Question 1

Which of the following best explains how histone acetylation affects gene expression in eukaryotic cells?

Accepted Answer

Histone acetylation loosens chromatin structure, making DNA more accessible for transcription.

Question 2

A researcher treats breast cancer cells with AZA, a DNA methylation inhibitor, and observes decreased cell survival. What is the most likely explanation for this result?

Accepted Answer

Inhibiting DNA methylation increases expression of tumor suppressor genes, reducing cancer cell survival.

Question 3

Based on the glioblastoma survival graph, what is the effect of MGMT promoter methylation on patient response to temozolomide?

Accepted Answer

MGMT promoter methylation silences MGMT gene expression, improving temozolomide effectiveness.

Question 4

Which of the following is a direct result of DNA methylation at gene promoter regions?

Accepted Answer

Decreased gene expression due to reduced transcription factor binding.

Question 5

A mutation prevents the switch from fetal (Form F) to adult (Form A) splicing of a heart muscle gene after birth. What is the most likely physiological consequence?

Accepted Answer

The heart will continue to grow rapidly, potentially leading to dysfunction.

Question 6

Which process is illustrated by the addition of a methyl group to cytosine in DNA, as shown in the third image?

Accepted Answer

DNA methylation

Question 7

If a synthetic miRNA inhibitor is applied to immune cells, what is the most likely outcome for the target gene's protein product?

Accepted Answer

Protein levels will increase due to decreased mRNA degradation.

Question 8

Which of the following best describes the role of ubiquitin in post-translational regulation?

Accepted Answer

Ubiquitin tags proteins for degradation by the proteasome.

Question 9

A scientist treats cells with a histone acetyltransferase (HAT) activator. What is the most likely effect on gene expression?

Accepted Answer

Chromatin becomes looser, increasing gene expression.

Question 10

Which of the following is a key difference between epigenetic inheritance and DNA mutations?

Accepted Answer

Epigenetic inheritance involves reversible modifications to DNA or histones, while mutations are permanent changes to the DNA sequence.

Question 11

In the maternal nutrition experiment, why did researchers feed all offspring a normal diet after weaning?

Accepted Answer

To ensure that any observed effects were due to prenatal and early postnatal nutrition, not later diet.

Question 12

Which of the following best describes the effect of treating offspring from low-protein mothers with a HAT activator?

Accepted Answer

Hnf4a expression would increase due to chromatin decondensation.

Question 13

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

Accepted Answer

They help position RNA polymerase II at the promoter to initiate transcription.

Question 14

What is the role of repressors in gene regulation?

Accepted Answer

Repressors bind to promoter or silencer regions to block transcription.

Question 15

Which of the following best explains why cells evolved multiple layers of gene regulation?

Accepted Answer

To allow precise, flexible, and rapid control of gene expression in response to internal and external signals.

Question 16

Which regulatory mechanism allows a single gene to produce multiple protein variants?

Accepted Answer

Alternative RNA splicing

Question 17

If both AZA (DNA methylation inhibitor) and TSA (histone deacetylase inhibitor) are used together on breast cancer cells, what is the expected effect on cell survival compared to using either drug alone?

Accepted Answer

Cell survival will be lower than with either drug alone.

Question 18

Which of the following best describes the function of microRNAs (miRNAs) in gene regulation?

Accepted Answer

miRNAs bind to mRNA and promote degradation or inhibit translation.

Question 19

Which of the following is a likely long-term health consequence for offspring of mothers fed a low-protein diet, based on the Hnf4a gene study?

Accepted Answer

Impaired glucose metabolism and increased risk of diabetes.

Regulation of Gene Expression: Study Guide and Case Studies

Guida di studio - Domande di pratica

Study guide - Flashcard