During menstruation the level of progesterone in blood is
Low
High
Normal
Very high
Ovulation does not occur during pregnancy in the human female because
Ripe ova are shed by ovaries into
The main function of mammalian corpus luteum is to produce
What are the changes in the oogonia during the transition of a primary follicle to Graafian follicle ?
Changes in $GnRH$ pulse frequency in femail is controlled by circulating levels of