A variegated leaf with green and yellow paths in used for an experiment to prove that chlorophyll is required for photosynthesis. Before the experiment, the green portions $(A)$ , and the pale yellow portions $(B)$ , are observed. What will be the color of $^{'} A^{'}$ just before and after the starch test? Also, write the equation of photosynthesis and mark well as validate from which molecule the by-product is obtained.

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Solution

The color of the green portion (A) before the starch test will be pale yellow because chlorophyll needs to be removed before the starch test. The color of the green portion (A) after the start test will be blue-black because of the reaction of iodine with the starch present in A.
The Equation of photosynthesis is :
6CO $_{2}$ + 6H $_{2}$ O + Light energy = C $_{6}$ H $_{12}$ O $_{6}$ + 6O $_{2}$ .
Oxygen is obtained from the water. H $_{2}$ O -> 2H $^{+}$ + 1/2O $_{2}$ .

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Figure

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