With respect to photoperiodism, site of perception of light/ dark duration is

Options

A. Root apex
B. Shoot apex
C. Flower
D. Leaf

Answer

To solve the question regarding the site of perception of light/dark duration in photoperiodism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Photoperiodism**:
- Photoperiodism refers to the physiological reaction of organisms to the length of day or night. In plants, it influences flowering, growth, and other developmental processes.

2. **Identify the Components**:
- The term "photo" refers to light, and "periodism" refers to the duration or period. This indicates that plants respond to the duration of light and darkness.

3. **Recognize the Types of Plants**:
- There are three main types of plants based on their photoperiodic responses:
- **Day Neutral Plants**: These plants do not depend on the length of day or night for flowering.
- **Short Day Plants**: These require longer nights (shorter days) to flower.
- **Long Day Plants**: These require shorter nights (longer days) to flower.

4. **Determine the Site of Perception**:
- The question asks for the site of perception of light/dark duration. In plants, this perception occurs in the leaves. The leaves contain photoreceptors that detect light and dark periods.

5. **Conclude the Answer**:
- Therefore, the correct answer to the question is that the site of perception of light/dark duration in photoperiodism is the **leaves** of the plants.

### Final Answer:
The site of perception of light/dark duration in photoperiodism is the **leaves**.

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