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Published byCecil McBride Modified over 6 years ago
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Kingdom Plantae Multicellular Algae Nonvascular Plants Vascular Plants
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Multicellular Algae Characteristic 1 Live in/near water sources
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Multicellular Algae Characteristic 2 Lack vascular tissue
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Multicellular Algae Characteristic 3
Some unicellular, some colonial, most multicellular
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Multicellular Algae Characteristic 4
Reproductive cycles involve alternating sexual and asexual stages
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Multicellular Algae Characteristic 5 Well-adapted to life in water
Thin leaf-like structures (~2 cells thick) Movement of materials into the organism is through diffusion No stems Ease of sexual reproduction
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Multicellular Algae Characteristic 6
Adapted to life in the intertidal zone Cell wall of cellulose and gel-like sugar (slimy and rubbery) Some have CaCO3
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Algal groups in phycology
According to: Chlorophyll and accessory pigments Form in which food is stored Multicellular Algae Division Rhodophyta Division Phaeophyta Division Chlorophyta
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Division Rhodophyta (Red algae)
Habitat Some freshwater, most marine Polar regions, tropics Up to ~260 m depth Pigments Chl a (all) phycoerythrin absorbs blue light appears green, pink, red, purple, black Food reserve: Floridean starch Mostly multicellular; no flagella and centrioles Chondrus crispus, Irish moss Lithothamnion glaciale Porphyra nori
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Division Phaeophyta (Brown algae)
Habitat Mostly marine Cool, shallow coastal waters of temperate/arctic areas Pigments Chl a and c fucoxanthin Dusky olive/yellow-brown Food reserve: laminarin All multicellular; largest and most complex algae Macrocystis pyrifera, giant kelp Padina
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Phaeophyta structures
Thallus (pl. thalli) “sprout”- plantlike seaweed body holdfast – attachment stipe – stemlike support blade – surface for photosynthesis bladder – flotation, keeps blades near surface
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SEXUAL Reproduction in Fucus
Only multicellular part of the life cycle
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DIvision Chlorophyta (green algae)
Habitat: Freshwater/marine/moist areas Pigments: Chl a and b, carotenoids Food reserve: starch Cell wall of cellulose Unicellular/colonial/multicellular Ancestors of modern land plants Volvox Ulva
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Unicellular green alga
Chlamydomonas Ponds, ditches 2 flagella Cup-shaped chloroplast Pyrenoid at base synthesizes and stores starch 2 small contractile vacuoles Eyespot Cell wall not made of cellulose
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colonial green algae Gonium
4-42 identical cells living together but functioning independently Volvox 500-50,000 cells arranged in hollow spheres Most cells identical; few produce gametes Oedogonium Threadlike colonies Holdfast cell attached to lake/pond bottom Asexual reproduction: broken filaments divide and grow Sexual reproduction: formation of gametes
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multicellular green algae
Ulva Intertidal zone of marine habitats Truly multicellular 2-cells thick but tough
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Reproduction in chlorophyta
Alternation of generations Diploid haploid stages Asexual sexual modes of reproduction Asexual spore* formation Sexual gamete* formation * Both are haploid reproductive cells Haploid, N Diploid, 2N
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Reproduction in chlamydomonas
(unfavorable conditions) 2N N N N Dominant stage Fertilization/Syngamy Isogamy
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Reproduction in ulva Multicellular haploid stages with
Multicellular diploid stage with sporangia that produce spores N N 2N N Multicellular haploid stages with gametangia that produce gametes
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Ecology of Algae “grasses of the sea” home to marine organisms
source of oxygen source of pharmaceuticals food products algin from brown algae carageenan and agar from red algae non-food products Chlorella Dunaliella Lithothamnium Laminaria Porphyra Nori Undaria Wakame Kombu
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