Assertion (A): Photosynthesis in green plants proceeds at a much higher rate under red and blue regions of the visible light spectrum. Reason (R): Chlorophyll pigments possess maximum absorption peaks corresponding precisely to the wavelengths of red and blue light.

💡 Solution & Explanation

Action spectra of photosynthesis match the absorption spectra of chlorophyll a and chlorophyll b, showing peak light absorption and photosynthetic activity in the blue and red regions of the visible spectrum, while green light is largely reflected. Carotenoids absorb accessory wavelengths and transfer energy to chlorophyll while protecting the photosynthetic apparatus from photo-oxidation. Sunlight drives the conversion of carbon dioxide and water into glucose and oxygen in chloroplasts.