MICROBIOLOGY 2420

EXAMINATION III

CHOOSE THE MOST CORRECT ANSWER

1. Destruction of pathogenic organisms, especially on inanimate objects best defines

1. sterilization
2. antisepsis
3. disinfection
4. bacteriostasis
5. none of the above

2. Which of the following is not a means of inhibition?

1. low temperature
2. high osmotic pressure
3. removal
4. drying out
5. bacteriostatic drugs

3. Destruction of microorganisms can be accomplished by

1. fire
2. hot ovens
3. chemical agents
4. radiation
5. all of the above

4. When choosing a disinfectant or other control method it is necessary to take into account whether the organism

1. produces spores
2. is present in great numbers
3. possesses a waxy or gelatinous sheath
4. all of the above
5. none of the above

5. A good control agent should

1. not be highly toxic to humans
2. be cheap
3. be easy to apply
4. control the target organism
5. all of the above

6. Which of the following factors effect the interaction of the control agent and organism?

1. temperature
2. pH
3. time
4. contact
5. all of the above

7. You would probably sterilize soiled bandages by

1. heating in an oven
2. autoclave
3. chemicals
4. radiation
5. incineration

8. Boiling water is an excellent disinfectant but cannot be relied upon for sterilization. The reason for this is that

1. it will not kill encapsulated organisms
2. it will not kill endospores
3. it will not kill vegetative cells
4. it will not kill staph organisms
5. all of the above

9. The process by which something may be sterilized by exposing it to boiling water on three successive days is known as

1. autoclaving
2. tyndalization
3. pasteurization
4. Von Hoff’s process
5. None of the above

10. To assure sterilization, compressed steam must reach a temperature of

1. 100 C
2. 111 C
3. 121 C
4. 149 C
5. 500 C

11. Which of the following radiations can be used for sterilization?

1. gamma rays
2. X-rays
3. UV
4. Cathods rays
5. All of the above

12. The great advantage of Beta-Propiolaction (BPL) is that

1. it is cheap
2. it requires a special autoclave
3. it can be used to sterilize entire rooms
4. it requires high humidity
5. all of the above

13. A serum for injection which could not be sterilized by heat or chemicals might be sterilized effectively by

1. aging
2. filtration
3. tyndilization
4. autoclaving
5. treating with ethylene oxide

14. Chlorine gas would most likely be used to disinfect a (an)

1. municipal swimming pool
2. surgical instruments
3. grown
4. operating room
5. none of the above

15. Common laundry bleach is an excellent disinfectant. It consists of a solution of

1. calcium hypochlorite
2. sodium hypochlorite
3. chlorine gas
4. organic chlorine
5. none of the above

16. Silver nitrate has been used extensively

1. as a systemic disinfectant
2. in injectable form
3. as an eyewash for newborns to prevent gonorrhea
4. for puncture wounds
5. none of the above

17. Alcohols are used for

1. thermometer disinfection
2. instrument sterilization
3. vaccine disinfection
4. floor disinfection
5. none of the above

18. Which of the following is not a phenol compound or derivative?

1. cresol
2. hexylesorcinol
3. bis-phenol
4. carbolic acid
5. glucaraldehyde

19. A good example of an oxidazing agent which serves as a disinfectant would be

1. cresol
2. hexylresorcinol
3. formaldehyde
4. hydrogen peroxide
5. nitric acid

20. The major disadvantage of the aldehydes as skin disinfectants would be

1. their high price
2. their lack of effectiveness
3. their high toxicity for human tissues
4. their difficulty of application
5. none of the above

21. Quaternary Ammonium Compounds (QUATS)

1. are good disinfectants
2. are good surface tension reducers
3. have low toxicity for human tissues
4. are effective in high dilutions
5. all of the above

22. Dyes are used

1. as antimicrobial agents in microbial media
2. as antifungal agents
3. as injectable antimicrobial agents
4. a and b
5. a and c

23. A given disinfectant is found to have at a dilution of 1:45 the same killing power as phenol diluted to 1:90. What would be the phenol coefficient of this disinfectant?

1. 2
2. 1
3. .5
4. 5.0
5. none of the above

24. The major weakness with disinfectant comparison testing is

1. use of only one or a few organisms for test purposes
2. conditions which are seldom similar to those of hospitals or clinics
3. bias on the part of the test personnel
4. a and b
5. none of the above

25. Inhibition of growth of microorganisms in food materials may be accomplished by

1. drying
2. adding heavy sugar solutions
3. adding vinegar
4. refrigeration
5. all of the above

26. Sulfanilamide is inhibitory to bacterial growth because

1. it will substitute for PABA
2. it prevents folic acid synthesis
3. it prevents the operation of an essential enzyme
4. all of the above
5. none of the above

27. The sulfonamides were considered "wonder" drugs when first discovered in the thirties. Today they have lost much of their effectiveness. This is due to

1. more effective antibiotics have been discovered in molds
2. the bacterial species which they were effective against have disappeared due to their use
3. widespread use has led to evolutionary selection of mutant forms which are resistant to theses drugs
4. they have been superceded by much cheaper drugs
5. all of the above

28. A chemotheraputic drug which is now, or was in the past, obtained from a living organism is termed

1. sulfonamides
2. antibiotic
3. antimicrobial agent
4. anmtibacterial
5. all of the above

29. Penicillin is usually effective against

1. Gram-positive bacteria
2. Gram-negative bacteria
3. Both positive and negative bacteria
4. Viruses
5. Fungi and Gram-negative bacteria

30. Tetracyclines are effective against

1. Gram-positive bacteria
2. Gram-negative bacteria
3. Both Gram-positive and negative bacteria
4. Viruses and fungi
5. Viruses and Gram-positive bacteria

