Question

how would you check the presence of starch in leaves?

Answer 1

Question:

How would you check the presence of starch in leaves?

Answer with Full Explaination:

First of all let us know about Starch.

• Starch is a white, powdery substance .

• It contains glucose molecules .

• It is used by plants.

So, now let's come to the required answer we need :

The presence of starch in leaves can be tested by the Iodine test. When we remove chlorophyll from the leaf by boiling it in alcohol and then put two drops of iodine solution, it is colour change to blue indicates the presence of starch.

Let's Know How To Test it :

To test leaves for the presence of starch,

• Let a leaf be boiled in water .

• In a boiling tube containing 90% ethanol (ethyl alcohol) put the boiled leaf here .

• The ethanol boils and the green colouring (chlorophyll) is removed from the leaf.

• Add the iodine reagent , this will cause the green areas on the leaf, where starch is supposedly present, to turn to a blue-black colour.

• This indicates the presence of starch in the leaf.

Happy Learning!!!

Answer 2

Iodine solution is used to test leaves for the presence of starch. You need to: heat a plant leaf in boiling water for 30 seconds (this stops its chemical reactions) heat it in boiling ethanol for a few minutes (this removes most of its colour)