Adaptation to Land?? z1. Waxy cuticle. z2. Gametangia - antheridia and archegonia. z3. Embryos - young sporophytes contained within protective tissues. z4. Pigments - protect against UV light. z5. Thick spore walls.
Classification of Plants
Evolution of Plants
K: Plantae Div: Hepatophyta
z -mitosis- zPlant Body - Gametophyte (n) > z---> Archegonium (n) ---> Eggs (n) z---> Antheridium (n) ---> Sperms (n) zSperm + Egg ---> Zygote (2n) ---> z *meiosis* zSporophyte (2n) ---> Sporocyte (2n) > Spore Tetrad (n) z -mitosis- zSpores (n) > Plant Body - Gametophyte (n) z“Alternation of Generations”
K: Plantae Div: Hepatophyta z1. Gametophyte (n) dominant. z2. Most are simple land plants restricted to moist environments. (No true vascular tissue.) Riccia
K: Plantae Div: Hepatophyta z1. Gametophyte (n) dominant. Usually flat thallus; z bilobed leafy structures. Rhizoids unicellular or z absent. z2. Most are simple land plants restricted to moist environments. (No true vascular tissue.) Riccia z3. Contain Oil bodies (90% species). z4. Apical Growth and posterior decay. z5. Sporophyte (2n) enclosed within calyptra and z pseudoperianth; seta may be present; z elaters present. z6. Evolved during the Devonian Period (375 mya).
K: Plantae Div: Hepatophyta Genus: Marchantia z1. Flat branches - thallus (plant body) may exceed 4 inches in length. z2. Surface of plant is cutinized. z3. Rhizoids emerge from ventral surface - tuberculate & smooth. z4. Single layer of photosynthetic cells in air chamber. z5. Single epidermal layer top; parenchmatous layers below.
K: Plantae Div: Hepatophyta Genus: Marchantia z6. Air pores - 4 tiers of cells (lower tier closes opening).
K: Plantae Div: Hepatophyta Genus: Marchantia z7. Vegetative plants form gemmae cups (gemmae). zLike “fragmentation”
K: Plantae Div: Hepatophyta Genus: Marchantia
z8. Sexual structures form on special branches - gametophores. yantheridiophores & archegoniophores
K: Plantae Div: Hepatophyta Genus: Marchantia z8. Sexual structures form on special branches - gametophores. yantheridiophores xantheridia in chambers below dorsal surface of disc; in rows xbiflagellated sperms discharged
K: Plantae Div: Hepatophyta Genus: Marchantia z8. Sexual structures form on special branches - gametophores. yarchigoniophores xarchegonia in chambers on ventral surface between arms; in rows xEgg at base. venter, pseudoperinanth, involucre, xcalyptra, capsule, stipe, foot
K: Plantae Div: Hepatophyta z -mitosis- zPlant Body - Gametophyte (n) > z---> Archegonium (n) ---> Eggs (n) z---> Antheridium (n) ---> Sperms (n) zSperm + Egg ---> Zygote (2n) ---> z *meiosis* zSporophyte (2n) ---> Sporocyte (2n) > Spore Tetrad (n) z -mitosis- zSpores (n) > Plant Body - Gametophyte (n) z“Alternation of Generations”
K: Plantae Div: Hepatophyta zspore tetrads zelators
K: Plantae Div: Bryophyta “Mosses” z1. Plant body leafy - mostly upright; z no lobes on branches. z2. Rhizoids of multicellualr filaments. z3. Growth of protenema apical. z4. Sporophyte (2n) enclosed within calyptra z and pseudoperianth; seta z5. Some have hydroids & leptoids. z (no lignin) z6. Branches have buds with z distinct tips. z7. Have primitive stomates.
K: Plantae Div: Bryophyta “Mosses”
yGametophores - leafy shoots xparaphyses - protective leafy shoots over sexual structure xacrocarpous - sex organs borne at the apices of leafy upright shoots. xpleurocarpous - sex organs born at the apices of leafy prostrate shoots.
K: Plantae Div: Bryophyta “Mosses”
zStructures of sporophyte: yfoot (haustorium) - yfilament - connects capsule to thallus yoperculum - cap yannulus - ring yperistome - teeth ycolumbula - sterile central mass ysporogeneous tissue - produces sporocytes and spores (n) ycalyptra - covers entire capsule ytapetum - nutritive tissue yapophysis - basal region of capsule; stomates
K: Plantae Div: Bryophyta “Mosses” yPolytrichum
K: Plantae Div: Bryophyta “Mosses” yFunaria
K: Plantae Div: Bryophyta “Mosses” yMnium
K: Plantae Div: Anthocerotophyta “Hornworts” y1. Thallus growth (like liverworts). y2. Sporophytes look like “horns”. y (continuous growth -> 20 cm). y3. No seta - basal region. y4. No protenema. y5. Rhizoids unicellular. y6. Have functioning stomates. y7. Sex organs (antheridium & y archegonium sunken in thallus. y8. Usually single plate-like y chloroplast in each cell.
K: Plantae Div: Anthocerotophyta “Hornworts”