Which of the following statements are correct regarding female reproductive cycle?

(A) In non-primate mammals cyclical changes during reproduction are called oestrous cycle.

(B) First menstrual cycle begins at puberty and is called menopause.

(C) Lack of menstruation may be indicative of pregnancy.

(D) Cyclic menstruation extends between menarche and menopause.

Choose the most appropriate answer from the options given below.

A, C and D are correct. B is incorrect.

A. In non-primate mammals, cyclical changes during reproduction are called the oestrous cycle.

B. The first menstrual cycle begins at puberty in females. The fi rest menstruation is called menarche.
Menopause refers to the permanent cessation of menstrual cycles, around the age of 50 years.

C. Lack of menstruation may be indicative of pregnancy. During pregnancy, menstruation does not occur because the fertilised egg implants in the uterus and hormonal changes prevent the shedding of the uterine lining.

D. Cyclic menstruation extends between menarche (the first occurrence of menstruation) and menopause (the
permanent cessation of menstrual cycles). This statement is correct.