1. Land plants: origins seedless plants Biol 121, Fall 2010, Tom Buckley 22 Sep 10

2. Phylogeny of land plants Brown and golden algae green algae

3. land plants 2n embryo

4. Probable ancestor: algae at lake edges (periodic drying)

5. Plant evolution aquatic ancestors land plants nonvascular plants seedless vascular plants vascular plants seed plants naked-seeded plants vessel-seeded plants green algae mossesfernsconifersflowering plants

6. Diversification of land plants # of spp 9,000 100 15,000 1,200 12,000 800 250,000 Fig 29.7 seedless plants seed plants

7. Diversification of land plants gametophyte = dominant sporophyte = dominant Fig 29.7

8. Characters of land plants walled spores produced in sporangia function of spores?

9. Characters of land plants apical meristems function of apical meristems?

10. Phylum Bryophyta (mosses) Phylum Hepatophyta (liverworts) Phylum Anthocerophyta (hornworts)

11. liverworthornwort

12. bryophyte anatomy hydroidsleptoids stem x.s. photosynthetic cells leaf x.s.

13. bryophyte anatomy photosynthetic cells leaf x.s. epidermis hornwort stoma

14. Bryophyte life cycle Fig 29.8

15. gametes produced in gametangia male: antheridia female: archegonium Bryophyte life cycle Fig 29.8

16. Bryophyte life cycle Fig 29.8

17. Bryophyte life cycle Fig 29.8

18. Seedless vascular plants Phylum Pterophyta (ferns, horsetails & relatives) Phylum Lycophyta ("club mosses" & relatives)

19. Isoetes sp. ("quillwort")tree fern

20. Equisetum sp. ("horsetail")

21. Seedless vascular plants: new features Vascular tissue makes large plants possible Sporophyte is dominant Sporophylls: modified leaves that bear sporangia permits complex reproductive structures nonvascular vascular

22. Fern life cycle

24. Sporangium: spore container

25. Sorus (pl. sori) = cluster of sporangia indusiumsorus

26. Sori

27. Horsetails (Equisetum)Strobilus (pl. strobili) = cluster of sporangia

28. sporophyll sporangium Horsetails (Equisetum)

29. Whisk fern (Psilotum) Synangium = cluster of 3 fused sporangia

30. Spike moss (Selaginella) Phylum Lycophyta Club moss (Lycopodium)

31. Q: What is the ploidy level of the tissues indicated by arrows? (a)n n (b)n 2n (c)2n n (d)2n 2n AB Moss (Phylum Bryophyta) A B

32. Q: In which of the following are gametes haploid? (a)Phylum Bryophyta (b)Phylum Pterophyta (c)Phylum Lycophyta (d)All of the above

33. Alternation of generations meiosis diploid syngamy haploid diploid haploid meiosis syngamy