Double fertilisation is the combination of syngamy and triple fusion. Double fertilization is unique to flowering plants. Events during fertilisation are elucidated.\xa0*As the pollen grain falls on the stigma of the flower, it germinates and forms a pollen tube. Pollen tube is guided by the secretions of the ovule. Pollen tube enters the micropylar region of the ovule.\xa0*Embryo sac inside an ovule consists of antipodals, synergids, egg cell, a central cell with two polar nuclei.\xa0*As the pollen tube releases two male gametes into synergids cytoplasm. One of the male gametes fuses with the nucleus of egg cell by the process of syngamy (first fertilisation) to form diploid zygote(2n).\xa0*The other male gamete fuses with the central cell and forms primary endosperm nucleus (PEN). This fusion is called as triple fusion. After the triple fusion the central cell is called as primary endosperm cell.