Photosynthesis is most active in

Options

A. Sunlight
B. Yellow light
C. Red light
D. Green light

Answer

To determine the condition under which photosynthesis is most active, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, specifically glucose, using carbon dioxide and water.

2. **Identifying Light Wavelengths**: Photosynthesis occurs in the presence of light, and different wavelengths of light have varying effects on the rate of photosynthesis. The range of light that is effective for photosynthesis is known as Photosynthetically Active Radiation (PAR), which spans from approximately 400 nanometers (nm) to 700 nm.

3. **Evaluating the Options**: The options provided are:
- Sunlight
- Yellow light
- Red light
- Green light

4. **Analyzing Each Option**:
- **Sunlight**: Sunlight contains all wavelengths of light, including those in the PAR range. It is the most comprehensive source of light for photosynthesis.
- **Yellow Light**: This is a part of the visible spectrum but does not encompass the full range of effective wavelengths for photosynthesis.
- **Red Light**: Red light is indeed effective for photosynthesis and is one of the most utilized wavelengths within the PAR range.
- **Green Light**: Green light is less effective for photosynthesis because plants reflect green light rather than absorb it.

5. **Conclusion**: While red light is very effective for photosynthesis, the most active condition for photosynthesis occurs in sunlight because it includes all effective wavelengths, making it the best option.

### Final Answer:
Photosynthesis is most active in **sunlight**.

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