Question

Indole-3-acetic acid (auxin) was first isolated from ______.

Options

• rice bran oil

• rhizopus

• human urine

• coleoptiles of oat seedlings

Answer 1

Indole-3-acetic acid (auxin) was first isolated from human urine.

Explanation:

Auxin was finally isolated from the tip of oat coleoptiles in the gelatin block by Dutch botanist Fritz W. Went in 1928. Following Went's achievement, human urine was used to isolate auxin, indole-3-acetic acid (IAA).