In rats, maternal behavior has a lifelong effect on stress responses of their offspring by altering expression of the GR gene. The GR gene is expressed at higher levels in rats who were cared for by attentive mothers. This is an epigenetic effect, that is, the sequence of DNA bases is not changed while gene expression is changed.
A. Describe an epigenetic change that would cause GR gene expression to increase.
C. Explain why there is an increase in gene expression in response to this epigenetic change.