Question

In which order, cytokinesis occurs in plants-
A. Centripetal
B. Centrifugal
C. Oblique
D. Equatorial

Answer 1

Hint: The physical process of the cell division cycle where the cytoplasm of the parental cell is divided into two daughter cells is called Cytokinesis. It normally takes place after mitosis.

Complete Answer:
In plant cells, as they have cell walls, a cell plate forms across the cell in the location of the old metaphase plate during telophase. The membrane-enclosed vesicles derived from the Golgi apparatus migrate to the center of the cell where the metaphase plate used to be and fuse to form a cell plate.

These components for the new cell plate are created and packaged by the endoplasmic reticulum and Golgi apparatus and are then sent to the phragmoplast, which builds the cell plate from the middle outward. The cell plate will start in the middle, and then the growing cell plate fuses with the existing plasma membrane, producing two daughter cells. Meanwhile, the phragmoplast microtubules move outward. Therefore, the division of cells is from inside to outside.

Let us analyze the options one by one:
- Option A: In Centripetal cell division, the cell membrane starts constricting from the outside and proceeds towards the inside, which leads to the formation of two daughter cells. Since the division of the cell is from outside to inside, this is an incorrect option.
- Option B: In Centrifugal cell division, the process starts in the center of the cell and proceeds outwards until the new cell plate fuses with the parental plasma membrane, leading to the formation of 2 daughter cells. Since the direction of cell division is from inside to outside, this is the correct option.
- Option C: Oblique Cytokinesis, occurs in the process of binary fission in species like Ceratium and some members of the kingdom Protista. In this, the plane is divided obliquely and it leads to the formation of two unequal daughter cells. Therefore, this is an incorrect option.
- Option D: Equatorial plane is the cell plane where the cell plate is formed and the sister chromatids are aligned in the cycle of cell division. Hence, this is an incorrect option.

Thus, the correct option is B) Centrifugal.

Note: The difference in cytokinesis pattern is observed in the plant cells due to the presence of cell walls which provide rigidity to their structure. This extracellular structure helps the plants to give their form. Cell walls are established by the spindle-shaped microtubule structures called Phragmoplasts.