Answer: tropism.
- A tropism
- B nastic movement
- C nerve reflex
- D circulation
Correct answer: A. tropism
Explanation: A tropism is directional growth toward or away from a stimulus.
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.