Question

Which one of the following is NOT an auxin?

• A. Indole acetic acid (IAA)
• B. Indole butyric acid (IBA)
• C. 2,4-dichlorophenoxy acetic acid (2,4-D)
• D. 6-Benzylaminopurine (BAP)

Hint:

Auxins like IAA, IBA, and 2,4-D promote cell elongation. BAP is a cytokinin that promotes cell division, not elongation.

Answer 1

The Correct Option is D

Step 1: Understand auxins.
Auxins are plant hormones that regulate growth, especially cell elongation in shoots and roots. Common natural and synthetic auxins include:
IAA (Indole Acetic Acid) – a natural auxin
IBA (Indole Butyric Acid) – a synthetic auxin
2,4-D – a synthetic auxin, also used as a herbicide
Step 2: Identify the outlier.
BAP (6-Benzylaminopurine) is a cytokinin, not an auxin. Cytokinins promote cell division and shoot proliferation.
Conclusion:
Among the options, BAP is the only compound that is not an auxin.