The cyclic period of sexual activity in non-human female mammals is called

What is the fertile period?

Human female reaches menopause at the age of about (in $years$)

Given below are two statements with respect to the menstrual cycle.
$Statement-I$: The menstrual phase in the menstrual cycle occurs when an ovulated egg is not fertilized and is thus shed out along with the endometrium.
$Statement-II$: The menstrual phase is often referred to as the 'funeral of an unfertilized egg'.
Choose the most appropriate answer from the options given below.

During the menstrual cycle,cyclical changes take place in:

During menstruation,the level of progesterone in the blood is: