Which wavelengths of light are most effective in driving photosynthesis?

• A. Blue (around 450 nm) and red (around 680 nm) wavelengths
• B. Green (around 550 nm) wavelengths
• C. Ultraviolet (below 400 nm) wavelengths
• D. Infrared (above 700 nm) wavelengths

Answer: (A)

Verified step by step guidance

1. Understand the concept of photosynthesis: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. This process primarily occurs in chloroplasts and involves pigments like chlorophyll.
2. Learn about the absorption spectrum of chlorophyll: Chlorophyll absorbs light most effectively in the blue (around 450 nm) and red (around 680 nm) wavelengths. It reflects green light (around 550 nm), which is why plants appear green.
3. Analyze the role of different wavelengths: Blue and red wavelengths are most effective in driving photosynthesis because they are absorbed by chlorophyll and used in the light-dependent reactions. Green light is less effective because it is mostly reflected, while ultraviolet (below 400 nm) and infrared (above 700 nm) wavelengths are outside the range of absorption for chlorophyll.
4. Relate the wavelengths to the electromagnetic spectrum: The visible light spectrum ranges from approximately 400 nm to 700 nm. Photosynthesis is driven by light within this range, specifically blue and red wavelengths. Ultraviolet and infrared light fall outside this range and do not significantly contribute to photosynthesis.
5. Conclude by identifying the correct wavelengths: Based on the absorption spectrum of chlorophyll and the electromagnetic spectrum, blue (around 450 nm) and red (around 680 nm) wavelengths are the most effective in driving photosynthesis.