Cell Division Mechanisms in Animal and Plant Cells

Overview

Animal and plant cells undergo cell division, but the mechanisms differ due to structural differences.

Microfilaments: Composed of actin and myosin proteins.
- Involved in muscle contraction and cell movement.
- Form rings around the cell equator.
Cytokinesis in Animal Cells:
- Microfilaments form contractile rings attached to the cell membrane.
- Rings contract, creating a cleavage furrow.
- The cleavage furrow deepens, pinching the parent cell into two separate cells.

Cell Wall: Stiff and not easily pinched, leading to a different cytokinesis process.
Cytokinesis in Plant Cells:
- Golgi-derived vesicles filled with carbohydrates line up along the cell equator.
- Vesicles fuse to form a cell plate, dividing the parent cell into two daughter cells.
- Vesicle membranes fuse with the cell membrane to create a continuous membrane for each daughter cell.
- Carbohydrates from vesicles form the middle lamella of the new cell wall.
- Daughter cells secrete cellulose between their membrane and the middle lamella to create the primary cell wall.
- Some plants add cellulose and polysaccharides beneath the primary wall to form a thicker secondary wall.

Regulatory Proteins: Orchestrate interphase and mitosis events.
Cell Cycle Variability:
- Different cell types have varied cell cycle rates.
- Skin and intestinal cells divide continuously to replace old cells.
- Nerve and muscle cells in adults often exit the cell cycle, entering the G0 phase.
Factors Influencing Cell Division:
- Controlled by both internal and external factors.

Key Takeaway: Understanding the differences in cell division mechanisms and regulation between animal and plant cells is crucial for comprehending cellular processes and their implications in biology and medicine.