SSC MTS EXAM

Detailed explanation-1: -Their flowering is a response to the changing length of day and night as the season progresses. The phenomenon is called photoperiodism. It helps promote cross pollination. Some plants such as spinach, Arabidopsis, sugar beet and the radish flower only after exposure to long days and hence are called long-day plants.

Detailed explanation-2: -The floral meristem identity gene LFY is upregulated at the transcriptional level by GA. The flowering-time gene SOC1 is also upregulated by GA, whereas FPF1 and GA-MYB were proposed to mediate between GAs and the regulation of flowering time.

Detailed explanation-3: -The cloning of CONSTANS, a gene involved in the promotion of flowering, is described in addition to the phenotypes of double mutants of constans and mutations in other genes that influence flowering and meristem identity. The results are consistent with CONSTANS acting in the photoperiodic pathway to floral induction.