Question 1:

What are epigenetic modifications?

Explanation: Epigenetic modifications refer to changes in gene expression without altering the DNA sequence itself. These modifications can include DNA methylation, histone modifications, and non-coding RNA molecules that influence gene activity.

Question 2:

What is DNA methylation?

Explanation: DNA methylation involves the addition of methyl groups to cytosine residues in DNA. This modification can regulate gene expression by influencing the accessibility of DNA to transcription factors and other regulatory proteins.

Question 3:

What are histone modifications?

Explanation: Histone modifications are alterations in the structure of nucleosomes, which are complexes of DNA and histone proteins. These modifications include acetylation, methylation, phosphorylation, and others, and they can influence gene expression by changing the accessibility of DNA and recruiting specific proteins to chromatin.

Question 4:

Which of the following is an example of an epigenetic mechanism?

Explanation: X-chromosome inactivation is an example of an epigenetic mechanism. In female mammals, one of the X chromosomes is randomly inactivated in each cell during early development. This ensures dosage compensation between males and females and is an epigenetic modification that leads to the formation of Barr bodies.

Question 5:

What is the role of epigenetic modifications in development?

Explanation: Epigenetic modifications play a crucial role in development by regulating the timing and specificity of gene expression. They control cell differentiation and determine cell fate during embryonic development, ensuring that the right genes are expressed in the right cells at the right time.