Micro-Biology FInal

Cards (97)

  • The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is
    inoculation
  • A nutrient medium that contains at least one ingredient that is NOT chemically definable would be termed
    complex
  • Which type of medium is able to distinguish different species or types of microorganisms based on an observable change (e.g. color) in the colonies or in the medium?
    differential
  • If a microbiologist is studying a specimen at a total magnification of 950x, what is the magnifying power of the objective lens if the ocular lens is 10x?
    95x
  • Which type of microscope achieves the greatest resolution and highest magnification?
    Electron
  • The purpose of staining cells on a microscope slide is to
    add contrast in order to see them better
  • Basic dyes are
    positive charged attracted to the negatively charged substances (e.g. membranes) of bacterial cells
  • The Gram staining procedure is best described as a(n) _______ staining technique.
    differential
  • A selective medium contains one or more substances that inhibit growth of certain microbes in order to facilitate the growth of other microbes.
    true
  • Steps for gram staining
    1. Crystal violet is the primary stain both gram negative and gram positive are both purple.
    2. Iodine is the mordent which makes the bacteria stain still both grams are purple.
    3. Alcohol is the decolorizer which make gram negative clear and gram positive still purple
    4. Safranin is the counterstain which make the gram negative stain pink and gram positive purple still
  • The bending of light rays as they pass from one medium to another is called
    Refraction
  • At the end of the Gram stain, gram-positive bacteria will be seen as red/pink cells.
    false
  • What genus below is an acid-fast bacterium?
    Mycobacterium
  • Select ALL those structures that are found in a gram-positive cell envelope.
    cell membrane
    a thick layer of peptidoglycan
    lipoteichoic acids.
    teichoic acids1 multiple choice option
  • Select ALL those structures that are found in a gram-negative cell envelope.
    The outer membrane
    periplasmic space
    lipopolysaccharide
    cell membrane
    thin layer of peptidoglycan
  • Spirochetes have a twisting and flexing locomotion due to appendages called
    periplasmic flagella
  • The term that refers to the presence of flagella over the cell surface is
    Peritrichous
  • The short, numerous appendages used by some bacterial cells for adhering to surfaces are called
    Pili or fimbriae
  • The transfer of genes during bacterial conjugation involves rigid, tubular appendages called
    sex pili
  • Which structure protects bacteria from being phagocytized by white blood cells?
    capsule
  • what is the purpose of koch postulates?
    To determine etiology of disease
  • Describe in detail each of the steps of Koch's postulates
    Isolation: The microorganism must be isolated from diseased individuals and grown in pure culture. Inoculation: The isolated microorganism is then introduced into a healthy host to see if it causes the same disease. Re-isolation: The microorganism must be re-isolated from the newly infected host and identified as the same as the original pathogen. Repetition: The process must be repeated to confirm consistent results. If the same disease occurs each time and the same microorganism is re-isolated, Koch's postulates are fulfilled.
  • What are some of the limitations to using Koch's postulates
    Koch's postulates can not be used if the sample cannot be grown in a lab or if there is no animal model of infection.
  • The outcome of the Gram stain is based on differences in the cell's
    wall
  • During the Gram stain, ______ cells decolorize when the alcohol is applied
    gram-negative
  • The _____ stain is used to stain and differentiate
    MycobacteriumandNocardiafrom other bacteria.acid-fast
  • Gram-negative bacteria _______.
    are less susceptible to antibiotics that target peptidoglycan than gram-positive organisms
  • Endospores are not
    found in Bacillus and Clostridium
    resistant to heat and chemical destruction
    resistant to destruction by radiation
    living structures
    found in Gram negative bacteria
    Gram negative bacteria
  • Bacterial endospores are
    not produced by Staphylococcus
  • A Gram positive bacterium with regular clusters of spherical cells is
    Staphylococcus
  • A client has a serious upper respiratory infection. A random sample of sputum was taken from the patient coughing up blood. The lab tech said they had isolated a bacterium that
    did not have any peptidoglycan. You hypothesize that the identity of this microbe could possibly beMycoplasma pneumoniae
  • Halobacterium salinarium
    lives in and requires salt. This is an example of an archaeabacterium described as a(n)halophile
  • Lipopolysaccharide is an important cell envelope component of
    gram-negative bacteria
  • A unicellular microorganism was recovered from a hot spring (95°C) in Wyoming. The cells
    lack a nucleus, have a cell wall thatlacks peptidoglycan, andhave 70S ribosomes. Analysis of the plasma membrane reveals that the lipids contain long-chained branched hydrocarbons withether linkages. Please choose the group in which this organism would be classified, based on the description provided.Archaea
  • Select ALL those activities of fungi considered detrimental from a human perspective
    Produce toxins such as aflatoxin
    Cause decomposition of fresh produce
    Cause disease in plants and animals
    Contribute to allergies
  • Select ALL of the groups on this list that are eukaryotes.
    Algae,
    Protozoa
    Fungi
    Helminths
  • Which of the following is not found in eukaryotic cells but is in the cells of bacteria?
    peptidoglycan cell walls
  • An organelle that is a stack of flattened, membranous sacs and functions to receive, modify, and package proteins for cell secretion is the
    Golgi apparatus
  • Amoebiasis (amoebic dysentery) is most commonly contracted through the
    fecal-oral route from contaminated food or water
  • All of the following are helminths
    EXCEPT trypanosomes