Mesokaryon occurs in

Options

A. Zooflagellates
B. Eulenoids
C. Sarcodines
D. Dinoflagellates.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Mesokaryon":**
- Mesokaryon refers to a specific type of nucleus that is characterized by the presence of condensed chromosomes. The term is derived from "meso," meaning middle, and "karyon," meaning nucleus.

2. **Identifying Where Mesokaryon Occurs:**
- Mesokaryon is primarily found in dinoflagellates. This group of protists exhibits unique nuclear characteristics that combine features of both prokaryotic and eukaryotic cells.

3. **Characteristics of Mesokaryon:**
- The nucleus in dinoflagellates is organized similarly to eukaryotic nuclei, which have a well-defined structure. However, the process of nuclear division in dinoflagellates resembles that of prokaryotes, where the chromosomes are not as distinctly organized.

4. **Conclusion:**
- Given the options provided (zooflagellates, ulinoids, sarcodenes, dinoflagellates), the correct answer is that mesokaryon occurs in **dinoflagellates**.

5. **Final Answer:**
- The correct option is **dinoflagellates**.

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