Answer: Response of plants to the relative lengths of day and night for flowering.
- A The overall rate of carbon fixation occurring during daylight hours
- B Response of plants to the relative lengths of day and night for flowering
- C Light-induced changes in chlorophyll concentration affecting leaf color
- D Rapid guard cell turgor changes that open stomata at sunrise
Correct answer: B. Response of plants to the relative lengths of day and night for flowering
Explanation: Photoperiodism: flowering controlled by relative length of dark period (night). Plants classified as short-day, long-day, or day-neutral.
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.