SEEDLESS NON-VASCULAR PLANTS THE BRYOPHYTES

1. SEEDLESS NON-VASCULAR PLANTSTHE BRYOPHYTES Packet #69 Chapter #29 Review Book pg #131

2. THE BRYOPHYTES Features That Distinguish Bryophytes From Green Algae and Other Plants

3. BRYOPHYTES Bryophytes Diversity Figure 29.9Page 582 • Bryophytes include the mosses, liverworts and hornworts • Seedless plants that disperse via haploid spores • Have several adaptations that green algae, a protist, lack. • Cuticle • Stomata • Multi cellular gametangia

4. BRYOPHYTES II • Additionally, bryophytes are non-vascular plants. • Non-vascular plants lack vascular tissue, xylem and phloem, and limits them to moist environments a to small size • Bryophytes are the only plants with a dominant gametophyte generation. • Most of the life cycle is spent in the gametophyte generation. • Sporophytes, when developed, remain permanently attached and are nutritionally dependent on the gametophyte.

5. THE “EVOLUTION” CONNECTION • The evolution of bryophytes is based on fossil evidence of ancient plants and on structural and molecular evidence • However, the fossil record is very incomplete • Bryophytes may represent a side-line in evolution • Hornworts, a type of bryophyte, may be the most ancient based on structural and molecular evidence

6. BRYOPHYTES Phyla of Pryophytes

7. PHYLUM BRYOPHYTATHE MOSSES • Bryophytes have been distributed around the world from the tropics to the arctic. • They can exist in dry or cold habitats • They can practically desiccate • Rehydrates following rain events. • One wetland moss, Sphagnum, forms extensive deposits of peat.

8. PHYLUM BRYOPHYTATHE MOSSES • The mosses are colonial plants. • They have rhizoids that anchor the plant in the soil. • They lack true leaves, roots and stems • Alternation of generations is present.

9. PHYLUM BRYOPHYTATHE MOSSES • Some mosses have separate sexes; while others bear both archegonia (female) and antheridia (male) on the same plant

10. PHYLUM BRYOPHYTATHE MOSSES Steps 1 – 3Page 581 Figure 29.8Page 581 • Bryophytes have gametophytes that are green plants that grow from a filamentous protonema. • The protonema is a green filamentous growth that arises from spore germination and eventually gives rise to a mature gametophyte. • Found in liverworts and mosses

11. PHYLUM BRYOPHYTATHE MOSSES—REPRODUCTION I Step 4 - 7Page 581 Figure 29.8Page 581 • Flagellated sperm are transported to the archegonia by splashing raindrops and swim to the archegonia where they fertilize the egg • Diploid zygote grows into a multicellular sporophyte • Diploid sporophyte, attached to the gametophyte (archegonia) , grows as it receives nutrition.

12. PHYLUM BRYOPHYTATHE MOSSES—REPRODUCTION II Step 8 Figure 29.8Page 581 • The mature sporophyte undergoes meiosis to produce haploid spores • Spores are dispersed by wind. • Spore germinates. Grows into a protonema that forms a bud. • Protonema develops into the haploid gametophyte • The dominant stage.

13. LIFE CYCLE OF THE MOSSES Gametophyte Sporangium

14. LIFE CYCLE OF THE MOSSES Sporangium Mature Sporangium

15. LIFE CYCLE OF THE MOSSES Germination Gametophyte

16. BRYOPHYTES—PHYLUM HEPATICOPHYTA The Liverworts

17. PHYLUM HEPATICOPHYTATHE LIVERWORTS • Have gametophytes that are leafy or flattened, lobelike thalli. • The plant body is not differentiated into roots, stems and leaves—similar to what is seen in some algae, fungi and similar simple plantlike organisms.

18. PHYLUM HEPATICOPHYTATHE LIVERWORTS • Liverworts have a dominant gametophyte generation. • Reproduction is similar to that of the mosses.

19. BRYOPHYTES—PHYLUM ANTHOCEROTOPHYTA The Hornworts

20. PHYLUM ANTHOCEROTOPHYTAHORNWORTS • Have thalloid gametophytes • Hornworts resemble liverworts but may not be closely related to them. • The sporophyte, that develops after fertilization, forms a “horn.”

21. REVIEW

22. REVIEW • Students • List potential examination questions and/or here, and on following slides, based on the packet.