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Gymnosperms

Gymnosperms

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Gymnosperms

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  1. Gymnosperms

  2. Group 3: Seed producing, Vascular Plants • Gymnosperms • Cycads • Ginko • Conifers • Angiosperms

  3. Seeds and their advantages 1) Seed plants don’t depend on water to reproduce Pollen (contains sperm) carried by wind/animals Zygote hardens into a seed 2) Embryo has… Nourishment: Nutrients inside feed embryo Protection: Hard shell 3) Allow dispersal Carried by wind, water, animals Some seeds are “dispersed” by animals Some seeds have “wings”

  4. Seeds and their advantages 1) Seed plants don’t depend on water to reproduce Pollen (contains sperm) carried by wind/animals Zygote hardens into a seed 2) Embryo has… Nourishishment: Nutrients inside feed embryo Protection: Hard shell 3) Allow dispersal Carried by wind, water, animals

  5. Seeds and their advantages 1) Seed plants don’t depend on water to reproduce Pollen (contains sperm) carried by wind/animals Zygote hardens into a seed 2) Embryo has… Nourishishment: Nutrients inside feed embryo Protection: Hard shell 3) Allow dispersal Carried by wind, water, animals

  6. Group 3: Seed producing, Vascular Plants Type 1: Gymnosperms Needle-like leaves (reduces water loss) Common to lumber industry Seeds enclosed in cones Male cones: produce pollen (pollen cone) Female cones: produce eggs (seed cone) Zygote hardens into seed (protected inside cones) Ex: Evergreen, Pine, Redwood, Cedar

  7. Conifer Life Cycle • Sporophyte phase (dominant) • Cones grow on tree • Male cones • Spores created by meiosis & released • Spores develop into pollen • Female cones • Spores created by meiosis • Male pollen lands on female cone • Pollen tube grows towards egg • Sperm travels down pollen tube • Spore hardens into seed • Seed released & grows into new sporophyte . p seed Z e

  8. Conifer Life Cycle • Sporophyte phase (dominant) • Cones grow on tree • Male cones • Spores created by meiosis & released • Spores develop into pollen • Female cones • Spores created by meiosis • Egg forms inside spore • Male pollen lands on female cone • Pollen tube grows towards egg • Sperm travels down pollen tube • Spore hardens into seed • Seed released & grows into new sporophyte

  9. 1) Male and female seed cones grow on adult sporophytes

  10. 2) Pollen grains released from the male seed cones -- Pollen is the male gametophyte Let’s zoom into the female seed cone…

  11. 3) Pollen grain sticks to the female ovule 4) Pollen tube grows from the male spore 5) Two sperm travel into female spore - one fertilizes the egg 6) Diploid embryo develops inside female cone (sporophyte stage restarts)

  12. 7) After seeds harden, the cone reopens and the seeds are released

  13. 8) Seed will land Ground

  14. 9) Seedling grows into (sporophyte)…the cycle repeats Ground

  15. female male

  16. Plant Life Cycle Comparisons

  17. Review • Name three advantages of seeds. • Which structure will protect gymnosperm seeds? • What do male cones produce? • What do female cones produce? • What is created when the sperm and egg fuse: sporophyte or gametophyte?