Question 1:

What are the chemical modifications that can occur on DNA molecules to regulate gene expression?

Explanation: C) Methylation is a chemical modification that can occur on DNA molecules to regulate gene expression. Methylation typically involves the addition of a methyl group to cytosine residues and can influence gene silencing.

Question 2:

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

Explanation: D) DNA methylation is an example of an epigenetic modification. It involves the addition of a methyl group to DNA and can lead to changes in gene expression patterns without altering the DNA sequence itself.

Question 3:

What is the role of histone acetylation in gene expression?

Explanation: C) Histone acetylation plays a role in gene activation. Acetylation of histone proteins neutralizes their positive charge, leading to a more open chromatin structure and increased accessibility of the DNA, facilitating gene expression.

Question 4:

What is the function of microRNAs (miRNAs) in gene regulation?

Explanation: D) MicroRNAs (miRNAs) function in post-transcriptional regulation. They can bind to complementary sequences in mRNA molecules, leading to mRNA degradation or inhibition of translation, thereby controlling gene expression.

Question 5:

What is the term for the modification of histones that promotes a compacted chromatin structure and gene silencing?

Explanation: A) Methylation of histones promotes a compacted chromatin structure and gene silencing. Methylation can lead to the recruitment of proteins that maintain a repressive chromatin state, inhibiting gene expression.