(embryology) The complete division of an isolecithal or microlecithal egg into blastomeres.
Depending mostly on the amount of yolk in the egg, the cleavage can be holoblastic (complete or total) or meroblastic (partial). The holoblastic type of cleavage is commonly seen in eggs containing moderate to sparse amount of yolk. Examples of animals with eggs that divide holoblastically include the amphibians, mammals, echinoderms, annelids, flatworms, nematodes, etc.
- compete cleavage
- total cleavage
Compare: meroblastic cleavage