Spiral cleavage

Definition

Spiral cleavage is a form of embryonic development in which cells divide at oblique angles, creating a spiral pattern. It is characteristic of certain groups of invertebrates, including mollusks and annelids.

5 Must Know Facts For Your Next Test

1. Spiral cleavage is observed in protostomes.
2. The orientation of cell division during spiral cleavage results in cells that are offset from each other.
3. It typically occurs during the early stages of embryogenesis.
4. Spiral cleavage leads to determinate development, meaning the fate of each cell is predetermined.
5. Mollusks, annelids, and some other invertebrates exhibit spiral cleavage.

Review Questions

Related terms

Radial Cleavage: A type of embryonic development where cells divide parallel or perpendicular to the axis, resulting in a radial symmetry.

Protostome:

A group of animals characterized by having spiral cleavage and mouth formation from the blastopore.

Determinate Development: A type of development where the fate of each embryonic cell is determined early in division.