The blastula and gastrula are two distinct stages of the early embryonic development of animals. Though they are both involved in the formation of the embryo, they differ in their structure and function.
The blastula is a hollow, spherical structure made up of a single layer of cells known as the blastoderm. This layer surrounds a central cavity, called the blastocoel. The blastocoel is filled with liquid and acts as a protective cushion for the cells of the blastoderm.
During the blastula stage, cells are dividing rapidly, forming a hollow sphere that is known as a blastula. The cells of the blastula are totipotent, meaning that they have the ability to differentiate into any cell type, forming the basis of the embryo.
The gastrula is the next stage of development in the embryo. During the gastrula stage, the blastula begins to undergo changes and the cells begin to differentiate. Cells on the outside of the blastula begin to move inward, forming a layer of cells known as the endoderm. Meanwhile, cells on the inner surface of the blastula form the ectoderm. The blastocoel then collapses, forming the archenteron, which is the first cavity of the gut.
The blastula and gastrula are both responsible for the formation of the embryo, but they differ in their structure and function. The blastula is a hollow, spherical structure made up of a single layer of cells, while the gastrula is an inner cavity formed by the collapse of the blastocoel and the differentiation of the cells. Additionally, the cells of the blastula are totipotent, while the cells of the gastrula are committed to a particular cell lineage.
The blastula and gastrula are essential stages in the development of the embryo, and their differences are integral to the formation of the organs and structures of the body. Without the blastula and gastrula, the embryo would not be able to develop properly.
Blastula v/s Gastrula
| S.No. | Blastula | Gastrula |
| 1. | The blastula is formed due to the cleavage of the zygote | Gastrula is formed due to the movements and rearrangement of cells |
| 2. | Blastula has a small or no cavity | Gastrula has a large cavity enclosed in the endoderm |
| 3. | In blastula, there is no germinal layers are formed | In gastrula, germinal layers called ectoderm and mesoderm are formed |
