Egg which contains very little amount of yolk are called as
Alecithal
Microlecithal
Mesolecithal
Polylecithal
Microlecithal eggs are found in
The allantois has the similar layers as present in the yolk sac. These are
The permeability of the human placenta to macro-molecules is evidenced by the presence of following in foetal blood
Meridional cleavage results in blastomeres numbering
$A$ : If both the ovaries are removed after the first trimester of pregnancy, still there would be normal growth of foetus.
$R$ : After first trimester placenta secretes sufficient progesterone