Question

Which one is initiated by secretion of trophoblast?

• A. Blastulation
• B. Implantation
• C. Cleavage
• D. Gastrulation

Answer 1

The correct option is B Implantation

The blastomeres in the blastocyst are arranged into an outer layer called trophoblast and an inner group of cells attached to it known as inner cell mass which gets attached to the endometrium and the inner cell mass gets differentiated into an embryo. After attachment, the uterine cells divide rapidly and covers the blastocyst and it is embedded in the uterus. Therefore a signal or secretion is given by trophoblast initiate implantation which leads to pregnancy.

So the correct option is 'Implantation'.