The blastula of prototherians is called

Meroblastic cleavage refers to which type of division of egg

Tertiary egg membranes are lacking in mammals with the exception of the

Foetal ejection reflex in human female is induced by

The mother germ cells are transformed into a mature follicle through series of steps. Provide the missing steps in the blank boxes.

$\boxed{{\text{Oogonia}}}$ $\to $ $\boxed{\text{A}}$ $\to $ $\boxed{{\text{Primary follicle}}}$ $\to $ $\boxed{\text{B}}$ $\to $$\boxed{\text{C}}$ $\to $ $\boxed{{\text{Mature or Graafian follicle}}}$

A freshly unfertilized egg of hen contains