Answer: thigmotropism.
- A thigmotropism
- B phototropism
- C geotropism
- D hydrotropism
Correct answer: A. thigmotropism
Explanation: Thigmotropism is growth in response to contact, seen in climbing tendrils.
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.