In Chlamydomonas the term hologamy is applied to a mode of sexual reproduction in which

Options

A. Gametes are motile
B. Gametes are holozoic
C. The young unicellular thalli directly behave as gametes
D. The gametes are differentiated into male and female.

Answer

**Step-by-Step Solution:**

1. **Understanding Hologamy**: Hologamy refers to a type of sexual reproduction where the gametes are not differentiated into male and female. Instead, any young thallus can act as a gamete.

2. **Analyzing the Options**:
- **Option A: Gametes are motile**: This is incorrect because motile gametes are typically flagellated and are involved in isogamous reproduction, where gametes are similar in size and shape.
- **Option B: Gametes are holozoic**: This option is also incorrect as holozoic refers to organisms that ingest solid food, which is not relevant to the definition of hologamy.
- **Option C: The young unicellular thalli directly behave as gametes**: This option is correct. In Chlamydomonas, the young thalli can function as gametes, which is a characteristic of hologamy.
- **Option D: Gametes are differentiated into male and female**: This is incorrect as it describes anisogamous reproduction, where male and female gametes are distinct.

3. **Conclusion**: The correct answer is that in Chlamydomonas, hologamy is a mode of sexual reproduction where the young unicellular thalli directly behave as gametes.

**Final Answer**: The young unicellular thalli directly behave as gametes.

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