Q. The phytohormone, which induces triple response growth is

A) IAA
B) ABA
C) $GA_{3}$
D) $C_{2}H_{4}$
Explanation

It was a Russian Physiologist named Dimitry N Neljubow (1876-1926), who first established that ethylene affects plant growth. He identified ethylene in illuminating gas but showed that it causes a triple response on pea seedlings- inhibited stem elongation, increased stem thickening and a horizontal growth habit.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.