Question 1

Which of the following best describes the role of histone acetyl transferases (HATs) in gene expression regulation?

Accepted Answer

HATs add acetyl groups to histones, promoting chromatin decondensation and increased transcription.

Question 2

A mutation causes the loss of a promoter proximal element in a gene. What is the most likely consequence?

Accepted Answer

Transcription will decrease because activators can no longer bind efficiently.

Question 3

Which process is directly responsible for removing introns from a pre-mRNA transcript?

Accepted Answer

Splicing

Question 4

If a cell increases the methylation of cytosine bases in a gene's promoter region, what is the expected effect on gene expression?

Accepted Answer

Gene expression will decrease because methylation recruits proteins that condense chromatin.

Question 5

Which of the following is a post-translational modification that can alter protein activity?

Accepted Answer

Phosphorylation

Question 6

A researcher discovers a protein that binds to an enhancer sequence far upstream of a gene. What is the most likely function of this protein?

Accepted Answer

It acts as an activator, increasing transcription of the gene.

Question 7

Which equation best represents the conversion of ATP to ADP during protein phosphorylation?

Accepted Answer

$$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i}$$

Question 8

Which of the following mechanisms can regulate gene expression at the translational level?

Accepted Answer

Changing the rate at which translation begins on mRNA

Question 9

A point mutation changes the codon AUG (methionine) to UAG in an mRNA transcript. What is the consequence for the resulting protein?

Accepted Answer

Translation will terminate prematurely because UAG is a stop codon.

Question 10

Which of the following best describes the 'Central Dogma' of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 11

Which of the following is a consequence of chromatin condensation?

Accepted Answer

Decreased gene expression due to reduced access to DNA

Question 12

RNA interference (RNAi) can silence gene expression by which mechanism?

Accepted Answer

Degrading complementary mRNA molecules

Question 13

Which of the following is NOT a level at which gene expression can be regulated?

Accepted Answer

Genomic replication

Question 14

A mutation causes the inversion of a DNA segment containing an enhancer. What is the most likely effect?

Accepted Answer

The enhancer may lose its ability to activate transcription if orientation is critical.

Question 15

Which protein complex is responsible for shifting nucleosome positions to expose or cover DNA regulatory sequences?

Accepted Answer

Chromatin remodeling complex

Question 16

Which of the following is a function of general transcription factors?

Accepted Answer

They are required for the initiation of transcription at almost all core promoters.

Question 17

Which of the following scenarios best illustrates post-transcriptional control of gene expression?

Accepted Answer

An mRNA molecule is spliced to remove introns before translation.

Question 18

Which of the following is true about promoter proximal elements?

Accepted Answer

They are DNA sequences near the core promoter that bind activator proteins.

Question 19

Which of the following is a direct effect of adding acetyl groups to histone proteins?

Accepted Answer

Chromatin becomes more open, increasing gene expression.

Question 20

A cell is exposed to a drug that inhibits the activity of kinases. Which process will be directly affected?

Accepted Answer

Phosphorylation of proteins

Regulation of Gene Expression: Transcriptional, Translational, and Post-Translational Control

Study Guide - Practice Questions