Animal Cells:
* Cytokinesis by Furrowing: Animal cells divide their cytoplasm through a process called cleavage furrow formation. This involves:
* A contractile ring of microfilaments made of the protein actin forms just beneath the plasma membrane.
* The ring contracts, constricting the cell membrane and eventually pinching the cell in two.
* This forms two daughter cells with roughly equal amounts of cytoplasm.
Plant Cells:
* Cytokinesis by Cell Plate Formation: Plant cells have a rigid cell wall, preventing the formation of a cleavage furrow. Instead, they use a different mechanism:
* Cell Plate Formation: During telophase (final stage of mitosis), vesicles from the Golgi apparatus migrate to the center of the dividing cell.
* These vesicles fuse together, forming a cell plate.
* The cell plate grows outward, eventually merging with the existing cell wall.
* This cell plate divides the cytoplasm, ultimately creating two daughter cells with their own cell walls.
Other Differences:
* Centrioles: Animal cells have centrioles that play a role in spindle fiber formation during mitosis. Plant cells typically lack centrioles, though some exceptions exist.
* Cell Wall Formation: Animal cells do not have cell walls, while plant cells do, and the cell wall plays a crucial role in cytokinesis in plants.
* Cell Growth: Plant cells typically continue to grow after cytokinesis, while animal cells generally stop growing after division.
Summary Table:
| Feature | Animal Cells | Plant Cells |
|---|---|---|
| Cytokinesis | Cleavage furrow formation | Cell plate formation |
| Centrioles | Present | Absent (usually) |
| Cell Wall | Absent | Present |
| Cell Growth | Limited after division | Continuous growth after division |
In essence, the differences stem from the structural differences between animal and plant cells, particularly the presence of a rigid cell wall in plants.
