Multiple choice

Which of the following is not a hormone?

  1. GA3

  2. Ethylene

  3. Phytochrome

  4. Auxins

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phytochrome is a pigment found in plants that acts as a photoreceptor, not a hormone. GA3 (gibberellin), ethylene, and auxins are all well-known plant hormones.