Answer:
Cleavage is a process in which cell is divided into several parts without increasing in size. There are 4 stages of cleavage i. e. 2-cell, 4-cell, 8-cell and 16 cell stages. 2 cell embryo cleavage occurs after 30 hours of fertilization. 4 cell embryo cleavage occurs after 48 hours. 6 cell embryo cleavage occurs on third day of fertilization. 8 cell embryo cleavage occurs on fourth day of fertilization and more than 100 cells are formed.