Which one of the following acids is a derivative of carotenoids?
- Indole-3-acetic acid
- Gibberellic acid
- Abscisic acid
- Indole butyric acid
Answer
(3) Abscisic acid
Solution
IAA and IBA are indole compounds (derived from the amino acid tryptophan), and gibberellic acid is a terpene (diterpene).
As per NCERT, the PGRs are of diverse chemical composition: indole compounds (IAA), adenine derivatives (kinetin), derivatives of carotenoids (abscisic acid, ABA), terpenes (gibberellic acid, GA3) or gases (ethylene).
Abscisic acid is a derivative of carotenoids.
Answer: (3)