Question

Approximately how many days does human cleavage take?  

Answer 1

In human beings, zygote is formed after fertilization of male and female gametes. After fertilization, zygote undergoes cleavage (repeated mitotic divisions) to form a solid mass of cells called as morula. Morula later changes to blastula (hollow ball of cells). This process take place in the first 5-6 days after fertilization.

Day 1: Zygote undergoes first cleavage to form two cells.

Day 2: The two cells undergoes second cleavage to form four-cell stage.

Day 3: 6-12 cell stage

Day 4: A solid ball of 16-32 cells are formed and is called as morula.

Day 5 - 6: Morula changes to hollow ball of cells called as bastula.