Question

Given below are the steps which occur when an egg is not fertilised.
Arrange them in order.
A) Menstruation occurs.
B) Endometrium degenerates.
C) Progestrone production stops.
D) Corpus luteum degenerates into corpus albicans.

• A. D -> C -> B -> A
• B. A -> C -> D -> B
• C. A -> D -> C -> B
• D. A -> B -> C -> D

Answer 1

The correct option is A D -> C -> B -> A

If the egg is not fertilised after ovulation, corpus luteum starts degenerating. Corpus luteum produces progestrone. Hence, progestrone production stops. Progestrone is responsible for the maintenance of endometrium. When progestrone levels go low, endometrium starts degenerating. This leads to the shredding of egg along with endometrium and blood. This is called menstruation.