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Question
Describe fully one experiment with potted green plant to show that starch is not produced in the leaves when carbon dioxide is not available (diagrams essential)
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Solution
Experiment to show that starch is not produced in the leaves when carbon dioxide is not available:
a. A potted plant is kept in the dark for two days to destarch the leaves.
b. Take a wide mouth bottle and fill 1/ 3'd of it with caustic potash solution.
c. Insert half part of the leaf of potted plant in the bottle and do not let the leaf to
touch the solution in the bottle.
d. The apparatus is kept in sunlight for few hours.
e. The leaf is plucked and tested for starch.
f. Only the portion of the leaf which is outside the bottle turns blue and the part of
the leaf inside the bottle remains colourless because it did not get C0 2 for
photosynthesis. All the C02 present in the bottle was absorbed by caustic
solution.
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