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Pteridophytes. Vascular non seed plants. Remember that all plants share certain features in their life cycles: Multicellular haploid gametophyte stage, which produces haploid gametes (egg and sperm). Egg and sperm fuse to form diploid zygote .
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Remember that all plants share certain features in their life cycles: • Multicellularhaploid gametophyte stage, which produces haploid gametes (egg and sperm). • Egg and sperm fuse to form diploid zygote. • Multicellulardiploid sporophyte stage, which produces haploid spores by meiosis. • Haploid spores grow into haploid gametophytes.
Moss vs. Ferns • The biggest difference between fern life cycles and moss life cycles is that in ferns, the sporophyte is much bigger and longer-lived than the gametophyte. Fern gametophytes are typically only a few millimeters across.
Life Cycle • http://www.sciencelearn.org.nz/Contexts/Ferns/Sci-Media/Animations-and-Interactives/Fern-life-cycle • http://www.deanza.edu/faculty/mccauley/6a-labs-plants-02.htm
Heterosporous Plant • In ferns only the aquatic (water ferns) are heterosporous • Very important in evolution of seeds
A sporophyte produces two types of sporangia: micro- and megasporangia. • Microspores grow into microgametophytes that possess antheridia. • Megaspores grow into megagametophyteswith archegonia.
Sporangia • Fern sporangia: produces spores • Spore mother cell undergoes meiosis (2n →n) • Fern sporophytes (like all sporophytes) are diploid. Haploid spores are produced inside the sporangia via meiosis. The spores are eventually released, and they can grow into new haploid gametophytes.
Spores • Haploid (n) • Sporangia and spores with sporopollenin-enriched walls are key terrestrial adaptations of land plants • Spores are the main means of dispersal for all seedless plants
Assignment • 6th edition: • Read 590- 594 • Summarize each section (4 sections) • Pg. 596 Take the self quiz for 1- 15