In flowering plants the gametophyte phases are reduced to a few cells dependant for their nutrition on the Sporophyte. The gametophyte comprises the main plant, while the diploid sporophyte is much smaller and is attached to the gametophyte. Both spores and the resulting ganetophyte are haploid, which means they only have one set of chromosomes. The mature gametophyte produces male or female gametes by mitosis. The fusion of male and female gametes produces a diploid zygote which then develops into a new sporophyte.
The word sporophyte refers to the diploid multicellular stage in the life cycle of a plant or alga. This stage comes after the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one per each parent.
