in a cell. Which of the following sequences should she design for her nucleic acid probe?

Accepted Answer

A sequence that is complementary to the target mRNA.

Question 12

Which of the following is a likely outcome if a mutation prevents the binding of the lac repressor to the operator?

Accepted Answer

The lac operon genes would be transcribed continuously, even in the absence of lactose.

Question 13

Which of the following best explains the dual regulation of the lac operon by both lactose and glucose?

Accepted Answer

Lactose induces the operon by inactivating the repressor, while low glucose increases cAMP, activating CAP to enhance transcription.

Question 14

Which of the following is a direct result of histone acetylation in eukaryotic cells?

Accepted Answer

Increased transcription due to a more relaxed chromatin structure.

Question 15

Which of the following best describes the function of an enhancer in eukaryotic gene regulation?

Accepted Answer

A DNA sequence that increases the rate of transcription when bound by specific proteins.

Regulation of Gene Expression – Study Guide (Chapter 15)

Study Guide - Practice Questions