Presence of cilated antherozoids in Dryopteris indicates

Options

A. Terrestrial habit
B. Aquatic ancestry
C. Both A and B
D. None of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the significance of ciliated antherozoids in Dryopteris, a type of fern. We need to determine what their presence indicates.

2. **Defining Antherozoids**: Antherozoids are the male gametes in plants, specifically in pteridophytes like Dryopteris. They are crucial for reproduction.

3. **Identifying Characteristics of Antherozoids**: The question specifies that the antherozoids in Dryopteris are ciliated. Ciliated means that they have hair-like structures (cilia) that help them move.

4. **Analyzing the Role of Cilia**: The presence of cilia suggests that these antherozoids can swim. This swimming ability is typically associated with aquatic environments, where the gametes need to move through water to reach the female gamete.

5. **Considering Habitat**:
- **Terrestrial Habitat**: In a terrestrial habitat, movement through water is not necessary for fertilization, as the gametes can be transferred directly.
- **Aquatic Ancestry**: Since the ciliated antherozoids can swim, it indicates that Dryopteris has an aquatic ancestry, as water is essential for the movement of these gametes.

6. **Evaluating the Options**:
- Option A (terrestrial habitat) is incorrect because cilia are not needed for movement on land.
- Option B (aquatic ancestry) is correct as the presence of ciliated antherozoids indicates a reliance on water for reproduction.
- Option C (both A and B) is incorrect because only B is true.
- Option D (none of the above) is also incorrect.

7. **Conclusion**: The presence of ciliated antherozoids in Dryopteris indicates aquatic ancestry.

**Final Answer**: Aquatic ancestry.

---