Estrogen is secreted by

The process of gametogenesis is the formation of which of the following?

Which of the following labelled parts produces energy for the movement of the tail that facilitates sperm motility essential for fertilisation?

$A$ : The number of male gametes produced is several times more than the number of female gametes produced.
$R$ : This compensates for the loss of male gametes during movement.

$GnRH$ stimulates the release of two hormones from the anterior lobe of the pituitary gland.

Arrange the stages of human spermatogenesis in the correct sequence.