How does the mechanism of cytokinesis differ between plant and animal cells?
Solution
Correct Answer: Option B
The process of cytokinesis, which is the division of the cytoplasm following mitosis, differs significantly between plant and animal cells due to their structural differences.
- In animal cells, cytokinesis occurs through the formation of a cleavage furrow.
- This furrow is created by a contractile ring composed of actin and myosin filaments that constricts the cell membrane, gradually pinching the cell into two separate daughter cells.
- This mechanism allows the flexible animal cell membrane to be drawn inward until the cell divides.
- In contrast, plant cells cannot form a cleavage furrow because they have a rigid cell wall that does not allow inward pinching.
- Instead, plant cells undergo cytokinesis by building a cell plate at the center of the dividing cell.
- Vesicles derived from the Golgi apparatus fuse at the center of the cell, depositing cell wall materials which eventually develop into a new cell wall separating the two daughter cells.
Important Points:
- Animal cells form a cleavage furrow using a contractile ring.
- Plant cells form a cell plate that develops into a new cell wall.
- The rigid cell wall in plant cells prevents cleavage furrow formation.
- The mechanisms reflect adaptations to the physical structures of the respective cells.
This fundamental difference ensures successful division respective to the structural constraints of each cell type.
Reference: Molecular Biology of the Cell, 6th Edition, Chapter 18: Mitosis and Cytokinesis / Page 1020
- In animal cells, cytokinesis occurs through the formation of a cleavage furrow.
- This furrow is created by a contractile ring composed of actin and myosin filaments that constricts the cell membrane, gradually pinching the cell into two separate daughter cells.
- This mechanism allows the flexible animal cell membrane to be drawn inward until the cell divides.
- In contrast, plant cells cannot form a cleavage furrow because they have a rigid cell wall that does not allow inward pinching.
- Instead, plant cells undergo cytokinesis by building a cell plate at the center of the dividing cell.
- Vesicles derived from the Golgi apparatus fuse at the center of the cell, depositing cell wall materials which eventually develop into a new cell wall separating the two daughter cells.
Important Points:
- Animal cells form a cleavage furrow using a contractile ring.
- Plant cells form a cell plate that develops into a new cell wall.
- The rigid cell wall in plant cells prevents cleavage furrow formation.
- The mechanisms reflect adaptations to the physical structures of the respective cells.
This fundamental difference ensures successful division respective to the structural constraints of each cell type.
Reference: Molecular Biology of the Cell, 6th Edition, Chapter 18: Mitosis and Cytokinesis / Page 1020
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