The outer layer of the blastocyst is called:

Cleavage is found in

What is the most likely reason for the absence of regular menstruation in women?

The chemical substance found in the surface layer of cytoplasm of spermatozoa is

Identify the human developmental stage shown below as well as the related right place of its occurrence in a normal pregnant woman,and select the right option for the two,together.

When more than one sperm establish contact and penetrate into the egg,then it is called