The cavity formed during gastrulation is known as:

The first movement of the fetus and the appearance of hair on the head are usually observed during which month of pregnancy?

The process of cell differentiation begins and ends in which of the following stages?

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 . . . . . . .

Most of the major organ systems in the foetus are formed $:-$

During the fourth and sixth cleavage of the zygote in sea urchin development,what is the fate of the resulting cells?