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Adaptation to Land??. 1. Waxy cuticle . 2. Gametangia - antheridia and archegonia. 3. Embryos - young sporophytes contained within protective tissues. 4. Pigments - protect against UV light . 5. Thick spore walls . Classification of Plants. Evolution of Plants.
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Adaptation to Land?? • 1. Waxy cuticle. • 2. Gametangia - antheridia and archegonia. • 3. Embryos - young sporophytes contained within protective tissues. • 4. Pigments - protect against UV light. • 5. Thick spore walls.
K: Plantae Div:Hepatophyta • -mitosis- • Plant Body - Gametophyte (n) -----------> • ---> Archegonium (n) ---> Eggs (n) • ---> Antheridium (n) ---> Sperms (n) • Sperm + Egg ---> Zygote (2n) ---> • *meiosis* • Sporophyte (2n) ---> Sporocyte (2n) -----------> Spore Tetrad (n) • -mitosis- • Spores (n) -----------> Plant Body - Gametophyte (n) • “Alternation of Generations”
K:Plantae Div: Hepatophyta • 1. Gametophyte (n) dominant. • 2. Most are simple land plants restricted to moist environments. (No true vascular tissue.) Riccia
K:Plantae Div: Hepatophyta • 1. Gametophyte (n) dominant. Usually flat thallus; • bilobed leafy structures. Rhizoids unicellular or • absent. • 2. Most are simple land plants restricted to moist environments. (No true vascular tissue.) Riccia • 3. Contain Oil bodies (90% species). • 4. Apical Growth and posterior decay. • 5. Sporophyte (2n) enclosed within calyptra and • pseudoperianth; seta may be present; • elaters present. • 6. Evolved during the Devonian Period (375 mya).
K: Plantae Div: HepatophytaGenus: Marchantia • 1. Flat branches - thallus (plant body) may exceed 4 inches in length. • 2. Surface of plant is cutinized. • 3. Rhizoids emerge from ventral surface - tuberculate & smooth. • 4. Single layer of photosynthetic cells in air chamber. • 5. Single epidermal layer top; parenchmatous layers below.
K: Plantae Div: HepatophytaGenus: Marchantia • 6. Air pores - 4 tiers of cells (lower tier closes opening).
K: Plantae Div: HepatophytaGenus: Marchantia • 7. Vegetative plants form gemmae cups (gemmae). • Like “fragmentation”
K: Plantae Div: HepatophytaGenus: Marchantia • 8. Sexual structures form on special branches - gametophores. • antheridiophores & archegoniophores
K: Plantae Div: HepatophytaGenus: Marchantia • 8. Sexual structures form on special branches - gametophores. • antheridiophores • antheridia in chambers below dorsal surface of disc; in rows • biflagellated sperms discharged
K: Plantae Div: HepatophytaGenus: Marchantia • 8. Sexual structures form on special branches - gametophores. • archigoniophores • archegonia in chambers on ventral surface between arms; in rows • Egg at base. venter, pseudoperinanth, involucre, • calyptra, capsule, stipe, foot
K: Plantae Div:Hepatophyta • -mitosis- • Plant Body - Gametophyte (n) -----------> • ---> Archegonium (n) ---> Eggs (n) • ---> Antheridium (n) ---> Sperms (n) • Sperm + Egg ---> Zygote (2n) ---> • *meiosis* • Sporophyte (2n) ---> Sporocyte (2n) -----------> Spore Tetrad (n) • -mitosis- • Spores (n) -----------> Plant Body - Gametophyte (n) • “Alternation of Generations”
K: Plantae Div:Hepatophyta • spore tetrads • elators
K: Plantae Div: Bryophyta “Mosses” • 1. Plant body leafy - mostly upright; • no lobes on branches. • 2. Rhizoids of multicellualr filaments. • 3. Growth of protenema apical. • 4. Sporophyte (2n) enclosed within calyptra • and pseudoperianth; seta • 5. Some have hydroids & leptoids. • (no lignin) • 6. Branches have buds with • distinct tips. • 7. Have primitive stomates.
K: Plantae Div: Bryophyta “Mosses” • Gametophores - leafy shoots • paraphyses - protective leafy shoots over sexual structure • acrocarpous - sex organs borne at the apices of leafy upright shoots. • pleurocarpous - sex organs born at the apices of leafyprostrate shoots.
K: Plantae Div: Bryophyta “Mosses” • Structures of sporophyte: • foot (haustorium) - • filament - connects capsule to thallus • operculum - cap • annulus - ring • peristome - teeth • columbula - sterile central mass • sporogeneous tissue - produces sporocytes and spores (n) • calyptra - covers entire capsule • tapetum - nutritive tissue • apophysis - basal region of capsule; stomates
K: Plantae Div: Bryophyta “Mosses” • Polytrichum
K: Plantae Div: Bryophyta “Mosses” • Funaria
K: Plantae Div: Anthocerotophyta “Hornworts” • 1. Thallus growth (like liverworts). • 2. Sporophytes look like “horns”. • (continuous growth -> 20 cm). • 3. No seta - basal region. • 4. No protenema. • 5. Rhizoids unicellular. • 6. Have functioning stomates. • 7. Sex organs (antheridium & • archegonium sunken in thallus. • 8. Usually single plate-like • chloroplast in each cell.