Drooping/folding of legume leaves in dark is

Options

A. Temporary wilting
B. Nyctinasty
C. Seimonasty
D. Permanent wilting.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the phenomenon of drooping or folding of legume leaves in the dark. We need to identify the correct term that describes this movement.

2. **Analyzing the Options**: The options provided are:
- A) Temporary wilting
- B) Nictinosity
- C) Simonosity
- D) Permanent wilting

3. **Evaluating 'Wilting'**: Wilting generally occurs due to a decrease in turgor pressure within the plant cells. However, in this case, the question specifies that the drooping occurs in the dark, which suggests a different mechanism rather than a loss of turgor pressure.

4. **Understanding Plant Movements**: Plant movements can be classified into different types based on the stimuli:
- Nictinasty (response to darkness)
- Simmonasty (response to touch or vibration)

5. **Identifying the Correct Term**: Since the question refers specifically to the response of legume leaves to darkness, the correct term is Nictinosity (or Nictinasty). This term describes the movement of leaves or flowers in response to the absence of light.

6. **Eliminating Incorrect Options**:
- Temporary wilting and permanent wilting are incorrect because they relate to turgor pressure changes, not the specific response to darkness.
- Simonosity is also incorrect as it pertains to movements due to touch or vibration, not darkness.

7. **Conclusion**: Therefore, the correct answer to the question is **B) Nictinosity**.

---