Answer: Cell division and delays senescence.
- A Stem elongation by loosening cell walls at the subapical meristem
- B Cell division and delays senescence
- C Climacteric fruit ripening coupled with ethylene release
- D Primary root elongation exclusively, with no effect on lateral shoots
Correct answer: B. Cell division and delays senescence
Explanation: Cytokinins promote cell division, prevent senescence (aging), and promote lateral bud growth. They work together with auxins.
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.