Epigenetics and Gene Expression Concepts

Epigenetics refers to changes that affect gene expression without altering what?

• The protein sequence

• The DNA sequence

• The cell's organelles

• The organism's physical traits

What is the primary effect of methylation on DNA?

• It causes DNA to replicate faster.

• It prevents transcription factors from binding to DNA.

• It changes the sequence of DNA bases.

• It helps repair damaged DNA.

What are histones primarily responsible for in relation to DNA?

• Carrying genetic information to ribosomes.

• Unwinding the DNA double helix during replication.

• Packaging DNA by acting as spools.

• Synthesizing new DNA strands.

What happens to DNA when acetyl groups are attached to histones (acetylation)?

• The DNA becomes more tightly wrapped, blocking transcription.

• The DNA sequence is permanently altered.

• The DNA loosens, allowing transcription factors to access it.

• The DNA is broken down and recycled.

How does a mother rat's licking and grooming behavior affect her offspring's stress response?

• It causes a mutation in the GR gene, making offspring more stressed.

• It adds epigenetic marks to the GR gene, blocking its transcription and leading to more stressed behavior.

• It removes epigenetic marks from the GR gene, allowing its transcription and leading to less stressed behavior.

• It directly changes the DNA sequence of the GR gene, altering the stress response.

Two mice have the same DNA, but one is brown and average size, while the other is yellow and obese. What is the most likely reason for this difference?

• The brown mouse has a mutated Agouti gene.

• The yellow mouse has an active Agouti gene due to epigenetic factors.

• The brown mouse has a different set of genes than the yellow mouse.

• The yellow mouse's diet caused a permanent change in its DNA.

A pregnant mouse is fed a diet high in methyl groups. How might this diet affect the Agouti gene in her offspring?

• It will cause the offspring to have a mutated Agouti gene.

• It will increase the expression of the Agouti gene in the offspring, making them yellow and obese.

• It will decrease the expression of the Agouti gene in the offspring, making them brown and average size.

• It will have no effect on the offspring's Agouti gene expression.

Human body cells like eye cells and stomach cells contain the same DNA. Why do they perform different functions?

• They have different sets of genes.

• They actively transcribe different genes based on their cell type.

• Eye cells have mutations that stomach cells do not.

• Stomach cells have extra DNA that eye cells lack.