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Seedless Plants. Plant Evolution. Plant Evolution. Nonvascular Seedless plants (Ordovician - 475 mya) Vascular Seedless plants (Devonian - 400 mya) Vascular Seed plants (Carboniferous - 360 mya) Flowering plants (Cretaceous - 130 mya). Plant Evolution (Common with Algae).
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Plant Evolution • Nonvascular Seedless plants • (Ordovician - 475 mya) • Vascular Seedless plants • (Devonian - 400 mya) • Vascular Seed plants • (Carboniferous - 360 mya) • Flowering plants • (Cretaceous - 130 mya)
Plant Evolution(Common with Algae) • Multicellular and Eukaryotic • Cell walls made of Cellulose • Chlorophyll a and b • Store excess sugar as starch
Charophyceans • Homologous Cell Walls • Peroxisome enzyme (Photorespiration) • Homologous Chloroplasts • Sperm ultrastructure • Phragmoplasts (Mitosis & Cytokinesis) • Genetic Relationships
Adaptations to Terrestrial Life • Apical Meristems • Multicellular Dependent Embryos • Alternation of Generation • Walled Spores produced in Sporangia • Other Adaptations • Cuticle, stomata, Xylem & Phloem, secondary compounds
Adaptations in Shallow Water Algae • Subjected to occasional drying • Protection of gametes and embryos in gametangia • Sporopollenin
Nonvascular Seedless plants Bryophyta Mosses Hepatophyta Liverworts Anthocerophyta Hornworts Vascular Seedless plants Lycophyta Club mosses Psilophyta Whiskferns Spenophyta Horsetails Pterophyta Ferns Classification of Seedless Plants
Nonvascular Seedless Plants • Plant is a thallus (no vascular tissue) • no true leaves, roots, stems • Embryophytes • gametangia • (antheridium and archegonium) • sporangium (produces spores)
Hepatophyta • Liverworts • Two forms • leafy (80%) • thalloid (20%)
Hepatophyta • Liverworts • Reproduction • asexual (gemmae cups) • sexual
Anthocerophyta • Hornworts • Similar to liverworts except for sporophytes • Most closely related to higher plants
Vascular Seedless Plants • Formation of vascular tissue • Xylem (water) • Phloem (food) • True leaves, roots, and stems • Lignin • Sporophyte generation dominate • Sperm with flagella
Lycophyta • Lycophytes • true leaves • microphylls • true stems • true roots • sporophylls • leaves that produce spores
Psilophyta • Whisk Ferns • no true leaves • no true roots
Sphenophyta • Horsetails • true leaves • microphylls • true stems • silica • true roots