👉 In biology, cleavage is a process by which cells in an organism separate from each other and form two or more distinct cells. It is often used to describe the separation of sperm into two or more sperms during fertilization. Sperm are released from the testes of males and swim through the vas deferens to reach the seminal vesicles, where they attach to a zona pellucida, which is a specialized layer of tissue that surrounds the corpus luteum. Once in the