How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?

Match the column-$I$ with column-$II$.

Column-$I$	Column-$II$
$(A)$ Leydig cells	$(i)$ Provides nutrition to developing sperm
$(B)$ Sertoli cells	$(ii)$ Secrete mainly progesterone
$(C)$ Corpus luteum	$(iii)$ Secrete inhibin
$(D)$ Developing follicle	$(iv)$ Secrete androgen

In the egg of a bird,the shell and shell membranes are:

What is the period between $12$ and $18$ years of age in a person called?

Choose the correct sequence of events occurring in human reproduction.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Endometrium is necessary for implantation of blastocyst.
Reason $R$: In the absence of fertilization,the corpus luteum degenerates that causes disintegration of endometrium.
In the light of the above statements,choose the correct answer from the options given below: