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Alpha- proteobacteria

Alpha- proteobacteria. Rhizobium f orms symbiotic root nodules w/legumes ( Fabaceae ). Agrobacterium Ti plasmid used for plant genetic engineering. Gamma- proteobacteria. Salmonella c atalase-positive t yphoid, food poisoning

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Alpha- proteobacteria

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  1. Alpha-proteobacteria • Rhizobium • forms symbiotic root nodules w/legumes (Fabaceae) • Agrobacterium • Ti plasmid used for plant genetic engineering

  2. Gamma-proteobacteria • Salmonella • catalase-positive • typhoid, food poisoning • most subspecies produce hydrogen sulfide as a metabolic byproduct • Escherichia • E. coli model organism • catalase-positive

  3. Gram-positives • Bacillus • endospore-forming • catalase-positive • anthrax • B. subtilis model organism • Streptomyces • originated many antibiotics (streptomycin, tetracycline, chloramphenicol) • high-GC genomes

  4. Others • Anabaena • cyanobacterium • heterocysts engage in nitrogen fixation • symbiotic relationship with Azollafern (functionally similar to Rhizobium+legumes) • Thermus • T. aquaticusDNA polymerase used in PCR

  5. Archaea • Similar to Eukarya: • histone-associated DNA • translation initiated with methionine • Similar to Bacteria: • external morphology • circular genome • operons, polycistronic mRNA • no introns/RNA processing

  6. Examples • Methanobacterium • type of methanogens (methanogens are not monophyletic) • obligately anaerobic • reduce CO2 to CH4 using H2 • Halobacterium • aerobic • high-salt environments (protein function) • uses bacteriorhodopsin as proton pump for ATP generation • Thermoplasma • high-temperature acidophiles • facultative anaerobes (can respire using sulfur in anaerobic conditions) • no cell walls • Sulfolobus • high-temperature acidophiles • can grow lithoautotrophically by oxidizing sulfur to sulfates • chemoheterotrophs by using sulfur to oxidize carbon compounds

  7. Euglenozoa – Euglenids • possess chloroplasts through secondary endosymbiosis of green algae (thus their chloroplasts have three membranes) • no cell wall, but pellicle made of protein • pyrenoids store paramylon (carbohydrate similar to starch) • Euglena

  8. Euglenozoa – Kinetoplastids • all possess a kinetoplast: dense DNA granule within mitochondrion, located at the cell’s basal body • Trypanosoma • obligate, heteroxenous parasites • T. cruzi– Chagas’ disease • T. brucei – African sleeping sickness

  9. Stramenopiles – Phaeophyta • brown algae • all multicellular • possess xanthophyll called fucoxanthin, giving distinctive color • body called a thallus • holdfast “root” • stipe “stem” • pneumatocysts provide buoyancy • Sargassum • oogamous, diploid body

  10. Stramenopiles – Bacillariophyta • diatoms • enclosed in silicon-based cell wall called a frustule • sexual reproduction involves formation of an auxospore • four-membraned chloroplasts (characteristic of all stramenopiles) • Diatoma

  11. Alveolates – Apicomplexa • intracellular animal parasites w/ complex life cycles • apicoplast: four-membraned plastid involved in host cell penetration • generally sporozoites infect a host, replicating in cells to produce merozoites which infect other cells • Plasmodium

  12. Alveolates – Ciliates • possess a diploid micronucleus (for reproduction) and polyploid macronucleus (for transcription) • asexual reproduction occurs via binary fission • conjugation: micronuclei undergo meiosis and haploid micronuclei are exchanged over the mating bridge • organelles called trichocysts that release hairs in response to stimuli

  13. Alveolates - Dinoflagellates • characterized by 2 flagella, one transverse and one longitudinal • lack histones, nucleosomes • haploid • most possess a dinokaryon nucleus • DNA condensed throughout interphase • nuclear membrane does not break down • mitotic spindle is extranuclear • Ceratium

