Bacterial Classification and Morphology Quiz
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Questions and Answers

What is the primary method by which most bacteria multiply?

  • Budding
  • Binary fission (correct)
  • Fragmentation
  • Mitosis
  • Which of the following bacterial shapes is characterized as being twisted?

  • Coccus
  • Bacillus
  • Vibrio
  • Spiral (correct)
  • What term describes cocci that remain in pairs after cell division?

  • Tetrads
  • Staphylococci
  • Streptococci
  • Diplococci (correct)
  • What characteristic distinguishes bacilli from cocci regarding their grouping after division?

    <p>Bacilli only divide across their short axis</p> Signup and view all the answers

    Which of the following terms refers to a group of cocci that remain together in grape-like clusters?

    <p>Staphylococci</p> Signup and view all the answers

    Which of the following best describes the classification of bacteria based on their nutritional requirements?

    <p>Energy source</p> Signup and view all the answers

    What term is used to describe bacteria that can assume several different shapes?

    <p>Pleomorphic</p> Signup and view all the answers

    Which size range is typical for most bacteria?

    <p>0.2 um to 8 um</p> Signup and view all the answers

    What clinical findings are associated with group B streptococcal infection during the first month of life?

    <p>Sepsis</p> Signup and view all the answers

    How does intravenous ampicillin help mothers who carry group B streptococcus?

    <p>Prevents the colonization of their infants</p> Signup and view all the answers

    Which of the following describe Streptococcus pneumoniae?

    <p>Gram positive diplococci</p> Signup and view all the answers

    What is the most common urinary tract infection-causing organism?

    <p>Escherichia coli</p> Signup and view all the answers

    What is a common symptom of Shigella infection?

    <p>Abdominal pain</p> Signup and view all the answers

    Which of the following correctly describes Vibrios?

    <p>Aerobic and motile</p> Signup and view all the answers

    What is the primary pathogenic characteristic of Vibrio cholerae?

    <p>Pathogenic only for humans</p> Signup and view all the answers

    What symptoms might indicate E. coli's association with diarrheal diseases?

    <p>Abdominal pain and watery diarrhea</p> Signup and view all the answers

    What is the primary mode of transmission for Treponema pallidum?

    <p>Sexual contact</p> Signup and view all the answers

    What is a characteristic symptom of cholera infection?

    <p>Rice water stools</p> Signup and view all the answers

    What happens to the mortality rate of cholera without treatment?

    <p>It can rise to between 25%-50%</p> Signup and view all the answers

    Which of the following is a feature of Treponema pallidum?

    <p>Slender spirals that are actively motile</p> Signup and view all the answers

    What is the incubation period for syphilis caused by Treponema pallidum?

    <p>2-10 weeks</p> Signup and view all the answers

    Which type of lesion develops at the site of Treponema pallidum infection?

    <p>Hard chancre</p> Signup and view all the answers

    What characterizes the primary lesion in Treponema pallidum infection?

    <p>It heals spontaneously</p> Signup and view all the answers

    Which condition increases susceptibility to Vibrio cholerae infection?

    <p>Decreased stomach acidity</p> Signup and view all the answers

    What is the primary function of flagella in bacteria?

    <p>Locomotion</p> Signup and view all the answers

    Leptospirae typically grow best under which conditions?

    <p>Aerobic at 28-30 degrees Celsius</p> Signup and view all the answers

    Which of the following is NOT a type of cell surface appendage in bacteria?

    <p>Cilia</p> Signup and view all the answers

    What is one symptom of leptospirosis during its biphasic illness?

    <p>Jaundice</p> Signup and view all the answers

    How do leptospirae typically enter the human body?

    <p>Through breaks in the skin and mucous membranes</p> Signup and view all the answers

    What laboratory test can be performed to diagnose leptospirosis?

    <p>Dark-field examination</p> Signup and view all the answers

    What is the structure of leptospirae as seen under a microscope?

    <p>Thin, flexible spirochetes</p> Signup and view all the answers

    What is the incubation period for leptospirosis?

