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 question is an example of epigenetic change. Epigenetic changes refer to alterations in gene expression that do not involve changes in the DNA sequence of the gene. In this case, the rats' genes did not change, but the chemicals that control their gene expression did change as a result of their environment. This suggests that environmental factors can have a significant impact on gene expression and the traits that develop as a result. The other answer choices (B, C, and D) do not accurately describe the phenomenon observed.

In an Experiment, It Was Found That Newborn Rats Who