IAA and serotonin are derived (formed) from which of the following

Options

(a) Tryptophan
(b) Tyrosine
(c) Phenylalanine
(d) None of these

Correct Answer:

Tryptophan

Explanation:

Natural auxins are synthesized in physiologically active parts of plants such as shoot apices, leaf primordial and developing seeds, bud, embryos from amino acid tryptophan.