Question

What is a cleavage furrow?

Answer 1

Cleavage:

1. The cellular divisions that occur in a zygote that leads to the formation of blastomeres is called cleavage.
2. It leads to an overall increase in the number of cells but not in the mass or size of the zygote.

Cleavage furrow:

1. A region of the cytoplasm begins to constrict prior to cleavage.
2. This is the section where the cytoplasmic constriction extends throughout the cell and leads to cytokinesis.
3. It involves the coordinated movement of the cytoskeletal proteins like actin, myosin, and microfibrils along with the Golgi and mitochondrial machinery.
4. The cleavage furrow first appears in the cytoplasmic plane where the first cleavage division takes place. This is usually a longitudinal plane.
5. The cleavage furrow also depends on the localisation of yolk in the egg.