Suppose there were plants that had a high concentration of Chlorophyll b, but lacked chlorophyll a, would it carry out photosynthesis? Then why do plants have chlorophyll b and other accessory pigments?

A plant lacking chlorophyll a cannot carry out photosynthesis because chlorophyll a is the only pigment that drives the photochemical reactions in the reaction centres

Chlorophyll b and other accessory pigments absorb light in regions where chlorophyll a absorbs poorly and transfer the harvested excitation energy to chlorophyll a, thereby broadening the overall light absorption spectrum

Accessory pigments such as carotenoids and xanthophylls protect chlorophyll a from photo-oxidative damage by quenching excess energy and reactive oxygen species, preventing pigment degradation under high light

In shaded or low-light environments accessory pigments enable more efficient light harvesting by capturing green and other wavelengths that chlorophyll a alone cannot absorb effectively

Having multiple pigments allows plants to adjust their pigment composition in response to changing light conditions, optimizing photosynthetic efficiency and resilience across diverse environments