What is a Primary Difference Between the Estrous and Menstrual

Question

What is a primary difference between the estrous and menstrual cycles?
A) The endometrium shed by the uterus during the estrous cycle is reabsorbed with no extensive fluid flow out of the body, whereas the shed endometrium of menstrual cycles is excreted from the body.
B) Copulation normally occurs across the estrous cycle, whereas in menstrual cycles copulation only occurs during the period surrounding ovulation.
C) Season and climate have less pronounced effects on estrous cycles than they do on menstrual cycles.
D) Behavioural changes during estrous cycles are much less apparent than those of menstrual cycles.

Accepted Answer

The primary difference between the estrous and menstrual cycles is the way the endometrium shed by the uterus is disposed of. In the estrous cycle, the shed endometrium is reabsorbed by the uterus with no extensive fluid flow out of the body. On the other hand, in menstrual cycles, the shed endometrium is excreted from the body with extensive fluid flow during menstruation.