Answer: low temperature.
- A low temperature
- B high light
- C severe drought
- D strong heat
Correct answer: A. low temperature
Explanation: Vernalisation is the cold treatment that induces some plants to flower.
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.