conifers l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Conifers PowerPoint Presentation
Download Presentation
Conifers

Loading in 2 Seconds...

play fullscreen
1 / 28
tamal

Conifers - PowerPoint PPT Presentation

151 Views
Download Presentation
Conifers
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Conifers BIOL 1407

  2. Seed Plants • Vascular Tissue • Produce seeds • Dispersal of offspring • Produce pollen • Sperm transfer without water

  3. Seed Plants • Sporophyte dominant • Gametophytes • Greatly reduced in size • Dependent on sporophyte

  4. Seed Plants • Heterosporous • Megaspore • Grows into female gametophyte  eggs • Microspore • Grows into male gametophyte  sperm • Photo Credit for Ovulate Cone: Dr. Stephen Bostic, ACC • Circled area: Ovule

  5. Pollen Production • Pollen cones have microsporophylls • Each microsporophyll has microsporangia • Photo Credit for Immature Male Pine Cones: Menchi, Wikimedia Commons

  6. Pollen Production • Meiosis occurs within microsporangia  microspores • Photo Credit for Staminate Cone: Dr. Stephen Bostic, ACC • Microsporangium circled in red • Microsporophyll at tip of yellow pointer • Microspores circled in pink

  7. Pollen Production • Microspores grow into male gametophytes • Male gametophyte = pollen grain

  8. Pollination • Pollen is released • Travels from male to female • Pollination occurs when pollen grain lands on female • http://www.youtube.com/watch?v=Bwl4g48-uIE

  9. Pollen Germination • After landing  pollen coat breaks open • 1 cell produces pollen tube • Photo Credit: Dr. David Byres, Florida Community College at Jacksonville

  10. Pollen Germination • A different cell produces 2 sperm cells by mitosis • They will move down pollen tube as it grows • Photo Credit: Dr. David Byres, Florida Community College at Jacksonville

  11. Pollen Germination • Pollen tube digests its way through female tissues to reach the egg

  12. Ovules • Ovulate cones have megasporophylls • Each megasporophyll has ovules containing megasporangia • Photo Credit for Immature Female Ponderosa Pine Cones: Susan McDougall @ USDA-NRCS PLANTS Database

  13. Ovules • Meiosis occurs within megasporangium  forms 1 megaspore and 3 haploid nuclei (degenerate) • Photo Credit: Dr. Stephen Bostic, ACC • Megasporangium circled in red • Megasporophyll at tip of yellow pointer

  14. Ovules • Megaspore grows into female gametophyte • Female gametophyte makes 1-2 eggs by mitosis

  15. Ovules • Integuments surround female gametophyte • Micropyle  lets pollen reach female gametophyte

  16. Ovules  Seeds • Integuments  seed coat • Female gametophyte  food supply • Fertilized egg  embryo

  17. Seeds • Dispersed by: • Wind • Animals • Water • Mechanical • Photo Credit for Pitch Pine Seeds: Steve Hurst @ USDA-NRCS PLANTS Database

  18. Types of Seed Plants • Gymnosperms • Naked Seeds • Not enclosed in ovaries • No fruits or flowers

  19. Types of Seed Plants • Angiosperms • Flowering Plants • Seeds enclosed in ovaries • Fruits and flowers

  20. Modern Gymnosperms • Conifers • Oldest living plants • Largest living plants • Widespread • Reproductive structure: Cones

  21. Modern Gymnosperms • Cycads • Wiry leaves • “Sago palms” • Ginkgos • Deciduous trees • One species • Herbal supplement

  22. Modern Gymnosperms • Gnetophytes • Ephedra (Mormon tea) • Welwitschia

  23. The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.