Page 24 - EM BIOLOGY NOTES 10TH CLASS PSR DIGITAL BOOKS

1. TEST THE PRESENCE OF STARCH IN LEAVES
AIM :
To test the presence of starch in leaves.
APPARATUS :
1. Beaker 2. Test tube 3. Water
4. Methylated spirit (Ethanol) 5. Tripod stand 6. Asbetos gauze
7. Bunsen burner 8. Petridish 9. Iodine solution
10. Leaf 11. Dropper
DIAGRAM :

PROCEDURE :
1. Take a leaf of potted plant.
2. Boil the leaf in methylated spirit over a water bath.
(if we boil the leaf in methylated spirit directly on bunsen burner, spirit will burn)
3. Till leaf becomes pale white.
(chlorophyll dissolved in the methylated spirit leaf become pale white)
4. Spread the leaf in a petridish.
5. Add a few drops of iodine on it.
OBSERVATION :
1. Leaf turns into blue-black colour.
2. It indicates that the leaf contains starch.
INFERENCE :
This experiment proves that leaf contains starch.
PRECAUTIONS :
1. We should boil the leaf in methylated spirit over a water bath carefully.
2. We should boil the leaf till it will become pale white.

TEACHER AND STUDENT PUBLICATIONS, ONLY 10TH CLASS (18) PSR DIGITAL BOOKS (ONLINE&OFFLINE), ALL SUBJECTS (TM&EM) 9885678410