Animal Cells:
* Cleavage furrow: Cytokinesis in animal cells begins with the formation of a cleavage furrow, an indentation on the cell surface.
* Actin and Myosin: This furrow is formed by a contractile ring made of microfilaments composed of actin and myosin proteins.
* Constriction: The ring contracts, pulling the plasma membrane inwards, eventually pinching off the cytoplasm and separating the two daughter cells.
Plant Cells:
* Cell Plate: Unlike animals, plant cells don't form a cleavage furrow. Instead, they build a cell plate, a new cell wall, between the two daughter cells.
* Golgi Apparatus: Vesicles from the Golgi apparatus carry cell wall materials like cellulose and pectins to the middle of the parent cell.
* Fusion: These vesicles fuse together, forming the cell plate which expands outward until it joins with the existing cell walls of the parent cell.
* New Cell Wall: This process ultimately divides the cytoplasm and creates two daughter cells, each with its own cell wall.
Here's a table summarizing the differences:
| Feature | Animal Cells | Plant Cells |
|---|---|---|
| Method | Cleavage furrow | Cell plate |
| Structure | Contractile ring of actin and myosin | Vesicles from Golgi apparatus |
| Process | Plasma membrane is pulled inwards | Cell plate expands outwards |
In essence:
* Animal cells use a constricting mechanism to divide cytoplasm.
* Plant cells use a building mechanism to construct a new cell wall between daughter cells.
This difference reflects the fundamental structural differences between animal and plant cells, specifically the presence of a rigid cell wall in plants.
