Sperms formed from $4$ primary spermatocytes are

Movement of sperm is done by

Gametogenesis is the formation of

$A$ : $LH$ acts on Sertoli cells for release of certain factors required for spermatogenesis.
$R$ : Spermiation occurs directly under influence of $LH$

Which of the following groups of cell in the male gonad, represent haploid cells?

Ejaculation of human male contains about $200 -300$ million sperms, of which for normal fertility ____ $\%$ sperms must have normal shape and size and at least ____$\%$ must show energetic motility.