Question

In terms of DNA repair and gene expression, what is the most common form of chemical modifications to the DNA after DNA synthesis happens?

Answer 1

DNA methylation is the most common chemical modification post-DNA synthesis, generally suppressing transcription and potentially being inherited. DNA repair mechanisms fix mutations and maintain DNA integrity.

Step-by-step explanation:

The most common form of chemical modifications to DNA after DNA synthesis is the addition of methyl groups to the DNA, a process known as methylation. Methylation generally suppresses transcription and these methylation patterns can even be inherited.

Chemical changes can also occur due to the introduction of mutations by chemical mutagens or radiation. Repair mechanisms such as DNA repair pathways like Base Excision Repair, Nucleotide Excision Repair, Mismatch Repair, and others ensure the maintenance of DNA integrity.