Question

Describe the blastocyst and explain what happens to the inner and outer cells.

Answer 1

The blastocyst is a structure formed in the early development of mammals. It possesses an inner cell mass (ICM) which subsequently forms the embryo. The outer layer of the blastocyst consists of cells collectively called the trophoblast.The trophoblast gives rise to the placenta.

Answer 2

A fertilized egg by the fifth or sixth day is called a blastocyst - a cell ball that divides rapidly.

• It is formed during the early development stages of mammals. Formed after five days of fertilization it contains about 70-100 cells.
• It consists of the trophoblast, the inner cell mass, and the blastocoel a fluid-filled cavity.
• The outer layer of cells of the blastocyst is called the trophoblast. This is the layer that is responsible for providing nourishment to the embryo and it also develops into a major part of the placenta later.
• The inner cell mass is the part of the blastocyst that later develops into the embryo.