Question

What's a gastrula?

Answer 1

Gastrula

1. It is an early multicellular embryo stage, composed of two or more germinal layers of cells from which the various organs later derive.
2. The gastrula develops from the hollow, single-layered ball of cells called a blastula which itself is the product of the repeated cell division, or cleavage, of a fertilized egg.
3. Gastrula is the embryo at the stage succeeding blastula when it is a cup-shaped structure composed of three layers of cells.
4. Gastrulation commences in the third week wherein the embryo begins to differentiate into three germinal layers.