Fig. 9 Action spectrum . The absorption and action spectra of chlorophyll.
a range of wavelengths of light within which a physiological process can take place. For example, the range of wavelengths of light in which the chlorophyll in green plants is able to synthesize carbohydrates by photosynthesis corresponds closely to the ABSORPTION SPECTRUM, showing that most of the light absorbed by chlorophyll is actually used in photosynthesis. See Fig. 9 .