Sexual reproduction of Spirogyra is an advanced feature as it shows

Options

A. Different size of motile sex organs
B. Same size of motile sex organs
C. Morphologically different sex organs
D. Physiologically differentiated sex organs

Answer

To answer the question "Sexual reproduction of Spirogyra is an advanced feature as it shows," we will analyze the options provided and determine the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding Spirogyra**:
- Spirogyra is a genus of freshwater green algae known for its spiral chloroplasts. It reproduces both asexually and sexually.

2. **Sexual Reproduction in Spirogyra**:
- The sexual reproduction in Spirogyra occurs through a process called conjugation. In this process, two filaments align and form gametes.

3. **Types of Gametes**:
- The gametes produced during conjugation are known as isogametes. Isogametes are morphologically similar, meaning they have the same shape and size.

4. **Physiological Differences**:
- Although the isogametes are morphologically similar, they are physiologically differentiated. This means that even though they look the same, they have different functions. One gamete is typically more active (male), while the other is passive (female).

5. **Evaluating the Options**:
- **Option A**: Different size of motile sex organs - Incorrect, as the gametes are of the same size and non-motile.
- **Option B**: Same size of motile sex organs - Incorrect, as the gametes are non-motile.
- **Option C**: Morphologically different sex organs - Incorrect, as the gametes are morphologically similar.
- **Option D**: Physiologically differentiated sex organs - Correct, as the gametes are morphologically similar but physiologically different.

6. **Conclusion**:
- The correct answer is that the sexual reproduction of Spirogyra is advanced because it shows **physiologically differentiated sex organs**.

### Final Answer:
The correct option is **physiologically differentiated sex organs**.

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