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.

Question

Quizplus · Accepted Answer

The phenomenon described in the scenario is epigenetic change, which refers to changes in the expression of genes without alterations to the underlying genetic code. In this case, the rats' genes did not change, but their behavior and stress-response did due to changes in the chemicals that control gene expression. Allele variation, recessive gene mutation, and dominant gene mutation all refer to specific types of genetic changes, which are not relevant to the scenario described.

In an Experiment It Was Found That Newborn Rats Who