In: Biology
Answer: Epigenetics is the study of heritable phynotipic changes that particularly do not involve any changes or alterations in DNA sequence. It refers to any changes that leads to change in activity and expression of any gene, which in turn effects the cellular physiology.
Epigenetic markers are the features that are not directly controlled by the DNA sequence or genetic code. The changes are carried out by methylation of DNA or covalent modification of histone proteins. The changes can also be introduced by other biochemical groups such as methyl, acetyl, ubiquitin, phosphate, poly (ADP) ribose etc. These groups modify the proteins in a particular pattern, for instance, mono-, bi-, tri-methylation at various amino acids and combinations of amino acids, which results in modification of the function of the respective proteins. Now the modified proteins influence the expression of the proteins.