During the course of development, cells in various regions of embryo become variable in morphology and eventually perform diverse functions. This process is known as

In which of the following the placenta forms an important structure in development

The extra structure that provides nutrition to the embryo is

Assertion : During fertilization only head of spermatozoa enters egg.

Reason : If several spermatozoa hit the egg at same time, all can enter the egg.

Placenta produced which hormone

By the end of about .......... weeks, the body is covered with fine hair.