  14. Rhodophyta • red algae • color due to phycoerythrin pigment • carbohydrate stored as floridean starch, more highly branched than amylopectin • many exhibit complex alternation of generations with 2 sporophyte generations • Chondrus

  15. Amoebozoa - Lobosea • Unikonts (previous protists were dikonts) • Amoeba • endoplasm/ectoplasm: differential flow of cytoplasm causes movement • actin-based pseudopodia appendages

  16. Amoebozoa – Eumycetozoa • Slime molds • Myxogastria: • plasmodial slime molds • single-celled, haploid myxamoebas/myxoflagellates • extended diploid multinucleate reproductive form called plasmodium • Dictyostelia: • cellular slime molds • single-celled and mononucleate haploids • aggregate into multiorganismic “pseudoplasmodium” (still haploid) • sexual reproduction involves macrocyst formation • Dictyostelium

  17. Zygomycota • characterized by zygosporangium, a resistant diploid reproductive structure • cell walls made of chitosan, deacetylated chitin • Mucor

  18. Ascomycota • sexual reproduction involves formation of asci in an ascocarp • each ascus has eight ascospores • tissue layer containing asci: hymenium • apothecium: hymenium open outward • cleistothecium: hymenium closed, bursts open • perithecium: hymenium closed off except for a single pore • most lichens have ascomycetemycobionts • Penicillum • Saccharomyces • no ascocarps, naked asci • Clavicepscauses ergot infections

  19. Basidiomycota • Long heterokaryotic stage • Clamp connections to coordinate division of dikaryotic nuclei • Form basidia containing basidiospores, which germinate into haploid mycelia • Agaricus • Rusts: • obligate parasites, many requiring more than one host • complex life cycle w/ up to 5 different spore types • Puccinia

  20. Animals • Porifera • eukaryotic, multicellular • heterotrophic • no cell walls

  21. Porifera • water flows through ostia out to osculum • flagellated choanocytes collect food • asconoid, synocoid, leuconoid structures • Spongia

  22. Animals • Porifera • Cnidaria • Anthozoa • Scyphozoa • Hydrozoa • Ctenophora • true tissues • germ layers

  23. Cnidaria

  24. Ctenophora • Two-cell layer surrounding mesoglea (one-cell thick in Cnidaria) • swim using combs of cilia • no cnidocytes; instead colloblasts release adhesive substance • Mertensia

  25. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Protostomia • Platyhelminthes • Lophotrochozoa • Ecdysozoa • triploblastic body • bilateral symmetry • schizocoelous development • spiral, determinate cleavage

  26. Platyhelminthes • Turbellaria: • paraphyletic, all free-living flatworms • Pseudoceros • Cestoda: • strictly sexual reproduction • Echinococcus • Trematoda: • heteroxenous parasites (mollusk + vertebrate) • Schistosoma

  27. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Protostomia • Platyhelminthes • Lophotrochozoa • Mollusca • Annelida • Ecdysozoa • Trochophores: produce trochophore larvae (with two bands of cilia around middle) • Lophophore: band of tentacles around mouth • closed digestive systems • coeloms

  28. Lophotrochozoa – Mollusca • Gastropoda: • Arion(slugs) • Achatina(snails) • Cephalopoda: • Nautilus • Sepia (cuttlefish) • Bivalvia: • Pinctada(pearl oysters)

  29. Lophotrochozoa – Annelida • Polychaeta: • parapodia serve as gas exchange • protostomium equipped with palps, nuchal organs, eyes, antennae • Nereis • Oligochaeta: • no parapodia • prostomium not well-developed • Lumbricus • Hirudo(leech)

  30. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Protostomia • Platyhelminthes • Lophotrochozoa • Mollusca • Annelida • Ecdysozoa • Nematoda • Arthropoda • periodically shedding cuticle

