The tertiary egg membrane is:

Name a cell that is found arrested in the diplotene stage for months or years. Comment in $2-3$ lines on how it completes its cell cycle.

$.....P.....$ undergo meiosis to form sperms. $.....Q.....$ provide nutrition to the germ cells.
Choose the correct option for $P$ and $Q$.
$\quad\quad\quad\quad P \quad\quad\quad Q$

Sertoli cells are found in:

Arrange in the correct sequence the structures formed during spermatogenesis:
$(a)$ Spermatogonia
$(b)$ Secondary spermatocyte
$(c)$ Primary spermatocyte
$(d)$ Spermatid

When is the polar body extruded from the oocyte?