Corpus luteum in pregnancy has a long life. However if fertilisation does not take place, it remains active only for 10-12 days. Explain.

Explanation

Ans. After fertilization, the developing zygote is implanted on endometrium of uterus which initiates a neural signal. It is conducted to hypothalamus to sustain the LH secretion. This maintains the corpus luteum and continued secretion of progesterone during the gestation period. But when no fertilization occurs, no such neural signal is indicated, then corpus luteum starts degenerating and has a short life span of only 10-12 days.