gamétophytes
A gametophyte is the haploid multicellular stage in the life cycle of land plants and algae. It is one of the two alternating phases of the plant life cycle, the other being the sporophyte. The gametophyte produces gametes, or sex cells, through a process of mitosis. In sexually reproducing plants, male gametes are typically sperm and female gametes are eggs. Fertilization occurs when a male gamete fuses with a female gamete, forming a diploid zygote. This zygote then develops into the sporophyte generation. The relative size and independence of the gametophyte generation vary significantly among different plant groups. In bryophytes, such as mosses and liverworts, the gametophyte is the dominant, free-living, and photosynthetic generation, while the sporophyte is smaller and dependent on the gametophyte. In vascular plants, including ferns, gymnosperms, and angiosperms, the sporophyte is the dominant generation. The gametophyte in these plants is reduced in size and often short-lived, developing within the tissues of the sporophyte. For example, in seed plants, the female gametophyte is contained within the ovule, and the male gametophyte is the pollen grain.