BIO 1106 Study Guide - Quiz Guide: Prothallium, Lycopodiopsida, Ginkgo Biloba

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25 Aug 2016
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Key characteristics: autotrophic, got chlorophyll a, cell walls of cellulose, alternation of generations. Are the general group, not the phylum. Liverwort thalli - flattened dorsoventrally and bilaterally symmetrical. Moss thalli - erect and radially symmetric (circular) Alternation of generations: includes gametophyte and sporophyte. Have multicellular sex organs where gametes are-producing cells are enclosed in jacket of sterile cells: antheridia. Male sex organs that produce swimming, biflagellate sperm. Sperm must swim to eggs, requires water (rain or dew: archegonia. Some bryophytes have sperfm-delivery system that imporves rate of sexual reproduction: can be done through tiny insects unknowingly. Restrict focus to thallus-type liverwort: marchantia: gametophyte thallus grows as large, flat, photosynthetic structure on surface of ground. Can produce asexually through fragmentation: older, central portions die leaving growing tips isolated to form individual plants. Gemmae cups occur on upper surface of some thalli near midrib: represent another means of asexual reproduction, inside cups are lens-shaped outgrowths called gemmae.