Question

Who discovered gibberellin?

• A. E. Kurosawa
• B. Miller
• C. Francis Darwin
• D. F.W. Went

Answer 1

The correct option is A E. Kurosawa

Gibberellin is a plant growth regulator that promotes growth in plants. E. Kurosawa, a Japanese botanist, discovered gibberellin in 1926 when he was investigating the foolish seedling disease of rice. This disease was caused by the fungal pathogen Gibberella fujikuroi. The chemical extracted from the fungus responsible for the changes was named gibberellic acid.

Miller identified and crystallised the cytokinesis promoting active substance termed as kinetin.

Charles Darwin and his son Francis Darwin observed that the coleoptiles of canary grass bent towards light. Coleoptile is a protective sheath of the emerging shoot apex in the monocot embryo. They observed that when unidirectional light shines on the coleoptile, it bends in the direction of the light (phototropism) source.

F. W. Went isolated auxin from the tips of coleoptiles of oat seedlings. Auxins are plant growth regulators. They are produced at the root apex and shoot apex of the plants.