Effect of day length duration of plant development is .

Options

A. Chemotropism
B. Phototropism
C. Photoperidism
D. Photosynthesis

Answer

### Step-by-Step Solution

1. **Understanding Day Length and Plant Development**:
- Day length refers to the duration of light that plants receive during a 24-hour cycle. This duration affects various physiological processes in plants, including growth and flowering.

2. **Role of Sunlight in Plant Growth**:
- Sunlight is essential for photosynthesis, the process by which plants convert light energy into chemical energy (food). The amount of sunlight received can influence how well a plant grows.

3. **Defining Key Terms**:
- **Chemotropism**: This refers to the growth of a plant in response to chemical stimuli. It is not directly related to day length.
- **Phototropism**: This is the growth of a plant towards light. While it involves light, it does not specifically address the duration of light.
- **Photoperiodism**: This term specifically refers to the physiological reaction of organisms to the length of day or night. It directly relates to how plants respond to the duration of light and darkness, affecting their growth and development.
- **Photosynthesis**: This is the process of converting light energy into chemical energy. While it is crucial for plant growth, it does not specifically address the effect of day length.

4. **Identifying the Correct Answer**:
- Since the question asks about the effect of day length duration on plant development, the correct term that describes this phenomenon is **photoperiodism**. This term encompasses how varying lengths of day and night influence plant growth and developmental processes.

5. **Conclusion**:
- Therefore, the effect of day length duration on plant development is best described by the term **photoperiodism**.