Question

Which of the following wavelengths of light is absorbed maximum for photosynthesis?
A. Red light
B. Blue light
C. Green light
D. Yellow light

Answer 1

Hint: Photosynthesis depends on the absorption of light which is done by the pigments in the leaves and chlorophyll a is the most important pigment which absorbs energy from blue and red wavelengths.

Complete answer:
First of all, you should know what photosynthesis is. Photosynthesis is a process in which green plants capture light energy and then convert it into chemical energy. Light energy is also used to convert water, carbon dioxide, minerals, etc. into oxygen and energy-rich compounds.
This process depends on the absorption of light which is done by the pigments in the leaves of the plants. There are many accessory pigments which contribute to the absorption of light but the most important is chlorophyll a which absorbs maximum energy from the blue and red wavelength.
Blue light is of higher frequency if we compare it to red light. Also, it has more energy in one photon if we compare it to red light. Blue light is also absorbed maximum during photosynthesis as compared to red light.
If we look at options, option A is Red light. It is an incorrect option as the red light is not absorbed maximum for photosynthesis but in the question that wavelength of light is asked which is absorbed maximum for photosynthesis and that is blue light not red light. Therefore, this option is incorrect and hence it gets eliminated.
Moving to option B i.e., Blue light. It is the correct option as blue light is absorbed maximum for photosynthesis as blue color comes first in spectrum light. Therefore, this option is correct.
Moving to option C i.e., Green light. It is an incorrect option as the green light is not absorbed maximum for photosynthesis but in the question that wavelength of light is asked which is absorbed maximum for photosynthesis and that is blue light not green light. Therefore, this option is incorrect and hence it gets eliminated.
Last option D is Yellow light. It is an incorrect option as the yellow light is not absorbed maximum for photosynthesis but in the question that wavelength of light is asked which is absorbed maximum for photosynthesis and that is blue light not yellow light. Therefore, this option is incorrect and hence it gets eliminated.

Hence, the correct answer is option (B).

Note: Since chlorophyll a absorbs maximum energy from the blue and red wavelength, blue light is absorbed maximum for photosynthesis than any other light and this color also comes first in spectrum light due to which this option becomes the correct one.