1. Conifers BIOL 1407

3. Seed Plants Vascular Tissue Produce seeds –Dispersal of offspring Produce pollen Sperm transfer without water

4. Seed Plants Sporophyte dominant Gametophytes –Greatly reduced in size –Dependent on sporophyte

5. 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

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

7. 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

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

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

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

11. 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

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

13. 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

14. 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

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

17. Ovules Integuments surround female gametophyte Micropyle  lets pollen reach female gametophyte

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

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

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

22. Types of Seed Plants Angiosperms –Flowering Plants –Seeds enclosed in ovaries –Fruits and flowers

24. Modern Gymnosperms Conifers –Oldest living plants –Largest living plants –Widespread –Reproductive structure: Cones

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

26. Modern Gymnosperms Gnetophytes –Ephedra (Mormon tea) –Welwitschia

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