Which of the Following is a True Statement

Question

Which of the following is a true statement?
A) All mammals have menstrual cycles.
B) The endometrial lining is shed in menstrual cycles but reabsorbed in estrous cycles.
C) Estrous cycles are more frequent than menstrual cycles.
D) Estrous cycles are not controlled by hormones.
E) Ovulation occurs before the endometrium thickens in estrous cycles.

Accepted Answer

The shedding of the endometrial lining occurs in menstrual cycles, while it is reabsorbed in estrous cycles. Therefore, option B is the correct statement. Options A and D are incorrect as not all mammals have menstrual cycles and estrous cycles are controlled by hormones. Option C is not necessarily true as it depends on the species. Option E is also incorrect as ovulation occurs before the endometrium thickens in menstrual cycles, not in estrous cycles.