BIOL-3040 Lecture Notes - Lecture 2: Gamete, Motility, Ginkgoales
Document Summary
Seedless vascular plants- multicellular embryo, alternation of heteromorphic generations. Phylum lycophodiophyta: lycopodiaceae (club mosses)- homosporous, selaginellaceae (selaginella)- heterosporous. Phylum monilophyta: ferns- homo and hetero, horsetails- homosporous, whisk ferns- homosporous. Bryophytes & vascular plants have a multicellular embryo and an alternation of heteromorphic generations (sporic meiosis) Ferns, conifers, angiosperms: sporophyte dominant, true xylem and phloem, lignin, apical meristems at stem, tips of sporophyte, specialized roots and shoots. Gymnosperms and angiosperms: seed structure that provides nutrition and protection for embryonic sporophyte. Spore produces bisexual gametophytes functionally unisexual sperm doesn"t fertilize egg of same gametophyte antheridia & archegonia are not mature at the same time. Outcrossing not selfing examples: club mosses, most ferns, horsetails, whisk ferns. Heterospory spores produce unisexual gametophytes: microspores male gametophytes (microgametophytes, megaspores female gametophytes (megagametophytes) Dominant condition found in selaginella, quillworts, water ferns arose independently several times. 1: spores can be used for flash powder/dragon"s breath. Required: sporophyte is eventually separated from gametophyte (different from bryophytes)
