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General Microbiology II

Sample Questions for Exam 3 (April 6)

MULTIPLE CHOICE: Choose the letter corresponding to the ONE answer for each question.

  1. Which statement about virulence factors is true?
    a. Invasiveness factors promote the ability of microbes to enter a host and set up infections that may lead to disease.
    b. Opportunistic pathogens possess no virulence factors, but depend solely on host defects for their virulence.
    c. Microbial toxins promote the ability of the host to fend off infectious agents by blocking inflammation.

  2. Which statement about innate host defense mechanisms is true?
    a. Host resistance mechanisms are said to be highly specific in their activities because they do not affect a broad range of microbes.
    3. b. Chemical host defense factors include enzymes, complement, salts, fatty acids, and mucus (which is also a physical host defense factor).
    c. Peristalsis functions only as an internal host defense mechanism by dissolving infectious agents while they are in our intestines.

MATCHING MULTIPLE CHOICE: Choose the BEST answer. An answer may be used more than once within the set of questions indicated.

Answers to questions 3-4:

a. Cytotoxic T lymphocytes (CTLs)
b. Activated macrophages
c. Enhancement of phagocytosis
d. Complement-mediated lysis
e. Neutralization by antibody
  1. __________ would be the least important in eliminating extracellular infectious agents (those that grow outside of host cells).

  2. __________ are the primary mediators of immunity to facultative intracellular parasites (those that can live either inside or outside of host cells).

TRUE FALSE: If a statement is TRUE, enter A on the answer sheet; if it is FALSE, enter B.

  1. To prevent a disease whose signs and symptoms result from a toxin, vaccine antigens must be engulfed and presented by phagocytes, which then stimulate T helper cells to multiply and stimulate B cells, which mature to form a large number of plasma cells that produce and secrete antibody molecules.
     
  2. Because common-source epidemics develop by transfer of microbes from person-to-person as they spread though a susceptible population, these epidemics are characterized by rapid onset, a "sharp" peak and a rapid decline in incidence.

To help you prepare for exam 3, I have scheduled a help session in room 116 PSN from 4:00 to 5:00 pm on April 3.