1. Explain the 4 requirements of a gene for phylogenetic studies and give an example of a gene or genes that meet all these criteria
    • Be present in all organisms of interest
    • Not laterally transferred between species
    • Well conserved but still have changes
    • Sufficiently large to provide enough information
    • rRNAs meet these criteria (16S and 23S commonly used)
  2. Differentiate between a cladogram and a dichotomous key and applications of each
    • Cladogram: a chart that shows relationships between organisms (that they share a common ancestor)
    • Dichotomous key: organized set of mutually exclusive characteristics of organisms that can be used to determine which organism and unknown is
  3. Define taxonomy
    The science of classifying organisms
  4. Give two reasons why organisms are arranged in taxonomic groups
    • Classification: puts organisms into groups based on degree of relatedness
    • Nomenclature: provides universal names for organisms
    • Identification: provides a reference for identifying organisms
  5. List the three domains; give the characteristics of each, and the kinds of organisms found in each
    • Bacteria: prokaryotic, peptidoglycan in cell walls
    • Archaea: prokaryotic, no peptidoglycan in cell walls, extremophiles
    • Eukarya: eukaryotic, cell wall varies (animalia, fungi, plantae, protista)
  6. Define binomial nomenclature, explain the importance of scientific names and give examples of bacterial names
    • Genus + specific epithet
    • Used worldwide, identical no matter where you are
    • Escherichia coli, staphylococcus aureus
  7. Give the order of taxonomic groups from the most general to the most specific (current taxonomic hierarchy)
    Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
  8. List the 4 eukarya kingdoms, list characteristics used to differentiate among them, and give examples from each
    • Animalia: multicellular, heterotrophic, no cell walls (sponges, worms, insects, vertebrates)
    • Plantae: multicellular, cellulose cell walls, usually photoautotrophic (algae, mosses, ferns, confiers, flowering plants)
    • Fungi: chemoheterotrophic, unicellular OR multicellular, cell walls of chitin, develop from spores
    • Protistsa: catchall for eukaryotic organisms that do not fit into other kingdoms (slime molds, algae, protozoa)
  9. Define: genus, species (bacterial species), strain, clone
    • Genus: Set of closely related species
    • species: population of cells with similar characteristics
    • Clone: population of cells derived from a single cell
    • Strain: genetically different cells within a clone
  10. List and discuss the methods of classifying and identifying microorganisms
    • Morphological characteristics
    • differential staining
    • biochemical tests
    • serology (antiserum+bacterium)
    • phage typing (using viruses)
    • DNA base composition
    • DNA fingerprinting (gel electrophoresis)
    • rRNA sequencing
  11. Describe the basis of chemical tests, serology, and phage typing
    • Chemical tests: determines enzymatic activites, tests for presence or absence of a specific enzyme, selective and differential media
    • Serology: combines known antiserum with unknown bacteria (slide agglutination, Enzyme-linked immunosorbent assay - contains enzyme substrate, and Western blot - uses antibodies)
    • Phage typing: uses viruses to identify bacteria (viruses are hyper specific)
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