31. Improper use of antibiotics can lead to

1. toxic effects on humans
2. evolution of antibiotic resistant strains
3. death
4. severe disruption of the normal body flora
5. all of the above

32. The invasion and growth of an organism in the body best defines

1. disease
2. infection
3. pathology
4. virulence
5. all of the above

33. An organism may be highly virulent if

1. it is very aggressive
2. it produces a powerful toxin
3. it is antibiotic resistant
4. it is sulfa drug resistant
5. a and b only

34. The virulence of an organism may be decreased by

1. growing it in unfavorable media
2. passing through a succession of hosts
3. use of antibiotics
4. a and b
5. a and c

35. Antibodies (immunoglobins) are formed by

1. erythrocytes
2. neutrophils
3. monocytes
4. eusinophils
5. none of the above

36. The most abundant leukocyte in the body is the

1. neutrophil
2. basophil
3. monocyte
4. erythrocyte
5. none of the above

37. A macrophage which is fixed to the tissues is referred to as a

1. neutrophil
2. monocyte
3. mast cell
4. histiocyte
5. none of the above

38. The RE system

1. consist of a series of vascular channels which are lined by phagocytic cells
2. is primarily responsible for purification of the blood and lymph
3. is effective against both microorganisms and other debri
4. all of the above
5. none of the above

39. The first line of defense against microbial invasions is

1. the intact skin and mucous membranes
2. phagocytic cells
3. interferon
4. antibody
5. T-cells

40. Human beings can be infected by small pox but dogs cannot. For the dog this is an example of

1. interferon
2. antibody immunity
3. humoral mediate immunity
4. cell mediated immunity
5. none of the above

41. The skin protects against pathogens by

1. forming an intact barrier
2. secreting acids which reduce pH and make life difficult for pathogens
3. secreting lysozyme
4. providing growth areas for normal skin flore which "autocompete" the pathogens
5. all of the above

42. Interferon

1. is produced by body cells when invaded by viruses
2. causes the production of antiviral chemicals by surrounding cells
3. is non-specific viruses
4. protects against viruses
5. all of the above

43. Properdin

1. requires the presence of antibody in order initiate complement fixation
2. is highly specific in its response
3. initiates the fixation of complement in the absence of antibody
4. is the beginning point for the classical pathway of complement fixation
5. all of the above

44. Which of the following is not a component of the inflammatory response?

1. increased blood flow
2. increased capillary filtration (edema, awelling)
3. aggregation of phagocytic cells
4. production of antibody
5. increased temperature in the inflamed area

45. That component of specific immunity which relays exclusively upon cells for the specific response is known as

1. humoral mediated immunity
2. cell mediate immunity
3. interferon mediated immunity
4. complement
5. phagocytosis

46. Before a good immune response can be mounted by either B-cells or T-cells to an antigen

1. the antigen must be immobilized by antibody
2. the antigen must be processed and presented to B-cells by macrophages
3. the antigen must be processed and presented to T-cells by macrophages
4. the antigen must be processed and presented to T-cells by B-cells
5. none of the above

47. Which of the following is not a class of immunoglobulin?

1. IgG
2. IgM
3. IgD
4. IgE
5. IgB

48. Opsonization occurs when

1. antibodies coat cells making them more readily phagocytized
2. antibodies immobilize motile cells
3. antibodies react with complement
4. antibodies neutralize viruses
5. all of the above

49. The fixation of complement is a major mechanism of the immune response when this occurs

1. bacteria are lysed
2. immune adherence of foreign cells to phagocytes takes place
3. an inflammatory response may be initiated
4. all of the above
5. none of the above

50. Antibodies can function by

1. neutralizing viruses
2. precipitating soluble antigen
3. fixing complement
4. agglutinating cells
5. all of the above

51. Cell mediated immunity is principally a function of

1. B-cells
2. Plasma cells
3. T-cells
4. Complement
5. All of the above

52. Which of the following agents is not released during a CMI response?

1. interferon
2. phagocyte immobilizing factors
3. phagocyte attracting factors
4. antibodies

53. The ability of the immune system to recognize and ignore your own body cells and chemicals is termed

1. immune adherence
2. recognition
3. tolerance
4. anaphylaxsis
5. none of the above

54. Natural immunity is obtained by

1. vaccination with the infectious organism
2. a normal encounter with the organism in the environment
3. eating only natural foods
4. avoiding unnatural situations
5. none of the above

55. A vaccine may be prepared using

1. live, virulent organisms
2. active toxins
3. dead organisms
4. all of the above
5. none of the above

56. Many common infections seem to run about 2 weeks before disappearing. The reason for this is

1. the secondary response was slow in occurring
2. the secondary response was too weak
3. it takes the body about that long to mount a full immune attack when meeting an organism for the first time
4. it takes the body about that long to mount a full immune response when meeting an organism for the 2^nd or 3^rd time
5. none of the above

57. A case of natural passive immunity occurs when

1. vaccinations are given
2. antibo\dy is injected against a particular antigen
3. antibodies are given prior to exposure to an infectious disease
4. mothers given antibody to fetus
5. all of the above

58. Mast cells play a major role in immediate hypersensitivity because they

1. bind antibody E
2. immobilize phagocytes
3. attract phagocytes
4. release chemical agents which are responsible for the body manifestation of the response
5. all of the above

59. Delayed hypersensitivity is mediated by

1. HMI
2. CMI
3. Both HMI & CMI
4. Mast cells
5. None of the above

60. The tuberculin test

1. requires that antigen of tuberculosis causing organisms be rubbed into the skin
2. will show a miner inflammatory response if positive
3. is regulated by CMI
4. demonstrates that population of lymphocytes exist which "know" the tuberculosis organism
5. all of the above