Question

Choose the correct answer from each of the four options given below:

Hormone stimulating internodal length in plants is

• A. Auxin
• B. Gibberellin
• C. Cytokinin
• D. ABA

Answer 1

The correct option is B

Gibberellin

The correct option is option B

Explanation for the correct option:

Gibberellin:

1. They are weakly acidic tetracyclic plant hormones that produce cell elongation of leaves and intact stems in the general and increased internodal length of genetically dwarf plants in particular.
2. The hormones are named after the fungus, 'Gibberella fujikuroi' which produces bakanae (foolish seedling) disease in rice.

Explanation for the incorrect options:

Option A:

They are weakly acidic plant hormones, which are capable of promoting cell elongation, especially of shoot segments at a concentration of less than 100 ppm that is inhibitory to roots.

Option C:

They are mildly alkaline plant hormones that promote cell division. Kinetin is a synthetic cytokinin.

Option D:

1. It is a mildly acidic general growth inhibitor of plants that counteracts growth-promoting hormones or reactions mediated by them.
2. Abscisic acid is also called the stress hormone.

Hence, the Hormone stimulating internodal length in plants is Gibberellin.