Epigenetic changes are those which do not involve alterations in the DNA sequence. These are caused due to interaction of the genome with the environment.
When are alterations epigenetic?
Epigenetic modifications or tags include DNA methylation and histone modification.
These changes alter DNA accessibility and chromatin structure thus regulating gene expression.
These are the reversible, heritable changes which do not change your DNA sequence, but they can change how your body reads a DNA sequence.
These are necessary for the normal development of organisms.
Stable, long-term epigenetic modifications involve DNA methylation.
Flexible, short-term changes involve histone modifications, such as methylation and acetylation.