Which of the following statements about the effect of light color on the rate of photosynthesis in most green plants is correct?

• A. The rate of photosynthesis is higher in red light than in green light.
• B. The rate of photosynthesis is the same in both green and red light.
• C. Photosynthesis does not occur in either green or red light.
• D. The rate of photosynthesis is higher in green light than in red light.

Answer: (A)

Verified step by step guidance

1. Understand the concept of photosynthesis: Photosynthesis is the process by which green plants convert light energy into chemical energy stored in glucose. This process primarily occurs in chloroplasts, where pigments like chlorophyll absorb light.
2. Learn about chlorophyll's absorption spectrum: Chlorophyll, the main pigment in green plants, absorbs light most efficiently in the red and blue wavelengths of the visible spectrum. It reflects green light, which is why plants appear green.
3. Analyze the effect of light color on photosynthesis: Since chlorophyll absorbs red light more effectively than green light, the rate of photosynthesis is higher under red light compared to green light. Green light is less effective because it is mostly reflected rather than absorbed.
4. Evaluate the given options: Based on the absorption spectrum of chlorophyll, the correct statement is that the rate of photosynthesis is higher in red light than in green light. The other options can be ruled out because they contradict the known absorption properties of chlorophyll.
5. Conclude with scientific reasoning: The higher rate of photosynthesis in red light is due to the efficient absorption of red wavelengths by chlorophyll, which drives the light-dependent reactions of photosynthesis more effectively than green light.