1
Dr. F. Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly-cut coleoptile stumps. Of what significance is this experiment?
- It made possible the isolation and exact identification of auxin.
- It is the basis for quantitative determination of small amounts of growth-promoting substances.
- It supports the hypothesis that IAA is auxin.
- It demonstrated polar movement of auxins.
Answer
(1) It made possible the isolation and exact identification of auxin.
Solution
Went placed coleoptile tips on agar blocks; the growth substance diffused into the agar.
⇒ An agar block placed on one side of a decapitated coleoptile caused bending, proving that a diffusible chemical from the tip causes growth.
As per NCERT, F.W. Went isolated auxin from the tips of coleoptiles of oat seedlings.
∴ The experiment made the isolation and identification of auxin possible.
Answer: (1)
AIPMT 2014