Question 1

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

Accepted Answer

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

Question 2

Which molecular mechanism is most directly responsible for silencing gene expression at CpG islands in mammalian promoters?

Accepted Answer

DNA methylation

Question 3

A researcher finds that a tumor suppressor gene is not expressed in a cancer cell line, even though the DNA sequence is normal. Which epigenetic mechanism is most likely responsible?

Accepted Answer

Hypermethylation of the gene's promoter region

Question 4

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

Accepted Answer

DNMT1

Question 5

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

Accepted Answer

Diet, specifically the consumption of royal jelly

Question 6

Which of the following is NOT a typical function of non-coding RNAs in epigenetic regulation?

Accepted Answer

Directly encoding proteins

Question 7

Which of the following best explains why identical twins can develop different diseases as adults, despite having the same DNA sequence?

Accepted Answer

Accumulation of different epigenetic modifications over time

Question 8

Which of the following histone modifications is generally associated with increased gene activity?

Accepted Answer

Histone acetylation

Question 9

A mutation in the gene encoding a histone deacetylase (HDAC) would most likely result in which of the following?

Accepted Answer

Increased gene expression due to hyperacetylation of histones

Question 10

Which of the following best describes the role of chromatin remodelers in gene regulation?

Accepted Answer

They use ATP to reposition or eject nucleosomes, making DNA accessible for transcription.

Question 11

Which of the following is a key feature of genomic imprinting?

Accepted Answer

Monoallelic expression of a gene depending on the parent of origin

Question 12

A child inherits a mutation in a gene that is only expressed from the paternal allele due to imprinting. If the mutation is inherited from the mother, what is the expected outcome?

Accepted Answer

The child will not show the phenotype because the maternal allele is silenced.

Question 13

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

Accepted Answer

Paternal genes promote fetal growth, while maternal genes limit growth to conserve resources.

Question 14

Which syndrome is associated with loss of maternal expression of a gene on chromosome 15q13?

Accepted Answer

Angelman syndrome

Question 15

Which of the following is a real-world example of transgenerational epigenetic inheritance?

Accepted Answer

Maternal diet affecting coat color in offspring via methylation of the agouti gene in mice

Question 16

Which of the following best describes the function of the Imprinted Control Region (ICR) in genomic imprinting?

Accepted Answer

It acts as a cis-acting DNA sequence that regulates parent-of-origin-specific monoallelic expression.

Question 17

Which of the following statements about epigenetic changes during aging is correct?

Accepted Answer

Random errors in epigenetic modifications increase gene expression noise and phenotypic variation between cells.

Question 18

Which of the following is a correct statement about the reversibility of epigenetic modifications?

Accepted Answer

Epigenetic modifications are generally reversible and can be influenced by environmental factors.

Question 19

Which of the following best describes the role of TET enzymes in DNA methylation?

Accepted Answer

They actively oxidize 5-methylcytosine to initiate demethylation.

Question 20

A patient with Beckwith-Wiedemann syndrome (BWS) is found to have biallelic expression of IGF2 and loss of H19 expression. Which epigenetic mechanism is most likely disrupted?

Accepted Answer

Imprinting control region (ICR) methylation

Epigenetic Regulation in Gene Expression: Mechanisms and Examples

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