Question

.(a) Why does menstruation occur?

(b) What are the functions performed by the testis in human beings. (c) drow a labelled diagram of the longitudinal section of flower.

plz tell me correct answer...... ​

Answer 1

Answer:

1. A period happens because of changes in hormones in the body. Hormones are chemical messengers. The ovaries release the female hormones estrogen and progesterone . These hormones cause the lining of the uterus (or womb) to build up.

2.

Answer 2

Answer:

Menstruation is bleeding from the uterus of human females at an interval of about 28/29 days. Since the ovary releases one egg every month, the uterus also prepares itself every month to receive a fertilized egg. Thus its lining becomes thick and spongy. This would be required for nourishing the embryo if fertilization had taken place. However, in the absence of fertilization, this lining is not needed any longer. So, the lining slowly breaks and comes out through the vagina as blood and mucous. Thus, menstruation occurs to discard the uterine lining and unfertilized ovum in the absence of fertilization.