Notwithstanding their general similarity, the archegonia of mosses differ externally from antheridia in having a longer neck and longer stalk. |
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Studies on development of antheridia and antheridial dehiscence have been conducted by Davie and Hartman. |
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Each antheridial chamber incorporates several antheridia, all of which are developed from one antheridial initial. |
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On their release from the antheridia, the antherozoids must then swim through surface water to fertilize neighbouring egg cells. |
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Other aberrant gametophyte phenotypes were observed among the group of mutants that could form antheridia. |
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Meiosis occurs just before mating in well-differentiated oogonia and antheridia. |
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Since the asexual gametophyte does not form antheridia or archegonia, crosses to confirm its genotype could not be performed. |
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The parent also contains antheridia which produce sperm and an oogonium which produces the egg. |
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Others are larger and hermaphroditic, producing archegonia at first and, later, antheridia. |
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The receptacles are reproductive branches and contain many cavities with external pores which contain antheridia and oogonia, then through meiosis, sperm and egg are produced. |
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Fern gametes are free-swimming and a thin film of water is required for the male gametes to travel from the antheridia into the neck of the archcgonia to fertilize the eggs. |
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Numerous antherozoids are produced in the antheridia and they swim through the covering film of water to reach the archegonia, each of which contains a single egg cell. |
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Gametophytes first produced antheridia and archegonia after seven weeks of culture. |
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Sperm are flagellated and must swim from the antheridia that produce them to archegonia which may be on a different plant. |
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The exact arrangement of the antheridia and archegonia in monoicous plants varies. |
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Oogonia and antheridia occur in conceptacles embedded in receptacles on special branches. |
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Those gametophytes consisted of short, curved uniseriate filaments of 2-3 cells, some bearing antheridia. |
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Each gametophyte was also scored for the number of antheridia and archegonia present. |
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Thalli may contain antheridia or archegonia or both. |
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In all mosses the antheridia are more or less club shaped or spherical. |
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Sometimes between the archegonia and the antheridia there are some elongated, club shaped cell filaments, which probably shall store water and protect those organs from drying up. |
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Archegonia and antheridia may sit in the mossflowers in mixed groups, but they may also grow on different places on the same plant, or only on different plants. |
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Microscopic observations made it possible to verify the integrity and the proper development of the prothallia, and the presence of archegonia and antheridia. |
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The main division is between species in which the antheridia and archegonia occur on the same plant and those in which they occur on different plants. |
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The term monoicous may be used where antheridia and archegonia occur on the same gametophyte and the term dioicous where they occur on different gametophytes. |
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When mature antheridia were watered, the opercular cell and crescent-shaped cell were shed, and 32 spermatozoids were released from each antheridium. |
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Antheridia formed on the dorsal and ventral surfaces of the wing, while archegonia formed on the ventral surface of the anterior cushion. |
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