The solid mass of cells formed at the end of cleavage of a mammalian egg is:

The function of the placenta is to .......

The pattern of cleavage in an egg is determined by which of the following?

Thalidomide is a non-barbiturate sedative drug which was given to pregnant women. Its use was withdrawn in $1961$ because it resulted in phocomelia. This condition illustrates:

The hormone released from the placenta is

The third phase in the development of a mammal is