Answer to Question 1
Indole-3-acetic acid (IAA).
Answer to Question 2
Darwin described the effects of light on the movement of coleoptiles and suggested
that auxins were involved.
Went in 1928 developed a method for the quantification of plant hormones present
in a sample, which was called the Avena curvature bioassay.
Kogel and coworkers in 1934 were the first to purify heteroauxin (other auxin) from
human urine.