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Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes. Sporophytes produce haploid spores by meiosis , that grow into gametophytes. Bryophytes are gametophyte dominant, [ 11 ] meaning that the more prominent, longer-lived plant is the haploid gametophyte.
Bryophytes have the most elaborate gametophytes of all living land plants, and thus have a wide variety of gametangium positions and developmental patterns. Gametangia are typically borne on the tips of shoots, but may also be found in the axils of leaves, under thalli or on elaborate structures called gametangiophores. Bryophyte species may be:
In bryophytes (mosses, liverworts, and hornworts), the gametophyte is the most visible stage of the life cycle. The bryophyte gametophyte is longer lived, nutritionally independent, and the sporophytes are attached to the gametophytes and dependent on them. [5] When a moss spore germinates it grows to produce a filament of cells (called the ...
In all bryophytes, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack lignified water-conducting tissues, they cannot become as tall as most vascular plants. Algae, especially green algae. The algae consist of several ...
Most bryophytes, such as these mosses, produce stalked sporophytes from which their spores are released. The non-vascular land plants, namely the mosses (Bryophyta), hornworts (Anthocerotophyta), and liverworts (Marchantiophyta), are relatively small plants, often confined to environments that are humid or at least seasonally moist.
Antheridia and archegonia occur on different gametophytes, which are then called dioicous. The moss Mnium hornum has the gametophyte as the dominant generation. It is dioicous: male plants produce only antheridia in terminal rosettes, female plants produce only archegonia in the form of stalked capsules. [26] Seed plant gametophytes are also ...
In ferns and seed plants (including cycads, conifers, flowering plants, etc.) the sporophyte is the dominant generation; the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small. In bryophytes and ferns, the gametophytes are independent, free-living plants, while in seed plants, each ...
The ancestral sexual system in bryophytes is unknown but it has been suggested monoicy and dioicy evolved several times. [11] It has also been suggested that dioicy is a plesiomorphic character for bryophytes. [4]: 71 In order for dioicy to evolve from monoicy it needs two mutations, a male sterility mutation and a female sterility mutation. [11]