What is the process of gastrulation?
Gastrulation is a phase in embryonic development during which the single layered blastula develops into a three layered gastrula.
Gastrulation takes place after cleavage.
The cells in the blastula rearrange themselves spatially to form three layers of cells in a process known as gastrulation.
During gastrulation the blastula folds in on itself to form three germ layers :-- the ectoderm, the mesoderm and the endoderm. These give rise to the internal structure of the organism.
The endoderm gives rise to nervous system and epidermis.
The mesoderm gives rise to muscle cells and connective tissues in the body.
Endoderm gives rise to columnar cells found in the digestive system and many internal organs.