The process of fusion of two compatible gametes to form a zygote . This term is usually used to describe the leaves of palms and ferns. An organ of the gametophyte in which gametes develop. See antheridium , oogonium , archegonium . The multicellular haploid phase in the lifecycle of organisms with zygotic or sporic meiosis life cycles.
Gametophytes produce gametes via mitosis in structures called gametangia .
Unisexual male and female gametophytes may be referred to as microgametophytes and megagametophytes , respectively. See also sporophyte . The gametophyte is the dominant stage in the life cycles of liverworts, mosses, and hornworts. A gymnosperm lineage represented by a single extant species, Ginkgo biloba , commonly cultivated dioecious trees with easily-recognized leaves. The gymnosperm lineage thought to be most closely related to flowering plants.