Which of the following cells secrete testicular hormones called androgens and form endocrine part of the testis?

The Graafian follicle ruptures to release _________ from the ovary by the process called ovulation.

$A$ : Development is the emergence of a multicellular organism from a single group of cells.
$R$ : Development involves growth, differentiation and morphogenesis.

From where spermatogenesis starts ?

After implantation, finger-like projections on the trophoblast are called $…A….$ which are surrounded by  $…B..$ and maternal blood. Here $A$ and $B$ refers to