Epigenetics: An Overview for Medical Students

Question 1

Which of the following is a defining characteristic of DNA methylation?

Accepted Answer

It can alter chromatin structure.

Answer

It always leads to gene activation.

Answer

It is only found in embryonic stem cells.

Answer

It is an irreversible process.

Question 2

Which process is LEAST directly involved in epigenetic regulation?

Accepted Answer

RNA interference

Answer

DNA methylation

Answer

Histone modification

Answer

Transposable element silencing

Question 3

Which of the following is not a mechanism of epigenetic regulation?

Accepted Answer

RNA interference

Answer

DNA methylation

Answer

Histone acetylation

Answer

MicroRNA

Question 4

Which of the following is not a type of epigenetic modification that regulates gene expression?

Accepted Answer

MicroRNA interference

Answer

DNA methylation

Answer

Histone acetylation

Answer

Phosphorylation of histones

Question 5

Within the context of mammalian cells, where is the majority of DNA methylation found?

Accepted Answer

CpG islands

Answer

Enhancers

Answer

Promoters

Answer

Introns

Question 6

Which of the following is a consequence of histone acetylation?

Accepted Answer

Increased gene expression

Answer

Decreased gene expression

Answer

Heterochromatin formation

Answer

DNA replication

Question 7

What is the primary function of DNA methyltransferase enzymes?

Accepted Answer

To add methyl groups to DNA

Answer

To remove methyl groups from DNA

Answer

To acetylate histones

Answer

To deacetylate histones

Question 8

How can histone modifications be used in gene therapy?

Accepted Answer

By modifying the accessibility of DNA to transcription factors

Answer

By altering the stability of DNA

Answer

By promoting DNA replication

Answer

By repairing damaged DNA

Question 9

Which of the following techniques is primarily used to study DNA methylation patterns?

Accepted Answer

Bisulfite sequencing

Answer

ChIP-seq

Answer

RNA-seq

Answer

Microarrays

Question 10

Which cellular process is impacted by epigenetic regulation?

Accepted Answer

Cell differentiation

Answer

Cell division

Answer

DNA replication

Answer

Protein synthesis

Question 11

Which of the following is NOT a mechanism of epigenetic regulation?

Accepted Answer

Gene mutations

Answer

DNA methylation

Answer

Histone modifications

Answer

RNA interference

Question 12

DNA methylation is typically associated with:

Accepted Answer

Silencing of gene expression

Answer

Activation of gene expression

Answer

Alteration of protein structure

Answer

Modification of RNA molecules

Question 13

Histone acetylation is commonly associated with:

Accepted Answer

Relaxed chromatin and gene activation

Answer

Condensed chromatin and gene silencing

Answer

Enhanced DNA repair

Answer

Increased RNA stability

Question 14

Epigenetic marks can be inherited:

Accepted Answer

Through both the maternal and paternal lineages

Answer

Only through the paternal lineage

Answer

Only through the maternal lineage

Answer

Not at all

Question 15

Which of the following techniques is commonly used to study DNA methylation patterns?

Accepted Answer

Bisulfite sequencing

Answer

Chromatin immunoprecipitation

Answer

microarrays

Answer

RNA sequencing

Question 16

Epigenetics is a rapidly advancing field of research.

Accepted Answer

True

Answer

False

Question 17

In cellular reprogramming, DNA demethylation plays a crucial role. Explain its significance in resetting cell identity.

Accepted Answer

DNA demethylation erases existing epigenetic marks, enabling cells to adopt a new identity.

Answer

DNA demethylation destabilizes the genome.

Answer

DNA demethylation promotes cell specialization.

Question 18

Which of the following is NOT a type of histone modification associated with gene activation?

Accepted Answer

Ubiquitination of lysine residues, which targets histones for degradation

Answer

Acetylation of lysine residues, which neutralizes the positive charge of histones

Answer

Methylation of lysine residues, which creates a binding site for proteins that can promote transcription

Answer

Phosphorylation of serine residues, which leads to a conformational change that exposes DNA

Question 19

Which enzyme is responsible for establishing DNA methylation patterns during embryonic development?

Accepted Answer

DNMT3a and DNMT3b

Answer

DNMT1

Answer

HDAC1

Answer

HAT1

Question 20

The term 'epigenetics' was coined by:

Accepted Answer

C.H. Waddington, a developmental biologist who proposed the concept of epigenetics

Answer

Francis Crick, the co-discoverer of the structure of DNA

Answer

James Watson, the co-discoverer of the structure of DNA

Answer

Rosalind Franklin, the scientist who captured the first X-ray diffraction image of DNA

Question 21

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

Accepted Answer

They permanently alter the DNA sequence.

Answer

They can be influenced by environmental factors.

Answer

They can be passed down through generations.

Answer

They can regulate gene expression.

Question 22

DNA methylation typically occurs at which base within the DNA sequence?

Accepted Answer

Cytosine

Answer

Thymine

Answer

Adenine

Answer

Guanine

Question 23

Which histone modification is typically associated with increased gene expression?

Accepted Answer

Histone acetylation

Answer

Histone deacetylation

Answer

Histone methylation at lysine 27

Answer

Histone methylation at lysine 9

Question 24

A patient has a rare genetic disorder affecting DNA methyltransferase activity. What is a potential consequence of this disorder?

Accepted Answer

Abnormal gene expression patterns, potentially leading to developmental problems or disease.

Answer

Increased DNA stability and reduced risk of mutations.

Answer

Enhanced immune response.

Question 25

Which of the following environmental factors has been linked to epigenetic changes and health outcomes?

Accepted Answer

Dietary intake

Answer

Eye color

Answer

Blood type

Answer

Height

Question 26

Which epigenetic mechanism is primarily responsible for regulating X chromosome inactivation in female mammals?

Accepted Answer

DNA methylation

Answer

Histone phosphorylation

Answer

Histone acetylation

Question 27

Why is studying epigenetic modifications important in the context of cancer development?

Accepted Answer

Epigenetic changes can contribute to the silencing of tumor suppressor genes and the activation of oncogenes.

Answer

Epigenetic changes are only relevant for inherited forms of cancer.

Answer

Epigenetic modifications play no role in cancer development.

Question 28

Which of the following is a potential therapeutic strategy targeting epigenetic modifications?

Accepted Answer

Developing drugs that inhibit DNA methyltransferases.

Answer

Gene therapy to replace defective genes.

Answer

Antibiotics to target bacterial infections.

Question 29

A researcher studying the effects of stress on epigenetic modifications in humans finds that prolonged exposure to stress is associated with increased methylation of specific genes involved in immune regulation. What is a plausible interpretation of this finding?

Accepted Answer

Chronic stress might lead to suppression of immune function through epigenetic mechanisms.

Answer

Stress has no influence on epigenetic modifications.

Answer

Increased methylation of immune-related genes enhances immune response.