The chloroplasts of flowering land plants typically contain at least two photosynthetic pigments, chlorophyll a and chlorophyll b, that differ in the wavelengths of light they absorb. The synthesis of chlorophyll pigments from precursor molecules is a process that involves many sequential enzyme-catalyzed steps. Researchers studied the growth and photosynthetic ability of a plant that contained a mutant form of one of the enzymes required for chlorophyll biosynthesis.

Q1) Describe the effect on chlorophyll-containing photosystems when the chlorophyll molecules absorb photons of light.