Plant Growth And Development Question 59

Question: The natural plant hormones were first isolated from:

Options:

A) Corn germ oil and human urine.

B) Cotton fruits, spinach leaves and rice plants.

C) Human urine and rice seedlings.

D) Spinach leaves and fungus Gibberella.

Show Answer

Answer:

Correct Answer: A

Solution:

[a] The first naturally occurring auxin was isolated by Kogl and Haagen-Smit (1931) from human urine.

It was identified as auxin-a (auxentriolic acid).

Later, in 1934 Kogl, Haagen-Smit and Erxleben obtained another auxin called auxin-b (auxenolonic acid) from corn germ oil (extracted from germinating corn seeds).