    <p>1-2 weeks</p> Signup and view all the answers

    What is the primary function of pili in bacteria?

    <p>Helping bacteria adhere to host cells</p> Signup and view all the answers

    Inclusion bodies in bacteria typically consist of what substances?

    <p>Viruses and proteins</p> Signup and view all the answers

    What distinguishes differential staining from simple staining?

    <p>Application of multiple stains</p> Signup and view all the answers

    Which of the following is a characteristic feature of Gram-negative bacteria?

    <p>Higher lipid content in cell wall</p> Signup and view all the answers

    What is typically stored in the form of polyhydroxyalkanoates or glycogen in bacteria?

    <p>Excess carbon</p> Signup and view all the answers

    Which of the following stains is commonly used in simple staining procedures?

    <p>Crystal violet</p> Signup and view all the answers

    What information can be gathered from a WBC differential test?

    <p>Abnormalities in white blood cell proportions</p> Signup and view all the answers

    What is commonly associated with sulfur granules in bacteria?

    <p>Utilization of hydrogen sulfide as an electron source</p> Signup and view all the answers

    Study Notes

    Bacteria

    • Bacteria are single-celled organisms that multiply by binary fission
    • Bacteria can be differentiated by their morphology, chemical composition, nutritional requirements, biochemical activities, and source of energy

    Size, shape, and arrangement of bacteria cells

    • Most bacteria are 0.2 um in diameter and 2-8 um in length
    • The three basic bacterial shapes are coccus (spherical), bacillus (rod-shaped), and spiral (twisted)
    • Pleomorphic bacteria can assume several shapes
    • Cocci that remain in pairs after dividing are called diplococci
    • Cocci that divide in multiple planes and form grape-like clusters or sheets are called staphylococci
    • Cocci that remain in chains after dividing are called streptococci
    • Cocci that divide in two planes and remain in groups of four are called tetrads
    • Most bacilli appear as single rods
    • Diplobacilli appear in pairs
    • Streptobacilli appear in chains after division
    • Some bacilli are so short and fat that they look like cocci and are referred to as coccobacilli
    • Spiral bacteria have one or more twists
    • Vibrios look like curved rods
    • Spirilla have a helical shape and fairly rigid bodies

    Appendages of bacteria

    • Appendages are proteinaceous tubular or fibrous structures found on the surface of bacterial cells
    • Appendages extend from the surface of the bacterial cell wall
    • Appendages have many functions including locomotion, attachment, adhesion, and assisting in genetic exchange

    Types of appendages

    • Flagella are the most important for locomotion and can also act as a sensory organ
    • Fimbriae are bristle-like short fibres that enable bacterial cells to stick to the surface of host cells and help form pellicles or biofilms
    • Pili are long hair-like tubular microfibres found on the surface of some Gram-negative bacteria

    Inclusions of bacteria

    • Inclusion bodies are nuclear or cytoplasmic aggregates of stainable substances, usually proteins
    • Inclusion bodies typically represent sites of viral multiplication in a bacterium or eukaryotic cell and usually consist of viral capsid proteins
    • Researchers have recovered folded protein from inclusion bodies
    • Many bacteria store excess carbon in the form of polyhydroxyalkanoates or glycogen

    Distinguishing features of stains

    • Simple stains involve only one stain
    • Basic stains, such as methylene blue, Gram safranin, or Gram crystal violet are useful for staining most bacteria

    Differential stains

    • Differential stains use more than one chemical stain
    • Differential stains help differentiate between different microorganisms or structures/cellular components of a single organism
    • Differential staining is used to detect abnormalities in the proportion of different white blood cells in the blood and is useful because many diseases alter the proportion of certain white blood cells
    • Gram staining is a differential stain that uses two dyes: Crystal violet and Fuschsin or Safranin to differentiate between Gram-positive bacteria and Gram-negative bacteria.

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    Description

    Test your knowledge on bacteria, their shapes, and reproduction methods. This quiz covers various types of bacteria including cocci, bacilli, and their arrangements. Dive into the fascinating world of microbiology and enhance your understanding of these essential organisms.

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