Question

How would you test the presence of starch in leaves?

Answer 1

Answer:

Test for the presence of starch in leaves:

Aim: To study the presence of starch in leaves.

Apparatus: Beaker, test tube, bunsen burner, tripod stand, asbestos gauze, ethanol,leaf,petridish,iodine solution.

Procedure:

1. Select a leaf of a potted plant with soft and thin leaves.
2. Boil the leaf in methylated spirit over a water bath till it becomes pale white due to the removal of chlorophyll.
3. Spread the leaf in dish and add a few drops of tincture iodine/betadine solution on it.

Observation: The presence of starch will be indicated by a blue-black colour in leaf.

Result: The experiment proves that starch is present in leaves.

Answer 2

Answer:

using iodine

Explanation:

Aim:to test the presence of starch

Material required: potted plant,iodine/betadine solution,ethanol,petridish,water,bunsen burner,test tube

Procedure:

1. take a leaf from potted plant which is well exposed to sunlight
2. boil it in water
3. add ethanol solution to it so that it removes the chlorophyll
4. after this process you will observe the leaf to be pale,place it in a petridish
5. add two drops of iodine

Observation:you will observe that the leaf colour turn bluish black

Conclusion: the change in colour of leaf due to addition of iodine shows the presence of starch