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Multicellular Algae. Characteristic 1 Live in/near water sources.
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Multicellular Algae Characteristic 1 • Live in/near water sources http://www.eplantscience.com/botanical_biotechnology_biology_chemistry/images/Plant%20organisms/Green_algae/Chlorophyta_large.jpg, http://www.californiasciencecenter.org/Exhibits/WorldOfEcology/ForestZone/KelpForest/images/Island-kelp-forest.jpg, http://upload.wikimedia.org/wikipedia/commons/2/29/Red_algae.jpg,
Multicellular Algae Characteristic 2 • Lack vascular tissue http://universe-review.ca/I10-24-vascular.jpg, http://en.es-static.us/upl/2012/03/seaweed.jpeg
Multicellular Algae Characteristic 3 • Some unicellular, some colonial, most multicellular http://www.microscopy-uk.org.uk/mag/imgdec03/volv3sm.jpg, http://www.marlin.ac.uk/imgs/o_ulvlac.jpg
Multicellular Algae Characteristic 4 • Reproductive cycles involve alternating sexual and asexual stages http://www.biologyjunction.com/images/chlamydomonasrepro.jpg
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 http://www.mrcorfe.com/KS4/Edexcel/Biology/B2-1-LivingCells/images/DiffusionCell.jpg
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 http://www.waterencyclopedia.com/images/wsci_01_img0122.jpg
Algal groups in phycology • According to: • Chlorophyll and accessory pigments • Form in which food is stored
Division Rhodophyta (Red algae) Chondruscrispus, Irish moss • 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 Lithothamnionglaciale http://www.biopix.nl/Temp/JCS%20Chondrus%20crispus%2015579.jpg, http://www.uwphoto.no/500/esv151cd221.jpg, http://media.treehugger.com/assets/images/2011/10/porphyra.jpg Porphyra nori
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 http://s1.hubimg.com/u/4873716_f260.jpg, http://www.ohio.edu/plantbio/vislab/algaeimage/jpegs/Sarg.JPG, http://www.deepseaimages.com/dsilibrary/data/683/22003_0208_125426aa_1_1.jpg Padina
Phaeophyta structures Thallus (pl. thalli) “sprout”- plantlike seaweed body • holdfast – attachment • stipe – stemlike support • blade – surface for photosynthesis • bladder – flotation, keeps blades near surface http://ez002.k12.sd.us/kelpai.jpg
SEXUAL Reproduction in Fucus Only multicellular part of the life cycle http://plantphys.info/organismal/lechtml/images/fucuslc.gif
DIvisionChlorophyta (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 http://www.ruf.rice.edu/~bioslabs/studies/invertebrates/invertimages/chlamy.gif, http://www.microscopy-uk.org.uk/mag/imgdec03/volvoxbirth2.jpg, http://www.aphotomarine.com/images/seaweed/green_seaweed_sea_lettuce_ulva_linza_17-03-09.jpg Ulva
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 http://universe-review.ca/I10-68-greenalgae1.jpg, http://silicasecchidisk.conncoll.edu/Pics/Other%20Algae/Green_jpegs/Chlamydomonas_Key100.jpg
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 http://protist.i.hosei.ac.jp/pdb/images/Chlorophyta/Gonium/sp_2a.jpg, http://anugrahjuni.files.wordpress.com/2010/02/oedogonium2.gif
multicellular green algae Ulva • Intertidal zone of marine habitats • Truly multicellular • 2-cells thick but tough http://2.bp.blogspot.com/_bQO5DdNy04g/S_3l_CGS8rI/AAAAAAAADgs/sCQ9cyg6lu0/s1600/i1023ulva.jpg
Reproduction in chlorophyta Haploid, N Alternation of generations • Diploid haploid stages • Asexual sexual modes of reproduction • Asexual spore* formation • Sexual gamete* formation * Both are haploid reproductive cells Diploid, 2N http://upload.wikimedia.org/wikipedia/commons/9/99/Haploid_vs_diploid.svg
Reproduction in chlamydomonas (unfavorable conditions) 2N N N N Dominant stage Fertilization/Syngamy Isogamy http://www.biologyjunction.com/images/chlamydomonasrepro.jpg
Reproduction in ulva Multicellular diploid stage with sporangia that produce spores N N 2N N Multicellular haploid stages with gametangia that produce gametes
“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 Undaria Porphyra Lithothamnium Chlorella Dunaliella Wakame Nori Ecology of Algae Laminaria Kombu