Circinate ptyxis present in fern leaves is due to

Options

A. Epinasty
B. Hyponasty
C. Nutation
D. Movement of variation

Answer

**Step-by-Step Solution:**

1. **Understanding Circinate Ptyxis**:
- Circinate ptyxis refers to the coiled or rolled-up arrangement of young fern leaves. This is a common feature in ferns where the leaves (fronds) are tightly curled when they first emerge.

2. **Identifying the Types of Movements**:
- To answer the question, we need to understand different types of plant movements:
- **Epinasty**: This is the downward bending of leaves or parts of a plant.
- **Hyponasty**: This is the upward bending of leaves or parts of a plant.
- **Nutation**: This refers to the bending movement of plant parts due to unequal growth rates.
- **Gnastics**: This involves movements in response to stimuli.

3. **Analyzing the Options**:
- The question asks about the reason for circinate ptyxis in fern leaves. We need to determine which of the movements (epinasty, hyponasty, nutation, or gnastic movement) is responsible for the coiling of fern leaves.

4. **Relating to Circinate Ptyxis**:
- In the case of ferns, the young leaves are coiled and this coiling is primarily due to the upward bending of the leaf structure as it grows. This upward bending corresponds to hyponasty.

5. **Conclusion**:
- Therefore, the correct answer to the question is **Option B: Hyponasty**. This is because circinate ptyxis in fern leaves is a result of the upward bending of the leaves.

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