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GYMNOSPERMS

GYMNOSPERMS

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GYMNOSPERMS

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  1. GYMNOSPERMS Výukový materiál OR 03 - 86 Tvůrce: Mgr. Alena Výborná Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/03.0005 Tento projekt je spolufinancován ESF a SR ČR

  2. GYMNOSPERMS • „naked“ seeds = seeds without case • they are covered only by testa • they do not create the right flowers • flowers are substituted by cones • cones are usually lignifying and unisexual • eggs have no packaging

  3. GYMNOSPERMS • eggs sitting on the scales of the cones • easily accessible for pollen grains • pollen grains disseminated by wind= anemogamic plants • seeds of most conifers are spread by wind • yew, juniper and gingko produces seeds with fleshy parts - spread by animals

  4. CYCADS • ancient group • the first plants at the end of the Palaeozoic • the most widespread in the Mesozoic • nowadays, only a few species • mostly in Southeast Asia

  5. CYCADS

  6. GINGKOS • close relatives of conifers • living fossils • the biggest development in the Mesozoic • nowadays only one type– ginkgo biloba • origin in eastern China • it is grown in parks and gardens in our country • dioecious tree • deciduous leaves

  7. GINGKOS • leaves resemble the shape of a small fans • seeds resemble drupes

  8. CONIFERS • the narrow needle-like leaves • trees • mostly evergreens • the group includes the largest trees in the world -redwood • trees with racemose branches • resin ducts leading stem

  9. CONIFERS • reproduction: • eggs are without packaging • they are placed on the scales • cones can lignify • woody cones = cone responds to humidity (it opens with dry)

  10. CONIFERS • occurance: • frigeophilic (cold-liking) trees • they grow even on poor soils • they reached its greatest development in the Mesozoic

  11. CONIFERS • representatives: • Norway spruce • forest pine • silver fir • common larch • common juniper • red yew

  12. Revision: • 1) To what plant group are conifers classified? • Gymnosperms. • 2) Do egg have packaging? • No, they have not. • 3) How are the seeds of the yew, juniper and gingko spread ? • By animals • 4) Where is the origin of gingko bilba? • Eastern China • 5) Ancient group of gymnosperms is… • Cycads

  13. Source of texts and pictures: • DOBRORUKA, Luděk J. Přírodopis pro 7. ročník základní školy. 1. vyd. Praha: Scientia, 1998, 152 s. ISBN 80-718-3134-4