The process of conversion of non-motile spermatids into motile spermatozoa is called:

In spermatogenesis, at the end of the first meiotic division . . . . . . are formed.

Arrange in the correct sequence the structures formed during spermatogenesis:
$(a)$ Spermatogonia
$(b)$ Secondary spermatocyte
$(c)$ Primary spermatocyte
$(d)$ Spermatid

Name the cells which provide nourishment to the spermatogonia.

When is the second polar body extruded from the oocyte nucleus?

In which of the following organisms is a microlecithal egg (egg with a very small amount of stored food) found?