Question

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

Phototropism is caused by the differential distribution of

• A. IAA
• B. Kinetin
• C. Gibberellin
• D. Abscisic acid.

Answer 1

The correct option is A

IAA

The correct option is Option A

Explanation for the correct option:

IAA (Indole 3 Acetic acid):

1. It is synthesized from the amino acid tryptophan and is found in the shoot apex.
2. It is responsible for tropic movements such as phototropism and geotropism.
3. It is responsible for the cell elongation of the shoot segments.

Explanation of the incorrect options:

Option B:

Kinetin induces cell division in plants

Option C:

Gibberellin is involved in increasing internodal length in dwarf plants;

Option D:

Abscisic acid is involved in the growth inhibition and dormancy of plants.

Final Answer: Phototropism is caused by the differential distribution of IAA (Indole acetic acid)