Question 1

Which of the following best describes the main difference between genetics and epigenetics?

Accepted Answer

Genetics involves changes in DNA sequence, while epigenetics involves changes in gene expression without altering the DNA sequence.

Question 2

Which molecular mechanism is most directly associated with gene silencing at CpG islands in mammalian promoters?

Accepted Answer

DNA methylation

Question 3

In the honey bee, what is the primary epigenetic factor that determines whether a larva develops into a queen or a worker?

Accepted Answer

The type of nourishment (royal jelly vs. worker jelly) received during early development

Question 4

Which enzyme is responsible for maintaining existing DNA methylation patterns during cell division?

Accepted Answer

DNMT1

Question 5

A gene is silenced in a tumor due to hypermethylation of its promoter. Which gene is most likely affected in this scenario?

Accepted Answer

A tumor suppressor gene

Question 6

Which of the following is NOT a characteristic of epigenetic modifications?

Accepted Answer

They always involve changes in the DNA sequence.

Question 7

Which of the following best explains why identical twins can develop different diseases later in life despite having the same DNA sequence?

Accepted Answer

Epigenetic modifications diverge due to different environmental exposures.

Question 8

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

Accepted Answer

Increased gene expression

Question 9

Which of the following is a function of non-coding RNAs in epigenetic regulation?

Accepted Answer

They participate in chromatin remodeling and gene silencing.

Question 10

Which of the following best describes the role of chromatin remodelers?

Accepted Answer

They use ATP to reposition or eject nucleosomes, altering DNA accessibility.

Question 11

A child inherits a disease allele from their mother, but the disease is only expressed if the allele is inherited from the father. What is this phenomenon called?

Accepted Answer

Genomic imprinting

Question 12

Which of the following is true about X chromosome inactivation in females?

Accepted Answer

One X chromosome is randomly inactivated in each somatic cell, forming a Barr body.

Question 13

Which of the following is a key player in X chromosome inactivation?

Accepted Answer

Xist long non-coding RNA

Question 14

Which of the following best describes the parental conflict hypothesis in genomic imprinting?

Accepted Answer

The father promotes fetal growth, while the mother limits it to preserve her own health and future offspring.

Question 15

Which of the following is an example of transgenerational epigenetic inheritance?

Accepted Answer

A methylation pattern at the agouti locus in mice affecting coat color and health in multiple generations

Question 16

Which of the following best explains why Beckwith-Wiedemann syndrome (BWS) can result from assisted reproductive technologies (ART)?

Accepted Answer

Sub-optimal embryo culture conditions can disrupt the maintenance of mono-allelic expression of imprinted genes.

Question 17

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

Accepted Answer

Silencing of gene expression

Question 18

Which of the following best describes the function of TET enzymes in epigenetic regulation?

Accepted Answer

They oxidize 5-methylcytosine to initiate active DNA demethylation.

Question 19

Which of the following is a real-world application of epigenetic clocks?

Accepted Answer

Estimating the biological age of animals based on DNA methylation patterns

Question 20

Which of the following best explains why epigenetic modifications are considered reversible?

Accepted Answer

Enzymes such as demethylases and deacetylases can remove epigenetic tags.

Epigenetic Regulation in Gene Expression: Mechanisms and Examples

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