(1) A division or separation of form.
(2) (cell biology) The act or state of splitting or dividing of a cell, particularly during the telophase of (animal) cell division.
(3) (embryology) The repeated division of a fertilized ovum, producing a cluster of cells with the same size as the original zygote.
(4) (chemistry) The splitting of a large or complex molecule into smaller or simpler molecules.
In embryology, cleavage is the first stage of embryogenesis. It pertains to the repeated mitotic division of a zygote into blastomeres that cluster to a compact mass called morula. Cleavage continues until blastula is formed. The various types of cleavage are:
- Determinate cleavage vs. Indeterminate cleavage
- Holoblastic cleavage vs. Meroblastic cleavage
- Equal cleavage vs. Unequal cleavage
- Discoidal cleavage vs. Superficial cleavage
- Equatorial cleavage
- Enamel cleavage
- Cleavage furrow – A groove formed from the cell membrane in a dividing cell as the contractile ring tightens.