How does cytokinesis in plant cells differ from that in animal cells?

Mechanism of Cytokinesis:

In plant cells, cytokinesis occurs through the formation of a cell plate. Vesicles derived from the Golgi apparatus coalesce at the center of the cell, forming the cell plate, which expands outward until it fuses with the cell membrane, leading to the separation of the two daughter cells.

In animal cells, cytokinesis is achieved by the formation of a cleavage furrow. A contractile ring composed of actin and myosin filaments forms beneath the plasma membrane at the cell’s equator, constricting the cell membrane inward until the cell is pinched into two separate daughter cells.

Role of Structural Components:

Plant cells utilize a structure called the phragmoplast, composed of microtubules and other proteins, to guide the formation of the cell plate during cytokinesis.

Animal cells rely on the actin-myosin contractile ring to facilitate the ingression of the cleavage furrow during cytokinesis.

Direction of Cytoplasmic Division:

In plant cells, the cell plate formation begins at the center of the cell and progresses outward toward the cell walls, a process described as centrifugal.

In animal cells, the cleavage furrow starts at the periphery and moves inward toward the center of the cell, a process described as centripetal.

Presence of Cell Wall:

The rigid cell wall in plant cells necessitates the formation of a new dividing wall (cell plate) between the daughter cells during cytokinesis.

Animal cells lack a rigid cell wall, allowing the plasma membrane to be pinched inward by the contractile ring during cytokinesis.

Timing of Cytokinesis:

In plant cells, cytokinesis typically begins during telophase, following the completion of nuclear division.

In animal cells, cytokinesis often starts during late anaphase or early telophase, overlapping with the final stages of mitosis.

Outcome:

Both plant and animal cells ensure equal distribution of cytoplasmic contents and organelles between the two daughter cells through their respective cytokinesis mechanisms.