Chlorophyta (Green Algae) - Week 8 - PDF

1 CHLOROPHYTA Green Algae  CHARACTERISTICS 2 qCovering of the cell: Cell wall. qCell wall composition: cellulose, pectin. qPigments: Chlorophyll a and b, b- carotene, xantophylls. qFood Reserve: Starch. qReproduction: Sexual - isogamy, anisogamy, oogamy; As...

1 CHLOROPHYTA Green Algae  CHARACTERISTICS 2 qCovering of the cell: Cell wall. qCell wall composition: cellulose, pectin. qPigments: Chlorophyll a and b, b- carotene, xantophylls. qFood Reserve: Starch. qReproduction: Sexual - isogamy, anisogamy, oogamy; Asexual – formation of akinetes, aplanospores and zoospores. qHabitat: Aquatic (fresh and marine); terrestrial. 3 ECONOMIC IMPORTANCE 4 qUsed as food and livestock meal. qSource of oxygen. qused in sewage treatment. qcrude oil in the sea bed qGenus Chlorella provide a good source of protein, fats, and carbohydrates.  5 CLASSIFICATION  CLASS 6 CHLOROPHYCEAE qUnicellular or multicellular. qMulticellular; qnever have transverse whorls of branches borne along a central filamentous axis differentiated into nodes and internodes. qIncludes 425 genera and 6,500 species.  ORDER VOLVOCALES 7 qVegetative cells: flagellated, motile. qSexual Reproduction: unicellular genera - division into definite number, colonial genera - colony divides to form daughter colony qAsexual Reproduction: isogamy, anisogamy, oogamy. 1. Family Chlamydomonadaceae Genus Chlamydomonas – chloroplast: cup-shaped. 2. Family Volvocales Genus Volvox CHLAMYDOMONAS 8 CHLAMYDOMONAS 9 LIFE CYCLE VOLVOX 10 ORDER ULOTRICHALES 11 qCells united end to end in simple or branched filaments. qThallus are differentiated into a prostate and erect portion. qAsexual Reproduction: formation of biflagellates or quadriflagellate zoospores. qSexual Reproduction: isogamy, heterogamy, oogamy. 1. Family Ulothrix Genus Ulothrix – filamentous; chloroplast: girdle-shaped. 2. Family Protococcaceae Genus Protococcus (Pleurococcus) ULOTHRIX 12 SPIROGYRA 13  14 PROTOCOCCUS (PLEUROCOCCUS)  ORDER CLADOPHORALES 15 qCells: multinucleate or coenocytic. qChloroplast: reticulated or netted with pyrenoids at intersections of the reticulum. qAsexual Reproduction: means of quadriflagellate zoospores, aplanospores, akinetes. qSexual Reproduction: isogamy, anisogamy. 1. Family Cladophoraceae Genus Cladophora Genus Pithophora CLADOPHORA 16  17 PITHOPHORA  ORDER 18 OEDOGONIALES qCells: cylindrical, uninucleate. qChloroplast: reticulate, extending from pole to pole with the cells encircling the protoplast. qSexual reproduction: oogamy. qAsexual Reproduction: zoospores formed singly within a cell but may be of akinetes. 1. Family Oededogoniaceae Genus Oedegonium – filamentous.  19 OEDOGONIUM  20 OEDOGONIUM LIFE HISTORY  ORDER ZYGNEMATALES 21 OR CONJUGALES qGametes are amoeboid and without flagella. qCells: solitary or united end to end in unbranched filaments. qCell wall: two layers, cellulose layer next to protoplast and outer layer of pectic materials. qSexual Reproduction: isogamy. 1. Family Zygnemateceae Genus Spirogyra (Water Silk or Pond Scum) Genus Zygnema 2. Family Desmidiaceae (co. Desmids) Genus Cosmarium Genus Closterium SPIROGYRA 22 The zygote develops into a filament of cells immediately after conjugation. 23 The zygote develops into only a single cell which later joins other cells to form a 24 filament.  25 ZYGNEMA  26 COSMARIUM CLOSTERIUM 27  ORDER 28 CHLOROCOCCALES qPrimary feature is the lack of vegetative cell. qAplanospores – non-flagellated spores having a definite wall distinct from the wall of a parent cell. qAutospore – an aplanospore having the same distinct shape as the parent cell. qSexual Reproduction: isogamy, anisogamy, oogamy.  29 1. Family Chroococcaceae 3. Family Hydrodictyaceae Genus Chlorococcum Genus Pediastrum 2. Family Oocystaceae Genus Hydrodictyon Genus Chlorella (Water Net) 4. Family Scenedesmaceae Genus Scenedesmus  30 CHLOROCOCCUM  31 CHLORELLA PEDIASTRUM 32  33 HYDRODICTYON SCENEDESMUS 34  35 MACROALGAE  36 ORDER SIPHONOCLADALES qHave thalli attached to the substratum by a system of rhizoids. qAsexual Reproduction: means of quadriflagellate zoospores. qSexual Reproduction: isogamy, maybe oogamy. 1. Family Valoniaceae Genus Valonia 2. Family Siphonocladaceae VALONIA 37  ORDER 38 DASYCLADALES qHave an erect central axis bearing whorls of branches from top to bottom or only at the upper end. qThalli have a single diploid nucleus. 1. Family Dasycladaceae Genus Acetabularia (Mermaid’s Wine Glass) Genus Halicoryne  39 ACETABULARIA 40 ACETABULARIA 41 LIFE HISTORY  42 HALICORYNE  43 ORDER ULVALES qHave parenchymatous thalli that maybe expanded sheets, hollow tubes or solid cylinders. qAsexual Reproduction: quadriflagellate zoospores. qSexual Reproduction: isogamy, heterogamy. 1. Family Ulvaceae Genus Ulva Genus Enteromorpha  44 ULVA Ulva lactuca Ulva reticulata  ULVA 45 LIFEHISTORY  46 ENTEROMORPHA  ORDER 47 SIPHONALES qThalli consist of a single multinucleate which is generally a branched tube capable of indefinite growth; thallus of certain genera is amorphous. qSexual Reproduction: isogamy, anisogamy, oogamy. 1. Family Caulerpaceae Genus Caulerpa 2. Family Codiaceae Genus Codium Genus Halimeda  48 CAULERPA Caulerpa serrulata Caulerpa racemosa  49 Caulerpa taxifolia Caulerpa lentilifera 50  51 HALIMEDA Halimeda tuna  52 CODIUM Codium edule  53 CLASS CHAROPHYCEAE qStoneworts. qHave erect branched thallus differentiated into regular succession of nodes ad internodes. qSexual Reproduction: oogamy. qOogonia are one-celled leaves. qAntheridia – one-celled united in branched filament of which several are surrounded by common spherical envelope composed of eight cells.  ORDER 54 CHARALES 1. Family Characeae Genus Chara q Color green because they possess more chlorophylls than carotenes and xanthophylls. q Produce underwater “meadows”. CHARA 55 56