Monoicous plants are those species that bear both sperm and eggs on the same gametophyte. Dioicous plants are those that have gametophytes that produce only sperm or eggs but never both. The terms are used largely but not exclusively in the context of bryophytes. Both monoicous and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte. The states of being monoicous or dioicous are called monoicy and dioicy respectively.