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Kingdom Monera

Kingdom Monera. What are PROKARYOTES ?. They are ancient life forms. known as bacteria. No nucleus. No chloroplasts. No mitochondria. Two major clades of bacteria. TEM of dividing cell. Archaebacteria. & Eubacteria. Cyanobacteria (Blue-green algae) & other. Methanogens

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Kingdom Monera

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  1. Kingdom Monera What are PROKARYOTES? They are ancient life forms known as bacteria • No nucleus • No chloroplasts • No mitochondria Two major clades of bacteria TEM of dividing cell Archaebacteria & Eubacteria Cyanobacteria (Blue-green algae) & other Methanogens Extreme Thermophiles Extreme Halophiles Gram negative bacteria Gram positive bacteria

  2. Prokaryotes Lack Organelles(w/ 2 membranes) • No nucleus but have DNA & RNA • No chloroplasts but have pigments, thylakoids & enzymes for PS • No mitochondria but have respiratory chain & membranes Other constituents? Gas vacuoles; • Small ribosomes (70S) for protein synthesis Cell walls; Storage molecules for N, P, C

  3. Geoclock Origin of life

  4. Cyanophytes establishedearly aerobic environments. Evolution of advanced aerobes 2 H2O + CO2 O2 + CH2O + H2O “Primordial ANAEROBIC soup”

  5. More conventional geologic time table

  6. Division Cyanophyta Bacteriathat are: • Photosynthetic (convert • light energy to food) • Produce O2 as a byproduct of photosynthesis • Some produce toxins TEM of dividing cell • Some have capacity to fix N2 into NH4 • Some have formed millions of years old • stromatolitesas living structures Cyanophytes have changed the path of evolution on earth

  7. Things we will cover General features - defining characteristics Developmental lineages – using morphology to understand evolution Ecology – understanding roles in interacting with other species Commercial interests – exploit ecology Evolution – diversity and change over time

  8. General features Habitats: virtually everywhere Ancient organisms but well suited to earth’s habitats Oceans Freshwater 2000 species, 150 genera Soil Hotsprings Epiphytes Endophytes Morphological Range: Unicells to complex multicell organisms Cell Walls: Gram negative bacteria Trichodesmium blooms can cover 2x106 km2 and be seen via satellites NASA

  9. Diversity

  10. Cell Walls Being comprised of only 20% peptidoglycan, the cell wall of Gram-negative bacteria is much thinner than Gram-positive bacteria. • Gram-negative bacteria have two unique regions which surround the outer plasma membrane: i) periplasmic space and ii) lipopolysaccharide layer. • periplasmic space separates the outer plasma membrane from the peptido-glycan layer. • lipopolysaccharide layer is adjacent to the exterior peptidoglycan layer

  11. Pigments - photosynthesis General features Storage Products Growth • Chlorophyll a • Phycobilins Phycoerythrin Phycocyanin Allophycocyanin Others • Carotenoids • UV absorbing molecules

  12. Photosynthesis & Pigments sunlight • Light energy is harvested • by the cell • Only specific colors are absorbed Cell • Other colors are reflected back to your eye thylakoids Chl a Chl a Phycobilins

  13. Chlorophyll a Tetrapyrrole Ring Phytol Chain

  14. Phycobilins Open tetrapyrrole phycoerythrin phycocyanin

  15. Photosynthesis & Pigments • Arrangement of light • harvesting structure is • specific and detailed Chlorophyll a

  16. Pigments - photosynthesis General features Storage Products Growth • Chlorophyll a • Starch (C) • Phycobilins • Cyanophycin (N) Phycoerythrin • Poly Pi bodies Phycocyanin Allophycocyanin Others • Carotenoids • UV absorbing molecules

  17. Storage products Starch C = black O = red H = white C = green = blue H = red = white P = purple ATP

  18. General features What is in a typical cyanophyte cell? DNA & RNA Pigments, thylakoids & enzymes for PS Respiratory chain & membranes Small ribosomes (70S) Cell walls ? Storage molecules for N, P, C ? Floatation?

  19. Pigments - photosynthesis General features Storage Products Growth • Every cell can  • Multicellular organisms: • Chlorophyll a • Starch (C) • Phycobilins • Cyanophycin (N) Fragments regrow Phycoerythrin • Poly Pi bodies “Spores”regrow Phycocyanin Akinetes germinate Allophycocyanin • Branching Others True branching • Carotenoids False branching • UV absorbing molecules

  20. Growth & morphology 1   1     Binary Fission (cell division) 8 16 cells 1   1 1 4 2 Cell division for unicells: Produces genetically identical “offspring” or twins Increases the numbers of cells in the population by exponential growth, 2n Divisions may be every 15 to 20 min

  21. Growth & morphology Unicell populations grow rapidly Cyanotech ponds Starting with 1 cell: 10 rounds of division  1,000+ cells It’s not unusual to have 10 6 to 108 cells / mL in “blooms”

  22. Developmental lineages Evaluate adult form to gain insight in possible evolutionary processes. Step-by-step acquisition of new traits via genetic change. Examine reproductive cells and other characters as additional data. Useful means to construct evolutionary hypotheses to test with molecular data.

