Answer: FLC (Flowering Locus C) - a repressor of flowering - silenced by vernalization through polycomb-mediated H3K27me3 marking.
- A Direct DNA methylation of the FT gene promoter region alone, with little histone involvement noted in typical laboratory settings
- B FLC (Flowering Locus C) - a repressor of flowering - silenced by vernalization through polycomb-mediated H3K27me3 marking
- C Gibberellin signaling acting mainly alone through the DELLA degradation pathway each time under usual circumstances
- D Mainly transcriptional control with little chromatin-level modification involved overall according to most researchers
Correct answer: B. FLC (Flowering Locus C) - a repressor of flowering - silenced by vernalization through polycomb-mediated H3K27me3 marking
Explanation: FLC represses flowering. Vernalization causes polycomb repressive complex (PRC2) to add H3K27me3 marks to FLC chromatin, silencing it. This allows FT expression and flowering.
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.