Light effective in producing photoropism is

Options

A. Green
B. Red
C. Yellow
D. Blue

Answer

**Step-by-Step Solution:**

1. **Understanding Phototropism**: Phototropism is the growth response of plants to light direction. Plants tend to grow towards the light source, which is a positive phototropic response.

2. **Types of Light**: The question asks which type of light is most effective in producing phototropism. The options given are green, red, yellow, and blue light.

3. **Effects of Different Light Colors**:
- **Green Light**: Plants do not respond significantly to green light as it is mostly reflected rather than absorbed.
- **Red Light**: While red light can promote growth, it is not as effective as blue light in inducing phototropic responses.
- **Yellow Light**: Similar to green light, yellow light does not significantly influence phototropism.
- **Blue Light**: Blue light is known to be the most effective in promoting phototropism. Plants have photoreceptors that are sensitive to blue light, which triggers the growth response towards the light.

4. **Conclusion**: Based on the information about how different light colors affect plant growth and phototropism, blue light is the most effective in producing phototropism.

5. **Final Answer**: The light effective in producing phototropism is **blue light**.

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