Which of the following is the method of cytokinesis in plant cell :-

Options

A. By cell plate formation
B. By constriction
C. By phragmoplast
D. (A) and (C) both

Answer

To determine the method of cytokinesis in plant cells, we can analyze the options provided and the process involved in plant cell division.

### Step-by-Step Solution:

1. **Understanding Cytokinesis**: Cytokinesis is the process where the cytoplasm of a parental cell divides into two daughter cells. In plant cells, this process is distinct from that in animal cells.

2. **Formation of the Cell Plate**: In plant cells, during cytokinesis, vesicles derived from the Golgi apparatus gather at the center of the cell. These vesicles contain cell wall materials.

3. **Vesicle Alignment**: The vesicles align at the center of the cell and begin to fuse together, forming a structure known as the cell plate.

4. **Cell Plate Development**: As more vesicles fuse, the cell plate enlarges and eventually fuses with the existing cell membrane, leading to the formation of two separate daughter cells, each with its own cell wall.

5. **Phragmoplast Formation**: During late cytokinesis, structures called phragmoplasts form. These are microtubule structures that help guide the vesicles to the center of the cell and support the development of the cell plate.

6. **Analyzing the Options**:
- **Option 1: Cell Plate Formation** - This is the primary method of cytokinesis in plant cells.
- **Option 2: Constriction** - This method is characteristic of animal cells, not plant cells.
- **Option 3: Phragmoplast** - While phragmoplasts are involved in the process, they are not the method of cytokinesis itself but rather a structure that aids in the process.
- **Option 4: A and C both** - This option suggests that both cell plate formation and phragmoplast are correct, which is true as both are involved in the cytokinesis process.

7. **Conclusion**: The correct answer is **Option 4**, as it includes both the cell plate formation and the role of phragmoplasts in cytokinesis in plant cells.