Which of the following is an example of a polyoestrous mammal?

Where does the structural transformation of sperm occur?

Match Column-$I$ with Column-$II$:

Column-$I$	Column-$II$
$(A)$ Mons pubis	$(1)$ Embryo formation
$(B)$ Antrum	$(2)$ Sperm
$(C)$ Trophectoderm	$(3)$ Female external genitalia
$(D)$ Nebenkern	$(4)$ Graafian follicle

Identify the $CORRECT$ match from the Columns $I$,$II$ and $III$.

$I$	$II$	$III$
$1$. Interstitial cells	$a$. Cortex of ovary	$i$. Follicular fluid
$2$. Sertoli cells	$b$. Ovarian follicle	$ii$. Progesterone
$3$. Granulosa cells	$c$. Testis	$iii$. Attachment of sperm bundle
$4$. Cells of corpus luteum	$d$. Seminiferous tubules	$iv$. Testosterone

Given below are the events in human reproduction. Write them in correct sequential order: Insemination,gametogenesis,fertilisation,parturition,gestation,implantation.

Describe the location and function of the following: Placenta and Acrosome.