For germination of seed, which light is necessary
Which wavelength of light is responsible for best flowering

Options

A. Red
B. Green
C. Far red
D. Blue

Answer

### Step-by-Step Solution:

1. **Understanding Seed Germination**:
- Seed germination is the process by which a seed develops into a new plant. For this process to occur, certain environmental conditions must be met, including the presence of light.

2. **Identifying the Necessary Light for Germination**:
- The question asks which light is necessary for seed germination. Research indicates that red light is crucial for the germination of many seeds.

3. **Wavelength of Light for Best Flowering**:
- The second part of the question inquires about the wavelength of light responsible for optimal flowering. The specific wavelength that promotes flowering in many flowering plants is 660 nm.

4. **Linking Wavelength to Light Type**:
- The 660 nm wavelength is found in red light. Therefore, red light is the type of light that is responsible for stimulating flowering in plants.

5. **Photoblastic Seeds**:
- It is important to note that the seeds that require light for germination are known as photoblastic seeds. These seeds respond positively to light, particularly red light at 660 nm.

6. **Role of Phytochrome**:
- The phytochrome pigment in plants, specifically the form known as phytochrome PR, is sensitive to red light at 660 nm and plays a significant role in the germination process.

### Final Answers:
- **Light Necessary for Germination**: Red light
- **Wavelength Responsible for Best Flowering**: 660 nm