The following series of 10 questions refer to the accompanying diagram of the uterine-ovarian-hormonal cycle.
-What triggers the events is steps 21 and 22?
A) rise in estrogen
B) fall in progesterone
C) pregnancy
D) ovulation
E) none of the above

Question

The following series of 10 questions refer to the accompanying diagram of the uterine-ovarian-hormonal cycle. 
-What triggers the events is steps 21 and 22?
A) rise in estrogen 
B) fall in progesterone 
C) pregnancy 
D) ovulation 
E) none of the above

Quizplus · Accepted Answer

A fall in progesterone triggers the events in steps 21 and 22, which are typically associated with the onset of menstruation.

The Following Series of 10 Questions Refer to the Accompanying