Blastula (Gr, Blastos - Embryo)

Blastula is an important stage of embryonic development that occurs after fertilization of the egg. During this stage, the fertilized egg is fragmented into many smaller cells, which form a spherical body surrounded by a single layer of cells and filled with fluid.

The name "blastula" comes from the Greek word "blastos", which means "embryo". This stage of development is of fundamental importance in biology, since it is at this stage that the active development of the embryo begins.

The formation of a blastula begins with the formation of blastomeres - small cells formed as a result of mitotic division of a fertilized egg. The blastomeres are arranged in a circle surrounding a cavity that is filled with fluid. This cavity is called the blastocoel.

The layer of cells surrounding the blastocoel is called the blastoderm. The walls of the blastula are usually thin, but strong enough to maintain the shape of the embryo. Blastodermal cells produce fluid that fills the blastocoel and protect the embryo from the external environment.

During the development of the embryo, the blastula plays a key role. During the further development of the embryo, the blastula turns into a gastrula, which in turn gives rise to all organs and tissues of the body.

Thus, the blastula is an important stage in the development of the embryo, which is the first step towards the formation of a complex organization of the body. Without this stage of development, life on Earth would be impossible.