Answer: Stem elongation and seed germination.
- A Adventitious root initiation exclusively, with no effect on shoot tissue
- B Stomatal closure via guard cell turgor loss under water stress
- C Stem elongation and seed germination
- D Climacteric fruit ripening through ethylene biosynthesis induction
Correct answer: C. Stem elongation and seed germination
Explanation: Gibberellins promote stem elongation (important in dwarf plants), seed germination, and flowering in some plants.
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.