Question

How will you test a leaf for starch? Mention any precaution you will take?

✰Best answer needed​

Answer 1

Answer:-

✰Aim – To test a presence of starch in a leaf.

✰Material required – A leaf, test tubes, burner, iodine solution, alcohol, dropper

Procedure :-

• Pluck one of the green leaves that have been exposed to sunlight.
• Boil that leaf in water for 5 minutes to soften it.
• Then put the leaf in a test tube containing alcohol. Now, gently place this test tube in a beaker of warm water till the alcohol starts boiling. The chlorophyll will slowly get dissolved in the alcohol and the leaf will start losing its green colour.
• Now, remove the alcohol by washing the leaf with warm water. Then spread the leaf over a white tile and add some iodine solution to it.
• Wash the leaf with water to remove the iodine solution and then hold it in light.

Observation ⇒ The parts of leaf which have starch will turn blue-black.

Precautions:-

• Do not allow the water in the beaker to boil.
• The alcohol will dissolve the chlorophyll and leaf will lose its green colour.

Answer 2

Explanation:

when you add iodine to starch it turns blue black in colour

I have given 30 thanks to strenbr

plz thx my all answer