Protists which are diploid reproduce sexually by the process of -

Options

A. Zygotic meiosis
B. Cyst formation
C. Binary fission
D. Gametic meiosis.

Answer

To answer the question regarding the reproduction of diploid protists, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Protists**:
- Protists are a diverse group of eukaryotic microorganisms, which can be unicellular or multicellular. They can reproduce both sexually and asexually.

2. **Identifying the Reproductive Process**:
- The question specifies that we are focusing on diploid protists that reproduce sexually.

3. **Types of Meiosis**:
- There are different types of meiosis:
- **Zygotic Meiosis**: This occurs in organisms where the zygote is the only diploid stage, leading to the production of haploid individuals.
- **Gametic Meiosis**: This is where diploid organisms undergo meiosis to produce haploid gametes, which then fuse during fertilization to form a diploid zygote.

4. **Correct Process for Diploid Protists**:
- Since we are discussing diploid protists, the correct reproductive process is **gametic meiosis**. In this process, diploid gamete mother cells undergo meiosis to produce haploid gametes.

5. **Examples of Diploid Protists**:
- Examples of protists that reproduce via gametic meiosis include diatoms and metazoans.

6. **Conclusion**:
- Therefore, the correct answer to the question is **gametic meiosis**.

### Final Answer:
**Gametic meiosis**

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