AP BIOLOGY

Detailed explanation-1: -An action spectrum is a graph of the rate of biological effectiveness plotted against wavelength of light. It is related to absorption spectrum in many systems. Mathematically, it describes the inverse quantity of light required to evoke a constant response.

Detailed explanation-2: -So in conclusion, for photosynthesis, the most effective and efficient light is in the red region (600-700 nm), followed by the blue (400-500 nm) and then the green (500-600 nm). These blue, green, and red wavelengths (400-700 nm), are all recognized as photosynthetically active and are used by plants.

Detailed explanation-3: -The action spectrum of photosynthesis shows a high light absorption for violet/blue and orange/red and low absorption for green/yellow.

Detailed explanation-4: -The graphical curve showing the amount of energy of different wavelength of light absorbed by a pigment is called absorption spectrum. It is studied with the help of spectrophotometer.