An experiment found that newborn rats who were genetically predisposed to be calm and stress-resistant grew up to be nervous, high-strung, and easily stressed adult rats when raised by genetically unrelated, inattentive mothers. These results showed that:
A) the rats' DNA changed because of their upbringing.
B) epigenetic changes had changed their brain chemistry and literally reprogrammed their future behavior.
C) severe genetic mutations had taken place from one generation to the next.
D) the rats' DNA was damaged by environmental factors, such as exposure to ultraviolet light, radiation, or chemical toxins.

Question

Quizplus · Accepted Answer

The experiment showed that even though the rats were genetically predisposed to be calm and stress-resistant, their upbringing caused epigenetic changes that altered their brain chemistry and behavior. This suggests that environmental factors can have a significant impact on gene expression and subsequent behavior. There is no evidence to support options A, C, or D.

An Experiment Found That Newborn Rats Who Were Genetically Predisposed