How would you test the presence of starch in leaves?

• Take a potted plant with variegated leaves – for example, money plant or crotons.
• Keep the plant in a dark room for three days so that all the starch gets used up.
• Now select a leaf cover its portion with a black strip paper and keep the plant in sunlight for about six hours.
• Pluck the leaf from the plant. Mark the uncovered area in it and trace them on a sheet of paper.
• Dip the leaf in boiling water for a few minutes.
• After this, immerse it in a beaker containing alcohol.
• Carefully place the above beaker in a water-bath and heat till the alcohol begins to boil.
• Now dip the leaf in a dilute solution of iodine for a few minutes.
• Take out the leaf and rinse off the iodine solution.
• You observe that the presence of starch in various areas of the leaf which was uncovered.

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