Ovulation does not occur during pregnancy in the human female because
The follicles are not influenced by the level of progesterone in the blood
The corpus luteum and later the placenta produce large amounts of progesterone
The corpus luteum generates as luteinising hormone is no longer produced
The embryo produces hormones which retard the production of maternal follicle stimulating hormones
Lack of menstruation is caused due to
If after ovulation no pregnancy results, the corpus luteum
Menstrual cycle occurs in
About which day in a normal human menstrual cycle does rapid secretion of $LH$ (popularly called $LH$ surge) normally occurs?
Ripe ova are shed by ovaries into