Question 1:

Which of the following is an epigenetic modification?

Explanation: DNA methylation is an epigenetic modification that 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 2:

Which of the following is an example of a histone modification?

Explanation: Histone acetylation is an example of a histone modification. It involves the addition of acetyl groups to histone proteins, which can relax the chromatin structure and promote gene expression.

Question 3:

How does DNA methylation affect gene expression?

Explanation: DNA methylation generally inhibits gene expression. Methyl groups attached to cytosine residues can attract proteins that bind to DNA and prevent the transcription machinery from accessing the gene, leading to gene silencing.

Question 4:

Which of the following is NOT a histone modification?

Explanation: Replication is not a histone modification. It is a process that involves the copying of DNA during cell division.

Question 5:

How do histone modifications influence gene expression?

Explanation: Histone modifications can alter chromatin structure, making genes more accessible or inaccessible to the transcription machinery. This can regulate gene expression by either promoting or inhibiting transcription.