pollen development stage K second mitotic division stage A pollen development stage (PO:0001007) during which the generative cell (PO:0020097) undergoes mitotic division to form two male gametes, the pollen sperm cells (PO:0025121). In taxa with mature two-celled pollen (PO:0025281), the second mitotic division takes place after pollen germination (GO:0009846), in the germinating pollen tube cell (PO:0025195). Note: This term overlaps with the GO BP term: generative cell mitosis (GO:0055047): The process in which the generative cell divides by mitosis to form two haploid cells. These will subsequently differentiate into sperm cells. PO:0001015 PO_GIT:509 plant_structure_development_stage pollen stage 9 in Arabidopsis (related) stamen stage ST6-4 (related) tricellular pollen development stage (exact) tricellular pollen stage (exact)