Question 1

Which of the following best explains why a brain cell and a liver cell in the same individual can have different functions, even though they contain the same DNA sequence?

Accepted Answer

Brain cells and liver cells express different genes due to epigenetic modifications.

Question 2

Which of the following epigenetic modifications is most likely to turn a gene OFF?

Accepted Answer

Addition of methyl groups to DNA

Question 3

A scientist observes that a gene is highly active in skin cells but inactive in muscle cells. Which of the following is most likely true about the chromatin structure of this gene in muscle cells?

Accepted Answer

The DNA is condensed and has many methyl groups attached.

Question 4

Which of the following nutrients is directly involved in donating methyl groups for DNA methylation?

Accepted Answer

Choline

Question 5

In a cancerous cell, which of the following patterns would you most likely observe?

Accepted Answer

Tumor-suppressor genes with more methyl tags than normal

Question 6

Which of the following best describes the role of regulatory proteins in epigenetic gene control?

Accepted Answer

They recruit enzymes that add or remove epigenetic tags on DNA or histones.

Question 7

A mouse pup raised by a high-nurturing mother is more likely to become a relaxed adult. What is the epigenetic mechanism underlying this behavioral change?

Accepted Answer

Decreased methylation of the GR gene in the hippocampus

Question 8

Which of the following statements about epigenetic tags is TRUE?

Accepted Answer

Epigenetic tags can be influenced by environmental factors such as diet and stress.

Question 9

Which of the following dietary components has been shown to increase histone acetylation and turn on anti-cancer genes?

Accepted Answer

Sulforaphane

Question 10

If a gene is active, which of the following is most likely TRUE?

Accepted Answer

The DNA is decondensed, with few methyl groups and many acetyl groups.

Question 11

Which of the following best explains why identical twins can become more different from each other as they age?

Accepted Answer

They accumulate different epigenetic tags due to unique life experiences.

Question 12

Which of the following is an example of epigenetic inheritance that would be considered convincing evidence?

Accepted Answer

An epigenetic change observed in the fourth generation after exposure to a toxin.

Question 13

Which of the following best describes genomic imprinting?

Accepted Answer

A process where certain genes retain their epigenetic tags and are expressed in a parent-of-origin-specific manner.

Question 14

A researcher injects a drug that adds methyl tags to the GR gene in a relaxed, high-nurtured rat. What is the most likely outcome?

Accepted Answer

The rat will become more anxious.

Question 15

Which of the following best explains why a queen bee and a worker bee can have different physical characteristics despite being genetically identical?

Accepted Answer

They are exposed to different diets that cause different epigenetic modifications.

Question 16

Which of the following is a direct result of increased histone acetylation?

Accepted Answer

DNA becomes less condensed and gene expression increases.

Question 17

Which of the following best describes the effect of a diet rich in methyl donors (such as choline, folic acid, and vitamin B12) on the agouti gene in mice?

Accepted Answer

It increases methylation of the agouti gene, resulting in thin, healthy mice.

Question 18

Which of the following statements about the reversibility of epigenetic patterns is TRUE?

Accepted Answer

Epigenetic patterns can be reversed by environmental factors such as diet and drugs.

Question 19

Which of the following best describes the role of the HPA axis in the stress response?

Accepted Answer

It releases cortisol, which helps free stored energy and can affect long-term health.

Epigenetics: Mechanisms and Biological Implications

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