Microbiology - Block 2

36 Questions | Total Attempts: 158

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Microbiology Quizzes & Trivia

Questions and Answers
  • 1. 
    Which of these is not a end-result (product) of oxygen-dependent myeloperoxidase-independent reactions?
    • A. 

      Singlet Oxygen

    • B. 

      Hydrogen Peroxide

    • C. 

      Chlorous Acid

    • D. 

      Hydroxyl Radical

    • E. 

      Superoxide Anion

  • 2. 
    Which of these is an end-result (product) of oxygen-dependent myeloperoxidase-dependent reactions?
    • A. 

      Hydroxyl Radical

    • B. 

      Hydrochloric Acid

    • C. 

      Hydrogen Peroxide

    • D. 

      Hypochlorous Acid

    • E. 

      Superoxide Dismutase

  • 3. 
    What is one product that oyxgen-dependent myeloperoxidase-dependent and myeloperoxidase-independent reactions share?
    • A. 

      Superoxide Anion

    • B. 

      Water

    • C. 

      Hydrogen Peroxide

    • D. 

      Hypochlorous Acid

    • E. 

      Ozone

  • 4. 
    Detoxification can break down superoxide anions produced by respiratory burst mechanisms. Which of these is a product of this reaction?
    • A. 

      Ozone

    • B. 

      Hydrogen Peroxide

    • C. 

      Hypochlorous Acid

    • D. 

      Singlet Oxygen

    • E. 

      NADPH

  • 5. 
    Myeloperoxidase pathways can occur without oxygen. 
    • A. 

      True

    • B. 

      False

  • 6. 
    Which of these are intracellular killing pathways?
    • A. 

      Nitric Oxide Dependent Killing

    • B. 

      Oxygen Dependent Myeloperoxidase-Independent Killing

    • C. 

      Oxygen Independent Killing

    • D. 

      Oxygen Dependent Myeloperoxidase-Dependent Killing

    • E. 

      All of the above

    • F. 

      B, C, and D

  • 7. 
    The principal difference between cytotoxic (type II) and immune complex (type III) hypersensitivity is
    • A. 

      The class (isotype) of antibody.

    • B. 

      The site where antigen-antibody complexes are formed.

    • C. 

      The participation of complement.

    • D. 

      The participation of T cells.

  • 8. 
    After binding to its specific antigen, a B lymphocyte may switch its
    • A. 

      Immunoglobulin light-chain isotype.

    • B. 

      Immunoglobulin heavy-chain class.

    • C. 

      Variable region of the immunoglobulin heavy chain.

    • D. 

      Constant region of the immunoglobulin light chain.

  • 9. 
    C3a and C5a can cause
    • A. 

      Bacterial lysis.

    • B. 

      Vascular permeability.

    • C. 

      Phagocytosis of IgE-coated bacteria.

    • D. 

      Aggregation of C4 and C2.

  • 10. 
    Complement fixation refers to
    • A. 

      the ingestion of C3b-coated bacteria by macrophages

    • B. 

      The destruction of complement in serum by heating at 56°C for 30 minutes.

    • C. 

      The binding of complement components by antigen-antibody complexes.

    • D. 

      the interaction of C3b with mast cells

  • 11. 
    Natural killer cells are
    • A. 

      B cells that can kill without complement

    • B. 

      Cytotoxic T cells

    • C. 

      Increased by immunization

    • D. 

      Able to kill virus-infected cells without prior sensitization.

  • 12. 
    A positive tuberculin skin test (a delayed hypersensitivity reaction) indicates that
    • A. 

      A humoral immune response has occurred.

    • B. 

      A cell-mediated immune response has occurred

    • C. 

      Both the T and B cell systems are functional

    • D. 

      Only the B cell system is functional

  • 13. 
    Antigen-presenting cells that activate helper T cells must express which one of the following on their surfaces?
    • A. 

      IgE

    • B. 

      Gamma Interferon

    • C. 

      Class I MHC antigens

    • D. 

      Class II MHC antigens

  • 14. 
    Complement lyses cells by
    • A. 

      Enzymatic digestion of the cell membrane

    • B. 

      Activation of adenylate cyclase

    • C. 

      Insertion of complement proteins into the cell membrane

    • D. 

      Inhibition of elongation factor 2

  • 15. 
    Which one of the following properties of antibodies is NOT dependent on the structure of the heavy-chain constant region?
    • A. 

      Ability to cross the placenta

    • B. 

      Isotype (class)

    • C. 

      Ability to fix complement

    • D. 

      Affinity for antigen

  • 16. 
    Your patient became ill 10 days ago with a viral disease. Laboratory examination reveals that the patient's antibodies against this virus have a high ratio of IgM to IgG. What is your conclusion?
    • A. 

      It is unlikely that the patient has encountered this organism previously

    • B. 

      The patient is predisposed to IgE-mediated hypersensitivity reactions

    • C. 

      The information given is irrelevant to previous antigen exposure

    • D. 

      It is likely that the patient has an autoimmune disease

  • 17. 
    The role of the macrophage during an antibody response is to
    • A. 

      Make antibody

    • B. 

      Lyse virus infected target cells

    • C. 

      Activate Cytotoxic T cells

    • D. 

      Process antigen and present it

  • 18. 
    The main advantage of passive immunization over active immunization is that
    • A. 

      It can be administered orally

    • B. 

      It provides antibody more rapidly

    • C. 

      Antibody persists for a longer period

    • D. 

      It contains primarily IgM

  • 19. 
    Each of the following statements concerning class I MHC proteins is correct EXCEPT:
    • A. 

      They are cell surface proteins on virtually all cells

    • B. 

      They are recognition elements for cytotoxic T cells

    • C. 

      They are codominantly expressed

    • D. 

      They can utilize recombination to generate diversity

  • 20. 
    Each of the following statements concerning class II MHC proteins is correct EXCEPT:
    • A. 

      They are made of a long alpha chain and short beta chain

    • B. 

      They have a high degree of polymorphism

    • C. 

      They are involved in antigen presentation by macrophages

    • D. 

      They have a binding site for CD4 proteins

  • 21. 
    Oxygen-independent killing utilizes all of the following EXCEPT..
    • A. 

      Respiratory Burst mechanism

    • B. 

      Lysozyme

    • C. 

      Lactoferrin

    • D. 

      Proteases

  • 22. 
    Name the intercellular chemical signal that is released by cells and has a local effect on the same cell type as that from which the chemical signal is released.
    • A. 

      Paracrine Chemical Signal

    • B. 

      Hormone

    • C. 

      Autocrine Chemical Signal

    • D. 

      Hormone

    • E. 

      Neurotransmitter

  • 23. 
    __________ are released by cells and affect other cell types locally without being transported in blood.
    • A. 

      Autocrine Chemical Signals

    • B. 

      Paracrine Chemical Signals

    • C. 

      Hormones

    • D. 

      Neurotransmitters

  • 24. 
    Which of these is not related to immunogenicity?
    • A. 

      Age of patient

    • B. 

      Protein Structure

    • C. 

      Size of molecule

    • D. 

      Route of administration

    • E. 

      All of the above are related to immunogenicity

  • 25. 
    Which of these is an example of a T-dependent antigen?
    • A. 

      Protein

    • B. 

      Water

    • C. 

      Polysaccharide

    • D. 

      Cholesterol