Fertilization: The fusion of a sperm with the egg leads to fertilization and the formation of an embryo that attaches to the endometrial lining of the uterus.
Cleavage:
After fertilization, the cells get divided into the early stages of the embryo.
It consists of a series of mitotic divisions.
This process divides the large volume of a fertilized egg into numerous smaller nucleated cells called blastomeres.
The cluster of cells is of similar size as the zygote.