In the figure given below, the black line (upper) indicates action spectrum for photosynthesis and the lighter line (lower) indicates the absorption spectrum of chlorophyll a. Answer the following.


a. What does the action spectrum indicate? How can we plot an action spectrum?


b. How can we derive an absorption spectrum for any substance?


(a) The rates of photosynthesis indicate the action spectrum. The measurement is oxygen release the oxygen releases on y-axis and the wavelength on x-axis can be compared to the action spectrum. The absorption by pigments of different wavelengths, such as chlorophyll a as shown on this graph, can be demonstrated.

(b) The absorption of various wavelengths for a particular pigment can be done by the processing, such as chlorophyll a, or chlorophyll b, or any other pigment.


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