Choose one of the following. Improve your microbiology

8. The virulence of an organism may be enhanced by all the following except
a. Its ability to produce exotoxins.
b. Its ability to overcome body defense.
c. Its ability to spread through the tissues.
d. Its ability to grow on artificial laboratory media.

15. A scientist who studies the pattern of disease in a community and attempts to locate its source is called a(n)
a. Pathologist
b. Epidemiologist
c. Microbiologist
d. Infectiologist

16. A person who harbors a pathogen and a source of infection to the next person is best referred to as a(n)
a. Acute source
b. Chronic Source
c. Subclinical source
d. Carrier

18. Endotoxins are generally produced by
a. Fungi
b. Gram positive bacteria
c. Gram negative bacteria
d. The genus bacillus

19. Opsonins may be described as
a. Types of white blood cells
b. Antibodies that enhance the efficiency of phagocytosis
c. Types of Endotoxins produced by bacteria
d. Types of bacterial exotoxins

23. Antigenic determinants are the parts of antigen molecules that
a. Code for antibody molecules
b. Stimulate phagocytosis
c. Stimulate the immune system
d. Clot blood

25. Antibody-mediated immunity is the form of immunity that
a. Requires cell-to-cell contact for antigen neutralization
b. Takes place in the blood
c. Relies on the activity of perforins and granzymes
d. Does not require phagocytosis

26. The uniqueness of an individual is defined in part by the
a. Type of antibodies produced by that individual
b. Antigens to which the individual can respond
c. Ability to produce T cells after passage through the thymus
d. MHC proteins on the surfaces of the individual's cells.

27. The chemical enhancers in cell-mediated immunity are
a. Cytokines, such as the interleukins
b. Chains of amino acids called antibodies
c. Produced by plasma
d. Indentical with cell-surface receptors on B cells

28. A compound that digests the cell wall of a gram positive bacteria is
a. Bile
b. Lysozyme
c. Interferon
d. Stomach acid

32. A neutral barrier to the intestine is provided by the extremely alkaline environment of the stomach contents
a. True
b. False

37. The number of organisms that must be taken into the body for disease to occur is essentially the same for all infectious agents
a. True
b. False

42. Arthropods are important as mechanical vectors of disease even through they never become infected by the parasite
a. True
b. False

45. Organisms in a commensalistic relationship with the human body derive benefit from the body but neither harm nor benefit the body
a. True
b. False

46. Parasites vary greatly in their pathogenicity
a. True
b. False

47. Direct methods for the transmission of disease include consumption of contaminated food or water, an arthropod bite, and contact with fomites.
a. True
b. False

48. An arthropod that is infected and that can transmit parasites is considered a mechanical vector.
a. True
b. False

Please confirm correctness of answers. See attached file for full problem description.