BSC 116 Lecture Notes - Lecture 7: Non-Vascular Plant, Protonema, Bryophyte
27 Aug 2016
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Document Summary
Plants are photoautotrophs with complex life cycles. Multicellular, photosynthetic autotrophs (about 290,000 species: cell walls of cellulose, chloroplast with chlorophylls a and b, these traits found among protists as well. Evolved from single-celled, aquatic green algae: charophytes: supported by morphological/ biochemical evidence. Shapes of cellulose-synthesizing complexes, flagellated sperm morphology, details of cell division. Sporopollenin: tough outer coating of charophyte zygotes and plants spores: supported by molecular phylogenetic analyses. Kingdom plantae = embryophytes: some debate about where to draw the line. Plant life cycles are characterized by alternation of generations. Use living (and fossil) plants to infer their pattern of evolution. Traits of living plants and cladistic methods provide information about the order in which key traits appeared. Fossils (and molecular clocks) help us date clades. Major events in plant evolution: multicellularity, invasion of land (about 475 my, origin of vascular tissue (about 520 my, appearance of (extant) seed plants (about 305 my)
