Aim: To show the growth of Avena coleoptile involves a chemical substance.
Apparatus: Oat seedlings (Avena sativa),coleoptile, a slice of agar, a sharp blade.
Procedure:
1. Take some oat seedlings.
2. Their coleoptile tips are cut off.
3. Place the tips on a slice of agar and leave them for about an hour.
4. Cut the agar into small blocks and place a block on one side each stump of the decapitated plants.
5. The plants were kept in the dark during the entire experiment.
6. Observe the plants after one hour.
Observation :
1. Within one hour a distinct bending away from the side on which the agar block was placed is observed.
2. Agar block that had not been contact with coleoptile doesn’t show any bending.
Conclusion : The coleoptile tip exerted its effect by means of a chemical stimulus such as an electrical impulse. This chemical stimuls came to be known as auxin.
