What term describes a heritable change in gene activity that does not alter the DNA sequence?

An epigenetic change is a heritable change in gene activity that does not alter the DNA sequence.

Epigenetic regulation can involve DNA methylation, chemical modification of histone proteins, and changes in chromatin structure. These mechanisms influence whether cellular machinery can access particular genes, helping cells with the same genome develop into different cell types.

Some epigenetic states persist when a cell divides, allowing patterns of gene activity to be inherited by daughter cells. In mammals, however, much epigenetic information is reset during reproduction, so it is incorrect to assume that every acquired epigenetic mark passes unchanged to offspring.

Epigenetic regulation is different from mutation: a mutation changes the DNA sequence itself, whereas an epigenetic change alters how that sequence is used. The two can interact, because epigenetic states may influence mutation rates and gene expression.