Infant rats deprived of their mothers' normal licking had more ________ that block access to the "on" switch for developing the brain's stress hormone receptors.

Question

Quizplus · Accepted Answer

The sentence describes how the lack of normal licking from the mothers led to more "epigenetic molecules" that block access to developing the brain's stress hormone receptors. Therefore, the best choice is D, "epigenetic molecules." None of the other options fit the description provided in the sentence.

Infant Rats Deprived of Their Mothers' Normal Licking Had More