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    Gymnosperms

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    tapas kundu
    Gymnosperms are seed plants whose ovules and seeds are incompletely covered by sporophylls. There are three phyla of gymnosperms: Coniferophyta, Ginkgophyta, and Cycadophyta. Coniferophyta includes conifers like pine, spruce and fir which have needle-like or scale-like leaves and reproduce using cones. Ginkgophyta contains a single living species, Ginkgo biloba, which has unique fan-shaped leaves. Cycadophyta features cycads with stiff compound leaves and cone-like structures for reproduction.

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    Gymnosperms

    Uploaded by

    tapas kundu
    184 views11 pages
    Gymnosperms are seed plants whose ovules and seeds are incompletely covered by sporophylls. There are three phyla of gymnosperms: Coniferophyta, Ginkgophyta, and Cycadophyta. Coniferophyta includes conifers like pine, spruce and fir which have needle-like or scale-like leaves and reproduce using cones. Ginkgophyta contains a single living species, Ginkgo biloba, which has unique fan-shaped leaves. Cycadophyta features cycads with stiff compound leaves and cone-like structures for reproduction.

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    Gymnosperms are seed plants whose ovules and seeds are incompletely covered by sporophylls. There are three phyla of gymnosperms: Coniferophyta, Ginkgophyta, and Cycadophyta. Coniferophyta includes conifers like pine, spruce and fir which have needle-like or scale-like leaves and reproduce using cones. Ginkgophyta contains a single living species, Ginkgo biloba, which has unique fan-shaped leaves. Cycadophyta features cycads with stiff compound leaves and cone-like structures for reproduction.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    184 views11 pages

    Gymnosperms

    Uploaded by

    tapas kundu
    Gymnosperms are seed plants whose ovules and seeds are incompletely covered by sporophylls. There are three phyla of gymnosperms: Coniferophyta, Ginkgophyta, and Cycadophyta. Coniferophyta includes conifers like pine, spruce and fir which have needle-like or scale-like leaves and reproduce using cones. Ginkgophyta contains a single living species, Ginkgo biloba, which has unique fan-shaped leaves. Cycadophyta features cycads with stiff compound leaves and cone-like structures for reproduction.

    Copyright:

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    Download as PPT, PDF, TXT or read online from Scribd
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    of 11

    Gymnosperms

    Three older Phyla of seed plants whose ovules, and seeds, are incompletely covered by a sporophyll.

    08 Feb. 2012

    Gymnosperms.ppt

    Gymnosperms
    Three Phyla not closely related to Flowering Plants, nor to each other. All widespread in Mesozoic,
    dinner for dinosaurs

    08 Feb. 2012

    Gymnosperms.ppt

    Phylum Coniferophyta
    Leaves needle-like or scale-like Cones
    Sporophylls arranged around a stem Usually woody, sometimes soft & fleshy
    Junipers, yews
    08 Feb. 2012 Gymnosperms.ppt 3

    Phylum Coniferophyta
    Life cycle
    Ovules, and seeds, are incompletely covered by a sporophyll.

    08 Feb. 2012

    Gymnosperms.ppt

    Male & Female Cones

    08 Feb. 2012

    Gymnosperms.ppt

    Female cone
    longitudinal section (l.s.)

    08 Feb. 2012

    Gymnosperms.ppt

    Conifer Life Cycle


    Time to develop seed
    Formation of male & female cones, release of pollen, Spring, year = 0 Maturation of ovule, egg cells Fertilization. Spring, year = 1 Maturation of seeds Seeds released, Spring, year = 2
    08 Feb. 2012 Gymnosperms.ppt 7

    Uses of Conifers
    Economic use Lumber, plywood
    Pine, redwood, spruce, fir, white cedar

    Pulp for paper Resins, turpentine Medicine


    Taxol from Taxus spp. (yews)
    08 Feb. 2012 Gymnosperms.ppt 8

    Phylum Ginkgophyta
    Fan-shaped leaves
    Veins nearly parallel with dichotomous branching

    Thick swollen seed coat


    Butyric acid, foul smelling

    Ancient group unchanged in 200 million years


    08 Feb. 2012 Gymnosperms.ppt 9

    Phylum Cycadophyta
    Stiff compound leaves Vascular bundles spiral in stem Cone-like reproductive bodies.

    08 Feb. 2012

    Gymnosperms.ppt

    10

    Phylum Cycadophyta
    Web pages from Royal Botanical Garden, Sydney, Australia
    http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cyca d/cycintro.html http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cyca d/cycadop.html

    08 Feb. 2012

    Gymnosperms.ppt

    11

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