archive-edu.com » EDU » B » BERKELEY.EDU

Total: 975

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".

  • WBS 8 22 97 Reviewed by Anne Weil

    Original URL path: http://www.ucmp.berkeley.edu/geology/tectonicsau.html (2012-11-11)
    Open archived version from archive


  • Fossil Record of the Bacteria
    Chert of northern Australia about 1 billion years old Very similar cyanobacteria are alive today in fact most fossil cyanobacteria can almost be referred to living genera Compare this fossil cyanobacterium with this picture of the living cyanobacterium Oscillatoria The group shows what is probably the most extreme conservatism of morphology of any organisms Aside from cyanobacteria identifiable fossil bacteria are not particularly widespread However under certain chemical conditions bacterial cells can be replaced with minerals notably pyrite or siderite iron carbonate forming replicas of the once living cells or pseudomorphs Some bacteria secrete iron coated sheaths that sometimes fossilize Others may bore into shells or rocks and form microscopic canals within the shell such bacteria are referred to as endolithic and their borings can be recognized all through the Phanerozoic Bacteria have also been found in amber fossilized tree resin and in mummified tissues It is also sometimes possible to infer the presence of disease causing bacteria from fossil bones that show signs of having been infected when the animal was alive Perhaps most amazing are the fossils left by magnetobacteria a group of bacteria which form tiny nanometer sized crystals of magnetite iron oxide inside their cells Magnetite

    Original URL path: http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html (2012-11-11)
    Open archived version from archive

  • Life History and Ecology of Bacteria
    and existence Other bacteria are anaerobic and cannot tolerate gaseous oxygen such as those bacteria which live in deep underwater sediments or those which cause bacterial food poisoning The third group are the facultative anaerobes which prefer growing in the presence of oxygen but can continue to grow without it Bacteria may also be classified both by the mode by which they obtain their energy Classified by the source of their energy bacteria fall into two categories heterotrophs and autotrophs Heterotrophs derive energy from breaking down complex organic compounds that they must take in from the environment this includes saprobic bacteria found in decaying material as well as those that rely on fermentation or respiration The other group the autotrophs fix carbon dioxide to make their own food source this may be fueled by light energy photoautotrophic or by oxidation of nitrogen sulfur or other elements chemoautotrophic While chemoautotrophs are uncommon photoautotrophs are common and quite diverse They include the cyanobacteria green sulfur bacteria purple sulfur bacteria and purple nonsulfur bacteria The sulfur bacteria are particularly interesting since they use hydrogen sulfide as hydrogen donor instead of water like most other photosynthetic organisms including cyanobacteria Bacteria play important roles in the global ecosystem The ecosystem both on land and in the water depends heavily upon the activity of bacteria The cycling of nutrients such as carbon nitrogen and sulfur is completed by their ceaseless labor Organic carbon in the form of dead and rotting organisms would quickly deplete the carbon dioxide in the atmosphere if not for the activity of decomposers This may not sound too bad to you but realize that without carbon dioxide there would be no photosynthesis in plants and no food When organisms die the carbon contained in their tissues becomes unavailble for most other living

    Original URL path: http://www.ucmp.berkeley.edu/bacteria/bacterialh.html (2012-11-11)
    Open archived version from archive

  • Systematics of the Bacteria
    small and have simple shapes though there are some bacteria notably the cyanobacteria and actinomycetes with sufficiently complex morphology to permit classification by shape In addition to shape bacteria have traditionally been identified and classified on the basis of their biochemistry and the conditions under which they grow The advent of molecular biology has made it possible to classify bacteria on the basis of similarities among DNA sequences and has

    Original URL path: http://www.ucmp.berkeley.edu/bacteria/bacteriasy.html (2012-11-11)
    Open archived version from archive


  • bmw 3 1 95 8 18 95 Touching up 10 15 96 brs 06 28 95 8 14 95

    Original URL path: http://www.ucmp.berkeley.edu/bacteria/aubacteria.html (2012-11-11)
    Open archived version from archive

  • Copyright Statement
    on this Web Server UCMP1 BERKELEY EDU may not be reproduced or stored in a retrieval system without prior written permission of the publisher except for educational purposes and in no case for profit Photomicrograph of Mycobacterium provided by Brian Meehan and Dr Sidney Neil Dept of Veterinary Science the Queen s University of Belfast Photomicrograph of Leptospira provided by Brian Meehan and Prof William A Ellis Dept of Veterinary

    Original URL path: http://www.ucmp.berkeley.edu/bacteria/baccopyright.html (2012-11-11)
    Open archived version from archive

  • Menu for /alllife/eukcollage.map
    ucmp berkeley edu images unmapped gif http www ucmp berkeley edu alllife eukaryotasy html http www ucmp berkeley edu plants plantae html http www ucmp berkeley edu fungi fungi html

    Original URL path: http://www.ucmp.berkeley.edu/alllife/eukcollage.map (2012-11-11)
    Open archived version from archive

  • Fossil Record of the Eukaryota
    stages in eukaryote evolution will fit so here goes Eukaryotes are defined by the presence of a nucleus Hence there was much excitement when these microfossils were found in the 1 billion year old Bitter Springs Formation of northern Australia and similar microfossils were found in even older rocks About 5 micrometers across these spherical fossils seem to have preserved nuclei This interpretation is now doubted it s more likely

    Original URL path: http://www.ucmp.berkeley.edu/alllife/eukaryotafr.html (2012-11-11)
    Open archived version from archive