Phototropic curvature is the result of uneven distribution of
Gibberellin
Phytochrome
Cytokinins
auxin
As we learnt in
Auxin -
Tryptophan is the precursor of Indole acetic acid (IAA, natural auxin). Important biassay of auxins are Avena curvature test and cross root inhibition test.
- wherein
Discovered by Went.
Darwin used germinating oat (Avena sativa) and canary grass (phalaris canaries) seeding in his experiments and hypothesised that when shoots were illuminated from one side, they bent forward the light in response to an influence, that was the tip of the shoot. In 1926, Frits Went discovered that some unidentified compound probably caused curvature of oat coleoptile towards the light, i.e, phototropism. The compound (auxin) found by Went is relatively abundant in coleoptile tips.
Option 1)
Gibberellin
Incorrect Option
Option 2)
Phytochrome
Incorrect Option
Option 3)
Cytokinins
Incorrect Option
Option 4)
auxin
Correct Option