Lack of menstruation is caused due to

The secretory phase in the human menstrual cycle is also called

Assertion : Corpus luteum degenerates in the absence of fertilization.

Reason : Progesterone level decreases.

The menstrual cycle in normal adult woman is of

Ripe ova are shed by ovaries into

Which one of the following events is correctly matched with the time period in a normal menstrul cycle