Answer: Zeatin.
- A IAA
- B GA3
- C Ethephon
- D Zeatin
Correct answer: D. Zeatin
Explanation: Zeatin is a natural cytokinin originally obtained from maize kernels.
Geometric growth (where both daughter cells keep dividing) produces this classic S-shaped curve: a slow lag phase, a rapid exponential phase, and a levelling-off stationary phase as nutrients or space become limiting - the same fundamental pattern seen in population growth.
Concept context
Phases of plant growth, the five classical plant hormones plus newer ones, photoperiodism, vernalization, and seed dormancy.