EVERYDAY SCIENCE

Detailed explanation-1: -Cleavage. After fertilization, the development of a multicellular organism proceeds by a process called cleavage, a series of mitotic divisions whereby the enormous volume of egg cytoplasm is divided into numerous smaller, nucleated cells. These cleavage-stage cells are called blastomeres.

Detailed explanation-2: -In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres are an essential part of blastula formation, and blastocyst formation in mammals.

Detailed explanation-3: -Cleavage is a period after fertilization, when a 1-cell embryo starts developing into a multicellular organism. It consists of a series of mitotic divisions, which divide the large volume of a fertilized egg into numerous smaller, nucleated cells-blastomeres.

Detailed explanation-4: -Following are the stages of the formation of the blastocyst: The zygote encased in the zona pellucida divides in such a way that the entire process progresses through 2-celled, 4-celled, 8-celled and 16-celled stages. The cells during the cleavage stage are known as blastomeres.

Detailed explanation-5: –In holoblastic cleavage, the zygote is completely divided into two blastomeres. It is also known as total or entire cleavage.