Answer: FT protein (Flowering Locus T) produced in leaves, transported to shoot apex via phloem.
- A A specialized auxin derivative synthesized directly within the shoot apical meristem region
- B FT protein (Flowering Locus T) produced in leaves, transported to shoot apex via phloem
- C Gibberellin A3 synthesized locally within developing floral primordia tissue
- D A cytokinin variant transported acropetally upward from the root system below
Correct answer: B. FT protein (Flowering Locus T) produced in leaves, transported to shoot apex via phloem
Explanation: Florigen = FT (Flowering Locus T) protein. Produced in leaf phloem companion cells under inductive photoperiods, transported to shoot apical meristem where it activates flowering genes.
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.