Final answer:
DNA methylation is a type of epigenetic change that occurs during mitosis and provides a mechanism for epigenetic change. It involves adding a methyl group to the DNA molecule and can lead to gene silencing or altered patterns of gene expression.
Step-by-step explanation:
Epigenetics is the study of the regulation of gene expression through chemical, non-mutational changes in DNA structure. DNA methylation is a type of epigenetic change that involves adding a methyl group to the DNA molecule. This modification can occur during mitosis and provides a mechanism for epigenetic change. DNA methylation can lead to gene silencing, where the methylated genes are usually inactive or have altered patterns of gene expression.