How can you test the presence of starch in leaf? What does the presence of starch indicate of (PLEASE ANSWER IN A FORMAL MANNER COS I NEED TO WRITE IT IN SCHOOL COPY)
Answers
Answer:
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 a leaf from the plant. Mark the uncovered area in it and trace them on a sheet of paper.
Dip a 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.
the leaves becomes blue- black which indicates the presence of starch in it