$A$ : The first sign of growing foetus may be noticed by listening to the heart sound through the stethoscope.
$R$ : By the end of second month of pregnancy, the foetus develops limbs and digits.

Formation of notochord or the central axial chord in vertebrates is known as

The central nervous system develops as a result of

Testosterone is produced (Synthesised) by

Meroblastic cleavage refers to one of the following types of division of eggs