A dikaryon is formed when

Options

A. meiosis is arrested
B. the two haploid cells do not fuse immediately
C. cytoplasm does not fuse
D. None of the above

Explanation

### Step-by-Step Text Solution:

1. **Understanding Dikaryon**: A dikaryon is a type of cell that contains two distinct nuclei. This is a key characteristic that defines a dikaryon.

2. **Formation of Dikaryon**: A dikaryon is formed when two somatic cells (or haploid cells) fuse together. However, it is important to note that while the cytoplasm of these cells fuses, their nuclei do not fuse immediately.

3. **Process Involved**: The fusion of the cytoplasm without the immediate fusion of the nuclei leads to the formation of a dikaryon. This condition is typically seen in certain fungi during their reproductive cycle.

4. **Exclusion of Meiosis**: It is important to clarify that meiosis does not result in the formation of a dikaryon. Instead, it leads to the formation of gametes, which are haploid cells.

5. **Identifying the Correct Option**: Given the options provided:
- Meiosis is arrested
- The two haploid cells do not fuse immediately
- Cytoplasm does not fuse
- None of the above

The correct answer is that the two haploid cells do not fuse immediately, which leads to the formation of a dikaryon.

### Final Answer:
A dikaryon is formed when the two haploid cells do not fuse immediately.

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