Cytokinesis:
Cytokinesis is the process by which the cytoplasm of a parent cell divides to form two separate daughter cells after nuclear division. The mechanism of cytokinesis differs in plant cells and animal cells.
Cytokinesis in Animal Cells:
• Cytokinesis occurs by the formation of a cleavage furrow.
• A contractile ring made of actin and myosin filaments forms at the equatorial plane.
• The ring contracts inward, deepening the furrow.
• Finally, the cell is pinched into two daughter cells.
• This type of cytokinesis is called centripetal (from outside to inside).
Cytokinesis in Plant Cells:
• Plant cells have a rigid cell wall, so cleavage furrow formation is not possible.
• Cytokinesis occurs by the formation of a cell plate at the centre of the cell.
• Vesicles from the Golgi apparatus accumulate at the equatorial plane and fuse to form the cell plate.
• The cell plate grows outward and fuses with the existing cell wall.
• This type of cytokinesis is called centrifugal (from centre to periphery).
Difference between Cytokinesis in Plant and Animal Cells:
| Animal Cells | Plant Cells |
|---|---|
| Occurs by cleavage furrow | Occurs by cell plate formation |
| Involves contractile ring | Involves Golgi vesicles |
| Centripetal division | Centrifugal division |
| No cell wall present | Rigid cell wall present |
Conclusion:
Thus, cytokinesis in animal cells occurs by cleavage furrow formation, whereas in plant cells it takes place through cell plate formation due to the presence of a rigid cell wall.