The cleavage in the human zygote is.....

In human beings,cleavage of the fertilized egg:

In humans,fertilization is only possible if:

In sexually reproducing multicellular animals,where does the development begin?

$A$ change in the amount of yolk and its distribution in the egg will affect

After implantation,finger-like projections on the trophoblast are called $...A....$ which are surrounded by $...B..$ and maternal blood. Here $A$ and $B$ refers to