Biological Diversity BSCI 10110 1 MWRF 1 10 2 00 Dr Mark Kershner Week 7 10 12 Exam 2 Friday 10 16 Chapters 22 23 26 27 and 28 everything through the end of Wednesday Review Session Wednesday 10 14 4 6 in Bowman 207 Domain Bacteria gram staining cell wall composition indicates resistance to environment recognizing nutrients and other organisms gram positive bacteria thick cell wall major component is peptidoglycan staining colors pepticoglycan layer purple Fig 28 8 gram negative bacteria 2 layers in cell wall thin sheet of peptidoglycan outer layer that is a lipid bilayer membrane lipopolysaccharides porin recognition of toxins food other organisms creates barrier that inhibits prevents certain molecules from getting in much less susceptible to antibiotics porin protein regulating cell entry prevents coloring of peptidoglycan layer another dye is added pink cells Gram positive bacteria Actinobacteria soil bacteria form nodules on plant roots ex alfalfa bean alder tree full of bacteria symbiotes both plant and bacteria gain advantage nodules gaining access to structure nutrients C plant N fixation N2 NH4 ammonia nodule N2 NH4 made available to plant increased growth increased production common dental plaque biofilm community of bacteria fungi algae viruses complex structure side of tooth early colonizers minimum of ten species late colonizers form on top of early colonizers toxins many produce antibiotics streptomycin tetracycline produce anti fungal very expensive energetically for bacteria to make protects them from fungi bacteria growth increases no competition for food limiting resource they produce spores resting stage during drought Arthrobacter allows them to handle difficult environmental conditions gain energy from lots of substrates break down toxins heavy metals soil contaminants bioremediation Hexavalent chromium Erin Brockovich treated by an Arthrobacter Frankia nodule forming bacteria Mycobacterium bovis bovine tuberculosis Streptomyces good and some very bad species streptomycin Bacillus thuringiensis Bt insecticidal bacterium biocontrol bacterium dehydrate endospore and crystal gypsy moths agricultural pests black flies on plants Eurasian corn borer feeds on leaves ingests Bt spore and crystal spore will develop into bacteria crystal dissolves releases protein binds to the gut wall toxic eats holes into gut wall reduces digestion starve to death paralyzed death 10 14 Bt review corn borers Bt crystals using genetic engineering incorporated the cry gene responsible for go toxic when they are digested cry toxin bonds to the gut wall toxin into plant genome present in all tissues cry toxin bonds to the gut wall mortality corn cotton beans alfalfa peanut plants presence of cry toxin in crops evolutionary pressure could select for resistant individuals must reproduce Diamondback moth already shows resistance Bacillus anthracis anthrax oldest known grazing animal disease global in soil long lived endospores agricultural areas three major forms inhalation of spores nearly always fatal cutaneous living bacterial cells gastrointestinal ingestion of spores it takes a significant number of spores for a significant infection approximately twenty thousand spores needed Streptococcus Staphylococcus common on human skin opportunistic pathogens Strep Staph pneumonia rheumatic scarlet fever tooth decay respiratory skin blood digestive sinus infections Streptococcus pneumoniae pneumococcal meningitis Streptomyces orientalis produces Vancomycin antibiotic used to treat Streps MRSA MRSA methicillin resistant Staphylococcus aureus End for Exam 2 Gram negative bacteria Spirochaete morphology helical coiled cells Ex Treponema syphilis common in aquatic environments Borrelia burgdorferi Lyme disease deer ticks 10 15 Sympatric speciation no geographical isolation can begin occur very quickly Mamavirus infects Acanthamoeba largest viruses have virus factories negative effects on Acanthamoeba growth reproductive output researcher noted different particles determined that they were a separate virus type virophage virophage kills mamavirus limiting reproduction infecting viruses bacteriophage infecting bacteria benefits the protest increases survival increases reproduction Phagocytosis mode of feeding used by many unicellular organisms sputnik endosymbiosis Hawthorn Fly Rhagoletis adults live on hawthorns dance ritual mating successful reproduction eggs are laid hatch feed on hawthorn metamorphose orchards adults move from hawthorns apple trees unicellular eukaryotic organisms eat bacteria particles through phagocytosis forms a vacuole around bacteria particles enzymes digest item products of digestion used by organism for energy Lytic cycle and lysogenic cycle Fig 27 5 Flagellum prokaryote corkscrew motion single protein filament eukaryote whip like locomotion foraging 9 2 arrangement
View Full Document
Unlocking...