  23. Growth & morphology Developmental Lineage #1 Order Chroococcales Genetic change All cells appear virtually identical - internally Evolution has taken a simple shape to more complex but related forms: • Multicellular genera

  24. Diversity Order Chroococcales Microcystis Merismopedia

  25. Growth & morphology 1 colony Coordinated binary fission of all cells in colony   2 colonies Multicellular organisms divide but increase the number of entities in the population

  26. Growth & morphology Developmental Lineage #2 Order Chamaesiphonales Evolution has taken a simple shape: • attachment to the substrate • spores released from upper end of cell

  27. Growth & morphology Developmental Lineage #3 Order Nostocales trichome + sheath (filament) trichome (no sheath evident) Evolution has taken a simple shape: • constrained cells into chains • formed arrays of trichome(s) in sheaths trichomes + sheath • false branching can result

  28. Diversity Order Nostocales

  29. Growth & morphology Order Nostocales False branching : 1. Rupture of sheath and cells 2. Remaining cells at both ends continue to grow 3. Both trichomes push through weakened sheath What to look for? Is there a change in the plane of cell division?

  30. New Cell Types Order Nostocales polar heterocysts Nitrogen fixation supports protein synthesis 1. Low N in environment 2. Cell differentiates as a specialized cell, the heterocyst 3. Creates setting for Nitrogenase enzyme 4. Enzyme converts N2 NH4+

  31. Growth & morphology Order Nostocales Nitrogen fixation & Azolla in rice fields replace fertilizers 1. Low N in environment 2. Heterocysts differentiate 3. Enzyme converts N2 NH4+ 4. Water fern benefits from fertilizer 5. Rice fields are more productive intercalary heterocysts

  32. Other cell types Order Nostocales Akinete Anabaena

  33. Cool stuff Order Nostocales

  34. Growth & morphology Developmental Lineage #4 Order Stigonematales True branching Evolution has taken a simple shape: • formed arrays of cells that divide in 2 directions (planes) Multiseriate tissues

  35. Growth & morphology Order Stigonematales True branching : 1. No rupture of sheath or cells 2. Cells divide in two planes 3. Create new structures, branches What to look for? Is there a change in the plane of cell division?

  36. Growth & morphology Order Stigonematales Complex tissue • Multicellular • Organized multiseriate layers • Cell dimorphism

  37. Vocabulary prokaryote eukaryote binary fission nucleus thylakoid chloroplast phycobilins mitochondrion phycobilisome accessory pigment akinete heterocyst multiseriate uniseriate trichome sheath false branching true branching nitrogenase photosynthesis Azolla Lyngbya Anabaena Stigonema

  38. Who am I?

  39. Reading & Viewing Scientific American Extremophiles: http://www.spaceref.com/redirect.html?id=0&url=www.sciam.com/0497issue/0497marrs.html National Geographic: http://www.nationalgeographic.com/world/0010/bacteria/bacteria.html An underworld of hydrogen sulfide harbors life-forms awesome and awful: http://www.nationalgeographic.com/ngm/0105/feature4/index.html NASA interactive page http://nai.arc.nasa.gov/_global/shockwave/g3_matgallery.swf Powers of ten interactive page: http://microscopy.fsu.edu/primer/java/scienceopticsu/powersof10/index.html Mereschowsky, C., (1905). Über Natur und Ursprung der Chromatophoren im Pflanzenreiche., Biol. Centr. 25, 593-604 & 689-691. Mereschowsky, C., (1910). Theorie der zwei Plasmaarten als Grundlage der Symbiogenesis, einer neuen Lehre von der Entstehung der Organismen., Biol. Centr. 30, 353-367, 1910. Margulis, L. (1970). Origin of eukaryotic cells. Yale University Press, New Haven.

  40. Picture credits http://www.nhm.uio.no/palmus/galleri/montre/english/gruppe_liste_e.htm http://astrobiology.arc.nasa.gov/roadmap/goals/index.html http://www.lalanet.gr.jp/nsm/E-stromatolite.html http://www.petrifiedseagardens.org/main.htm Saratoga Springs NY http://www.rockhounds.com/grand_hikes/hikes/stromatolites_in_the_hakatai/ http://www.ngdc.noaa.gov/mgg/sepm/palaios/9810/knoll.html

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