During coitus,the human male ejaculates about ...... number of sperms.

Who discovered the human sperm?

Oogonia arise from the endoderm of the . . . . . . .

Which of the following undergoes spermiogenesis?

The schematic representation of spermatogenesis is given below. How many chromosomes do $P$,$Q$,and $R$ contain?
$P$ (Spermatogonia) $\rightarrow$ $Q$ (Primary Spermatocyte) $\rightarrow$ $R$ (Spermatid)

Telolecithal eggs have