Objectives for Lecture 16 Fungi Be able to state the characteristics of fungi Eukaryotic cells Multicellular and filamentous all are heterotrophs and absorb organic compounds as parasites or detritovores Have cell walls and wall contains chitin No motile cells and zygotic meiosis Crucial for cycling Carbon and Nitrogen they are also the most important cause of plant disease Know that fungi supply us with many important pharmaceuticals including penicillin which was the first widely used antibiotic Cyclosporin is derived from the soil fungus Tolypocladium It suppresses the immune reaction makes organ transplants possible Know the terms Hyphae fungal filaments Mycelium a mass of hyphae Chitin polymer of N acetylglucosamine same material found in the exoskeletons of arthropods Saprophyte same as detritivore Detritivore get nutrients by consuming detritus Parasite Be able to name the three groups of fungi and state their differences particularly those having to do with sexual reproduction Zygomycetes formation of spores within the zygosporangium Ascomycetes formation of spores in the ascus Basidiomycetes formation of spores within the basidium Know the following terms Zygomycetes major role as mycorrhiazae Stolons horizontal connections between plants Rhizoids thin filaments that help ancor and absorb nutrients Sporangia where spores are formed Gametangia where gametes are produced Zygosporangium gives rise to the sporangia Spores means o sexual reproduction Ascomycetes important plant pathogen spores formed in sexual reproduction in an ascus Conidia External asexual reproduction by means of multi nucleate spores Ascogonium female organ Antheridium formed by male nuclei Dikaryotic hyphae n n grow out of ascogonium to form a multicellular fruiting body ascocarp Ascocarp multicellular fruiting body Ascus plural asci Nuclear fusion Meiosis Ascospores Basidiomycetes decay organisms most mushrooms sexual reproduction by forming spores on basidium most have no asexual reproduction Monokaryotic hyphae monokaryotic hyphae fuse at their tips and dikaryotic hyphae grow out fruiting body Hyphal fusion Basiocarp structure on which the hymenium is produced Basidium plural basidia nuclear fusion formation of spores on basidium Meiosis haploid spores Basidiospores formed in the lining or the mushroom gills Know that fungi are important plant pathogens Know that yeasts are unicellular fungi that most yeast are ascomycetes in particular bakers yeast brewers yeast is an ascomycete Know that fungi certain Zygomycetes and Basidiomycetes for symbiotic associations with plant roots mycorrhizae Know that lichens are symbiotic associates between fungi usually Ascomycetes and a photosynthetic green alga or a Cyanobacterium Objectives for Lecture 17 Understand the difference between primary and secondary endosymbiosis and be able to state which of the algal groups we studied have chloroplasts that arose by primary or by secondary endosymbiosis Green algae and red algae are primary endosymbiosis The bulk of evidence indicates that all chloroplasts resulted from a single primary endosymbiotic event Diatoms dinoflagellates and brown algae are secondary endosymbiosis At least three separate secondary endosymbiotic events led to plastids in different groups of algae Know what phytoplankton are and what the biological and ecological importance is Phytoplankton produce about 30 of atmospheric O2 They are tiny photosynthetic organism suspended in the water column Base of food chain in open ocean Know what rides tides are what organisms cause them and what their environmental and health effects are When phytoplankton populations aren t held in check there can be red tides toxic blooms Not all red tides are red Some produce neurotoxins and can kill fish and paralytic shellfish poising in people Nori is a common use of alge However the red algae are also a source of agar capsules cosmetics culture medium gel electrophoresis baked goods and carrageenan stabilizes paints cosmetics and dairy products a clarifying agent in beer Be able to name the polysaccharides from red and brown algae that are economically important as emulsifying agents colloidal stabilizers and thickening agents The kelps brown algae Phylum Phaeophyta are a source of alginates Used as thickening agents colloid stabilizers in food textile cosmetic pharmaceutical paper and welding industries Understand the terms gametic meiosis zygotic meiosis alternation of generations gametophyte and sporophyte Gametic meiosis Type we are most familiar with only haploid gametes Zygotic meiosis haploid spore that can develop without fusion with another cell Alternation of generations Gametophyte is haploid gamete producing generations Sporophyte is the diploid spore producing generation For each of the groups of algae dinoflagellates diatoms brown algae and red algae know what their distinguishing characteristics are in terms of whether they are u nicellular or multicellular what their mode of nutrition is and what photosynthetic pigments they have what their cell wall is composed of where they are found fresh vs salt water whether they have flagella and what mode of sexual reproduction they use Dinoflagellates Unicellular and has 2 flagella Marine and fresh water photosynthetic and ingest food chlorophyll a and c carotenoids Cellulose in the cell wall Sexual reproduction is rare zygotic meiosis when it occurs Diatoms Unicellular no flagella Marine and freshwater photosynthetic with chlorophyll a and c carotenoids Silica cell wall most abundant of phytoplankton reproduction is mostly asexual but when sexual it is gametic meiosis Brown algae kelp Multicellular and photosynthetic with clorophyll a and c with carotenoids Found in cold marine waters Cell wall of cellulose and alginic acid Alternation of generations and gametic meiosis Red algae Most unicellular but a few are unicellular Tropical and cold marine waters some in fresh water No flagella photosynthetic with chlorophyll a and phycobillins Sexual reproduction with alternations of generations Cell wall contains cellulose agar and carrageenan Can grow at 200m depth Know what zooxanthellae are Some dinoflagellates zooxanthellae have lost their wall and occur as endosymbionts in sponges jellyfish sea anemones corals and other marine organisms They are primarily responsible for the photosynthetic productivity that makes possible the growth of coral reefs in nutrient poor tropical waters Know what the term heterokont
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