The angiosperm plants also show the alternation of generation between the diploid sporophytic phase and the haploid gametophytic phase. In the life cycle of angiosperm the diploid sporophytic phase is the plant body itself. It is the larger and the prominent phase in the life cycle. The haploid gametophytic phase is small and is represented by the stages from the megaspores to egg and the microspore to the male gametophyte. The sporophytic plant produces the flower which bears the spores which later give rise to the male gametophyte. The male gametophyte gives rise to two sperms which fuses with the two cells of the 7-celled female gametophyte which is present within the ovule. Double fertilization is the characteristic feature of the angiosperms. Two sperms fertilize the two cells of the female gametophyte which results in the formation of a zygote which later forms the embryo and the other fusion products forms the triploid nutritive tissue known as the endosperm which nurtures the developing embryo. It is present within the sporophytic tissue which forms the seeds. The seeds on germination give rise to the sporophytic plant body.
