It is the structural and functional unit between the developing embryo (foetus) and the maternal body.

Gastrula has a pore which is known as . . . . . .

During pregnancy,the levels of which hormones are increased?

The lens of the eye is derived from which germ layer?

Select the mismatched pair:
$A$. First month of pregnancy - Formation of heart
$B$. Second month of pregnancy - Movement of foetus
$C$. Third month of pregnancy - Formation of most of the major organ systems
$D$. Sixth month of pregnancy - Eye lids separate and eye lashes are formed

The first sign of the growing foetus may be noticed by listening to the heart sound carefully through the stethoscope. The embryo's heart is formed . . . . . . .