How does cytokinesis in plant cells differ from that in animal cells?
In animal cells, cytokinesis is achieved by the appearance of a furrow in the plasma membrane. The furrow gradually deepens and ultimately joins in the centre dividing the cell cytoplasm into two.
Plant cells, however, are enclosed by a relatively inextensible cell wall, therefore they undergo cytokinesis by a different mechanism. Wall formation starts in the centre of the cell and grows outward to meet the existing lateral walls.
The formation of the new cell wall begins with the formation of a simple precursor called the cell-plate that represents the middle lamella between the walls of two adjacent cells.
Explanation
The provided text highlights the structural difference driving the mechanism: animal cells lack a rigid wall, allowing a furrow to deepen, whereas plant cells have an inextensible cell wall. Consequently, plants form a cell-plate from the center outwards to complete division.
Solution Steps
Step 1: Describe the mechanism of cytokinesis in animal cells involving the formation of a furrow in the plasma membrane.
Step 2: Identify the presence of the inextensible cell wall in plant cells as the reason for a different mechanism.
Step 3: Explain the process in plant cells involving the formation of the cell-plate starting from the centre and growing outwards.