$A$: After menopause,the levels of blood gonadotropins rise markedly.
$R$: At the time of menopause,all the ovarian follicles are converted into follicular atresia,and the ovaries do not respond to the gonadotropins.

Some important events in the human female reproductive cycle are given below. Arrange the events in a proper sequence. $A \rightarrow$ secretion of $FSH$,$B \rightarrow$ growth of corpus luteum,$C \rightarrow$ growth of the follicle and oogenesis,$D \rightarrow$ ovulation,$E \rightarrow$ sudden increase in the level of $LH$.

The hormone that maintains the secretory activity of the corpus luteum as well as the increase in the size of the mammary glands is

Differentiate between $(a)$ oestrus and menstrual cycles; $(b)$ ovipary and vivipary. Give an example for each type.

$A$ female of $24$ years age attained puberty at the age of $14$ years. She has two children born by normal delivery. How many polar bodies are formed in her body till date $($each $\text{M.C.}$ is of $30$ days$)$ :-

$A.$ Humans reproduce .....
$B.$ Humans are $\ldots \ldots$
$C.$ Fertilization is .... in humans
$D.$ Male and female gametes are .....
$E.$ Zygote is .....
$F.$ The process of release of ovum from a mature follicle is called .....
$G.$ Ovulation is induced by a hormone called ......
$H.$ The fusion of male and female gametes is called .......
$I.$ Zygote divides to form ... which is implanted in the uterus
$J.$ The structure which provides vascular connection between the foetus and uterus is called ......
Fill in the blanks in the statements $A$ to $J$ above.