Which of the following is an accessory reproductive gland in male mammals?

How many testicular lobules are present in each testis?

If for some reason the $vas deferens$ in the human reproductive system becomes blocked, the reproductive cells will not be able to be transported from:

......... performs a dual function as a primary sex organ as well as an endocrine gland.

In which of the following organisms do the testes descend into the scrotum during the breeding season but move back into the abdominal cavity during the non-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.