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).