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The gametophyte is the first and dominant phase of two alternating phases in a bryophyte's life cycle. This part of the life cycle consists of protonema (the preliminary stage where the propagule develops green thread-like filaments), the rhizoids (filaments growing beneath the bryophyte that help anchor the bryophyte to its substratum), the stem, the leaves, its reproductive structure ...
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 ...
Life cycle of a typical moss (Polytrichum commune) The moss life-cycle starts with a haploid spore that germinates to produce a protonema (pl. protonemata), which is either a mass of thread-like filaments or thalloid (flat and thallus-like). Massed moss protonemata typically look like a thin green felt, and may grow on damp soil, tree bark ...
Many club-moss gametophytes are mycoheterotrophic and long-lived, residing underground for several years before emerging from the ground and progressing to the sporophyte stage. [4] Lycopodiaceae and spikemosses (Selaginella) are the only vascular plants with biflagellate sperm, an ancestral trait in land plants otherwise only seen in bryophytes.
Young sporophytes of the common moss Tortula muralis. In mosses, the gametophyte is the dominant generation, while the sporophytes consist of sporangium-bearing stalks growing from the tips of the gametophytes Sporophytes of moss during spring In flowering plants, the sporophyte comprises the whole multicellular body except the pollen and ...
The bryophytes, which include liverworts, hornworts and mosses, can reproduce both sexually and vegetatively. The life cycles of these plants start with haploid spores that grow into the dominant form, which is a multicellular haploid gametophyte, with thalloid or leaf-like structures that photosynthesize. The gametophyte is the most commonly ...
Nearly 50 years of research links two common insecticides used in food, yards and households to dramatically lower sperm count in men worldwide, a new study found.
The entire gametophyte generation, with the sole exception of pollen grains (microgametophytes), is contained within the sporophyte. The life cycle of a dioecious flowering plant (angiosperm), the willow, has been outlined in some detail in an earlier section (A complex life cycle). The life cycle of a gymnosperm is similar.