Question

The rate of photosynthesis is maximum in which colour of light?

• A. In green light
• B. In red light
• C. In yellow light
• D. In purple light

Answer 1

The correct option is B In red light

The rate of photosynthesis is maximum in red light. This was proved by the Emerson enhancement effect that states that there is an increase in the rate of photosynthesis when the chloroplast is exposed to a light of wavelength 680 nm and 700 nm. When chloroplast is exposed to a light of 680 nm and 700 nm wavelength wavelengths simultaneously the rate of photosynthesis is much higher than the photosynthesis that takes place at a wavelength of the sum of the red light and far red light. Thus the correct answer is option B.