SEEDLESS NON-VASCULAR PLANTS THE BRYOPHYTES Packet #69 Chapter #29 Review Book pg #131 Tuesday, September 08,

THE BRYOPHYTES Features That Distinguish Bryophytes From Green Algae and Other Plants Tuesday, September 08,

BRYOPHYTES 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 Bryophytes Diversity Figure 29.9 Page 582 Tuesday, September 08,

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. Tuesday, September 08,

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 Tuesday, September 08,

BRYOPHYTES Phyla of Pryophytes Tuesday, September 08,

PHYLUM BRYOPHYTA THE 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. Tuesday, September 08,

PHYLUM BRYOPHYTA THE 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. Tuesday, September 08,

PHYLUM BRYOPHYTA THE MOSSES Some mosses have separate sexes; while others bear both archegonia (female) and antheridia (male) on the same plant Tuesday, September 08,

PHYLUM BRYOPHYTA THE MOSSES 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 Steps 1 – 3 Page 581 Figure 29.8 Page 581 Tuesday, September 08,

PHYLUM BRYOPHYTA THE MOSSES—REPRODUCTION I 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. Step Page 581 Figure 29.8 Page 581 Tuesday, September 08,

PHYLUM BRYOPHYTA THE MOSSES—REPRODUCTION II 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. Step 8 Figure 29.8 Page 581 Tuesday, September 08,

LIFE CYCLE OF THE MOSSES GametophyteSporangium Tuesday, September 08,

LIFE CYCLE OF THE MOSSES SporangiumMature Sporangium Tuesday, September 08,

LIFE CYCLE OF THE MOSSES GerminationGametophyte Tuesday, September 08,

BRYOPHYTES—PHYLUM HEPATICOPHYTA The Liverworts Tuesday, September 08,

PHYLUM HEPATICOPHYTA THE 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. Tuesday, September 08,

PHYLUM HEPATICOPHYTA THE LIVERWORTS Liverworts have a dominant gametophyte generation. Reproduction is similar to that of the mosses. Tuesday, September 08,

BRYOPHYTES—PHYLUM ANTHOCEROTOPHYTA The Hornworts Tuesday, September 08,

PHYLUM ANTHOCEROTOPHYTA HORNWORTS Have thalloid gametophytes Hornworts resemble liverworts but may not be closely related to them. The sporophyte, that develops after fertilization, forms a “horn.” Tuesday, September 08,

REVIEW Tuesday, September 08,

REVIEW Students List potential examination questions and/or here, and on following slides, based on the packet. Tuesday, September 08,