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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 clade includes all land plants (embryophytes) except for the bryophytes (liverworts, mosses and hornworts) whose sporophytes are normally unbranched, even if a few exceptional cases occur. [1] While the definition is independent of the presence of vascular tissue , all living polysporangiophytes also have vascular tissue, i.e., are vascular ...
Some liverworts, such as Marchantia, have a cuticle, and the sporophytes of mosses have both cuticles and stomata, which were important in the evolution of land plants. [ 3 ] All land plants have a life cycle with an alternation of generations between a diploid sporophyte and a haploid gametophyte , but in all non-vascular land plants, the ...
Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores. They are typically 0.2–10 cm (0.1–3.9 in) tall, though some species are much larger. Dawsonia, the tallest moss in the world, can grow to 50 cm (20 in) in height. There are approximately 12,000 species. [2]
No living land plant has equally dominant sporophytes and gametophytes, although some theories of the evolution of alternation of generations suggest that ancestral land plants did. Unequal (heteromorphy or anisomorphy). Gametophyte of Mnium hornum, a moss . Dominant gametophyte (gametophytic).
The last stage of the moss lifecycle is shown, where the sporophytes are visible before dispersion of their spores: the calyptra (1) is still attached to the capsule (3). The tops of the gametophytes (2) can be discerned as well. Inset shows the surrounding, black poplars growing on sandy loam on the bank of a kolk, with the detail area marked.
The tissue of sporophytes and gametophytes of vascular plants such as Rhynia preserved in the Rhynie chert is of similar complexity, which is taken to support this hypothesis. [ 32 ] [ 33 ] [ 34 ] By contrast, modern vascular plants, with the exception of Psilotum , have heteromorphic sporophytes and gametophytes in which the gametophytes ...
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. The diploid sporophytes appear only occasionally and remain attached to and nutritionally dependent on the gametophyte. [12]