What is not correct about mitosis ?

Options

A. Usually restricted to the diploid cells and haploid cells of some social insects
B. Furrow extends centripetally and microfilament ring brings about cleavage in plant cells .
C. Growth in multicellular organisms is a result of Mitosis
D. Meristematic tissues show mitosis

Answer

To determine what is not correct about mitosis, let's analyze the statements provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Mitosis**: Mitosis is a type of cell division that results in two daughter cells, each having the same number of chromosomes as the parent cell. It is essential for growth, development, and tissue repair in multicellular organisms.

2. **Statement Analysis**:
- **Statement 1**: "Usually restricted to diploid and haploid cells of some social insects."
- This statement is correct. Mitosis can occur in both diploid (2N) and haploid (N) cells, including those of social insects.

- **Statement 2**: "Furrow extends centripetally."
- This statement is also correct. In animal cells, during cytokinesis, a cleavage furrow forms and extends inward (centripetally) to divide the cell.

- **Statement 3**: "Microfilament ring brings about cleavage in plants."
- This statement is **not correct**. The microfilament ring, which is responsible for the cleavage furrow during cytokinesis, is found in animal cells, not in plant cells. In plants, a cell plate forms instead of a cleavage furrow.

- **Statement 4**: "Growth in multicellular organisms is a result of mitosis."
- This statement is correct. Mitosis is responsible for the growth and increase in the number of cells in multicellular organisms.

- **Statement 5**: "Meristematic tissues show mitosis."
- This statement is correct. Meristematic tissues, found in the tips of roots and shoots, are regions of active cell division and thus exhibit mitosis.

3. **Conclusion**: The statement that is not correct about mitosis is the one regarding the microfilament ring bringing about cleavage in plants.

### Final Answer:
The incorrect statement about mitosis is: "Microfilament ring brings about cleavage in plants."

---