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Modern Protist Diversity. Plant Clades. Plant Clades. Phylum/Division Bryophyta. Phylum/Division Pterophyta. Phylum/Division Anthophyta. Phylum/Division Coniferophyta. The ancestor of all plants was a green alga
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Plant Clades Phylum/Division Bryophyta Phylum/Division Pterophyta Phylum/Division Anthophyta Phylum/Division Coniferophyta
The ancestor of all plants was a green alga • Green algae have plant-like chloroplasts, plant-like cell walls, and a plant-like energy storage molecule (starch)… etc. • The ancestor of plants probably was a green alga that lived whole or partially in very shallow water, perhaps susceptible to periodic drying up • Those algae that could continue to metabolize despite not being completely covered with water presumably possessed a selective advantage—including shading those algae restricted to water • The first roots were stems (stipes) that physically connected out-of-water portions of algae with still-in-water portions • Water diffused over short stems to keep above-water, actively photosynthesizing tissues from desiccating From Algae to Plants
Chara Gametangia Antheridium Oogonium
Algae: • Get minerals and water from surrounding water • Have their bodies supported by surrounding water • Their sperm and spores swim through the water Plants: • Get their Minerals and Water from soil • Soil is subject to desiccation • Soil also is opaque to sunlight • Do not have their weight supported by surrounding water • Do not have, or have less water for sperm and spores to swim through To survive on land, plant ancestors had to address these challenges The Challenges of Land
Waxy cuticles (water proofing) Stomata (holes in above) Dominant sporophyte Vascular tissue Woody tissue Pollen (non-motile sperm carrier; also male gametophyte) Seeds (embryo carrier) Flowers Fruit Plant Innovations
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit
Guard Cells no Air in, no Water out Air in, Water out
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit
vasculature Dominant Sporophyte
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit
90% of water passed up through Xylem is transpired out of plant through stomata Vasculature (etc.) Photosynthate moves down from leaves, Minerals and Water move up from roots
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit
“White rot fungi (such as this species) primarily digest lignin leaving the whitish strands of cellulose behind… brown rot fungi digest cellulose and leave the crumbling brown lignin behind.” Fungi Aerobic Decay
Plant Innovations Waxy cuticles Stomata Dominant sporophyte Vascular tissue Woody tissue Pollen Seeds Flowers Fruit Alternation of Generations
Diploid phase Syngamy Meiosis Gametes Spores Haploid phase Alternation of Generations
Syngamy Isogametes Anisogametes Oogamy
Chara – Only Zygote is Diploid Zygote Gametangia Antheridium Oogonium
Development of the sporophyte prior to meiosis Diploid parent (Sporophyte) Meiosis (delayed) Diploid zygote Haploid Spores Sperm (gamete) Egg ( gamete) Haploid parent (Gametophyte) Delaying Meiosis
Fruit and Seeds Pericarp the fruit wall (derived from the ovary of the pistil) which is composed of the exocarp, mesocarp and endocarp (the three layers are not always recognizable, eg. dry fruit)
Parts of a fruit • Peach • Endocarp the innermost layer of the pericarp (often hard, stony or papery) • Mesocarpthe middle layer of the pericarp (often fleshy) • Exocarp the outermost layer of the pericarp (often like a skin or peel).
Parts of a fruit • Rind--Lemon • tough, leathery covering on manyfruits either composed of the exocarp (melon) or the exocarp and mesocarp (orange).
Parts of a fruit • Apple • accessory tissue • fruit parts not directly derived from the ovary, for example, receptacle tissue of pomes (apple) and the husks of nuts (acorn, pecan).
Simple Fruit legume or pod • derived from a single flower with a single ovary (pistil). • dry dehiscent fruit--pericarp splits open at maturity.legume or pod contains one locule that splits along two sutures. (bean, pea, peanut, mimosa)
follicle • contains one locule that splits along one or more suture. (larkspur, sweet gum, magnolia) Follicle--Sweet Gum and Magnolia
capsule • contains three or more locules that split along three or more sutures. (okra, golden rain tree, tallow tree) Okra
Dry indehiscent fruit- • pericarp dries, but does not split open at maturity. • Samara one or two seeded with pericarp flattened into wings. (maple, ash) Ash
Caryopsis or grain • one seeded fruit with seed fused to the pericarp. (wheat, corn, grain)
Achene • one seeded fruit with seed free from pericarp. Sunflower
Nut • similiar to an achene, but one seeded by abortion and partially (acorn) or entirely enclosed by a husk. (pecan, walnut) Pecan and Oak
Fleshy fruit • pericarp does not dry at maturity • Berry entire pericarp is fleshy. (grape, tomato) Tomato
Pepo • a type of berry, with the exocarp as a hard rind. (melon, cucumbers, squash) Squash
Hesperidium • a type of berry, with the exocarp and mesocarp as a hard rind and the endocarp composed of juice vesicles. (citrus-orange, lemon, lime) Lemon
Drupe or stone • a single-seeded fruit with a skin-like exocarp (fuzzy or smooth) fleshy mesocarp and a hard stony endocarp. (peach, cherry, plum, coconut) Peach
Pome • a paper-like pericarp containing a thickened, fleshy receptacle or hypanthium. (apple, pear, pomengranate)