LIFE SCIENCE

Detailed explanation-1: -In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote.

Detailed explanation-2: -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.

Detailed explanation-3: -Cleavage of Zygote It is holoblastic, dividing the zygote fully into blastomeres or daughter cells. After fertilisation, the first cleavage occurs about 24 to 30 hours later. It creates two blastomeres by longitudinally dividing the zygote (one mildly larger than the other).