In plant cells, cytokinesis is characterized by the formation of which structure that divides the cytoplasm?

• A. Nucleus
• B. Chloroplast
• C. Cell plate
• D. Centrosome

Answer: (C)

In plant cells, cytokinesis divides the cytoplasm by building a cell plate at the center of the cell. Vesicles from the Golgi apparatus gather there and fuse to form this membrane-bound disk. The phragmoplast guides these vesicles as they coalesce and expand outward until the cell plate fuses with the existing plasma membrane, eventually developing into separating cell walls that split the cell into two daughter cells. This method works in plants because rigid cell walls prevent the cell from pinching in like animal cells do with a contractile ring.

The nucleus, chloroplast, and centrosome each have other roles—DNA housing, photosynthesis, and organizing microtubules, respectively—and do not directly build the boundary that divides the cytoplasm during plant cytokinesis.