The seminiferous tubules of the testis open into the vasa efferentia by:

In which of the following animals do the testes descend into the scrotum only during the breeding season?

Given below is a diagram of the $T.S.$ of a testis. Select the option which gives the correct identification of the function of cells labeled $A, B, C,$ and $D$ from the options given below.
$A$ - cells undergo spermatogenesis to produce spermatozoa.
$B$ - cell responsible for the development of male secondary sexual characters.
$C$ - heads of sperms remain attached to these cells.
$D$ - haploid male gamete.

Accessory glands of the human male reproductive system are:

The enlarged end of the penis is called the ..........

Which gland/structure secretes the male sex hormone?