Human Reproduction

During menopause, the level of estrogen in the blood decreases. Thus, estrogen can no longer inhibit the production of and . Therefore, and (mainly ) are produced after menopause in large quantities and these (mainly ) are excreted out in urine.

Answer (d) At the middle of the cycle

Answer (b) Flagellum

Identical twins (monozygotic twins) are two individuals that develop from a single fertilised egg cell (zygote) by its division into two genetically identical parts. Each part eventually gives rise to a separate individual and these twins are therefore identical in every respect.