In an experiment, it was found that newborn rats who were genetically predisposed to be skittish, nervous, and high-strung would
develop into calm, exploratory, and stress-resistant adult rats when raised by genetically unrelated, attentive mothers. Although the rats' DNA did not change, the chemicals that controlled their gene expression did change, a phenomenon called: a) epigenetic change. b) allele variation. c) recessive gene mutation. d) dominant gene mutation.
Epigenetic is referred to changes BESIDES the changes in the genetic changes. It means, not related to mutations but to chemical changes such as methylation, acetylation, ubiquitylation, phosphorylation, that can interfere with the genetic expression. Chromatin modification is another way of epigenetic change.