  31. Ecdysozoa – Nematoda • pseudocoelomates • Caenorhabditis

  32. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Protostomia • Deuterostomia • Echinodermata • Asteroidea • Holothuroidea • Echinonoidea • Chordata • triploblastic body • bilateral symmetry • enterocoelous development • radial, indeterminate cleavage

  33. Echinodermata • Asteroidea: • Linckia • Echinoidea: • Diaderna • Holothuroidea: • Holothuria

  34. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Protostomia • Deuterostomia • Echinodermata • Chordata • Urochordata • Cephalochordata • Vertebrata • notochord • dorsal nerve cord • pharyngeal slits • post-anal tail

  35. Urochordata (Tunicata) • some are sessile; others are free-floating • filter feeders, with incurrent + excurrent siphon • Ascidia

  36. Cephalochordata • lancelets • notochord persisting throughout life • filter-feeders, usually half buried in sediment • Branchiostoma

  37. Animals • Porifera • Cnidaria • Ctenophora • Bilateria • Deuterostomia • Chordata • Vertebrata • Hyperoartia • Gnathostomata • cephalization • vertebral column • doubling of Hox clusters (lancelets, tunicates have only one set) • neural crest

  38. Hyperoartia • parasitic or filter-feeders • Petromyzon

  39. Animals • Deuterostomia • Chordata • Vertebrata • Gnathostomata • Chondrichthyes • Osteichthyes • jaws (developed from first gill arch) • another doubling of Hox clusters (now there are four) • lateral lines

  40. Chondrichthyes • contain Leydig’s organ, involved in erythropoiesis • skin is covered in denticles • Carcharodon(great white) • Dasyatis(stingrays) • Apristurus(catshark)

  41. Animals • Deuterostomia • Chordata • Vertebrata • Gnathostomata • Osteichthyes • Actinopterygii • Sarcopterygii • lungs (swim bladders) • one dorsal fin

  42. Actinopterygii • fin rays (fins supported by bony spines) • Carabus(sturgeons) • Barbus(barbell) • Anguilla (freshwater eels) • Salmo (salmon)

  43. Animals • Vertebrata • Gnathostomata • Osteichthyes • Sarcopterygii • Dipnoi • Coelocanthomorpha • Tetrapoda • bony fins surrounded by muscle • two dorsal fins • teeth with true enamel

  44. Coelocanthomorpha, Dipnoi • Coelocanthomorpha: • Latimeria • Dipnoi: • true lungs (homologous to land animal lungs) • almost all obligate air breathers • Protopterus

  45. Animals • Vertebrata • Gnathostomata • Osteichthyes • Sarcopterygii • Tetrapoda • Amphibia • Amniota • four limbs evolved from fins • head separated from neck by vertebrae

  46. Amphibia • Caudata (salamanders): • possess tail • aposematism • Salamandra • Anura (frogs) • no tail • Rana(pond frogs, bullfrogs)

  47. Animals • Vertebrata • Gnathostomata • Osteichthyes • Sarcopterygii • Tetrapoda • Amniota • Reptilia • Mammalia • terrestrially adapted egg w/ four membranes • larval stage

  48. “Reptilia” • Testudines (Chelonia, tortoises) • Testudo • Squamata (lizards, snakes) • movable quadrate bone • Gekko, Python • Crocodyliomorpha • Crocodylus • Aves…

  49. Aves • Paleognathae: • most basal birds • mainly flightless • Struthio(ostrich) • Galloanserae: • fowl/waterfowl • Gallus (chicken) • Neoaves: • all other birds (more derived) • Columba (dove) • Passer (sparrow) • Apus(swift) • Dendrocopos(woodpeckers)

  50. Animals • Vertebrata • Gnathostomata • Osteichthyes • Sarcopterygii • Tetrapoda • Amniota • Mammalia • mammary glands for feeding young • middle ear bones (incus, malleus, stapes) • hair • neocortex

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