Test #3 Sample Test B


1. An antiseptic is used when one needs to remove microbes from which of the following?
a. toilet surfaces
b. restaurant glassware
c. foods prior to canning
d. food preparation areas
e. skin prior to injection
2. Some antimicrobial treatments kill microbes; some inhibit growth. Which term refers to an agent that inhibits bacterial growth?
a. Fungicidal
b. Bacteriostatic
c. Bacteriocidal
d. Homeostatic
e. Germicidal
3. Which of the following is not a major target for action of antimicrobials?
a. Cell membranes
b. Proteins
c. Nucleic acids
d. Enzymes
e. Flagella
4. Decimal reduction time is the time in minutes in which of the population at a given temperature will be killed
a. 90%
b. 75%
c. 10%
d. 80%
e. 100%
5. Some microbes are very resistant to antimicrobial chemicals. Which of the following would be the most difficult to kill?
a. Pseudomonas aeruginosa
b. Streptococcus pneumoniae
c. Mycobacterium tuberculosis
d. Escherichia coli
e. Clostridium endospores
6. Which type of radiation is least effective in killing microbes?
a. Gamma rays
b. X rays
c. High-energy electron beams
d. Ultraviolet rays
e. Microwaves
7. Alcohol is most effective when used as a solution at which of following concentrations?
a. 70%
b. 95%
c. 60%
d. 100%
e. 25%
8. Which is not a characteristic of the autoclave?
a. The use of moist heat
b. The use of high temperatures
c. The requirement for long (hours) exposure times
d. The use of high pressures
e. The ability to sterilize solutions with endospores
9. You make a dilution by transferring 1 mL of a culture into 99 mL of saline. You then repeat the operation by transferring 1 mL of the diluted culture into another 99 mL bottle of saline. When you inoculate an agar plate with 1.0 mL of the final dilution and obtain 38 colonies. What was the concentration cells in the original culture?
a. 3.8 x 102
b. 3.8 x 103
c. 3.8 x 104
d. 3.8 x 105
e. 3.8 x 106
10. Which of the following is probably NOT bactericidal?
a. lyophilization
b. ionizing radiation
c. incineration
d. autoclaving
e. ethylene oxide gas
11. Choose the best method for the sterilization of an enzyme solution
a. Pasteurization
b. Dry heat
c. Freezing
d. Autoclave
e. Filtration
12. The bactericidal effect of UV light is attributed to damage of which of the following?
a. proteins
b. ribosomes
c. nuclei
d. DNA
e. plasma membranes
13. All of the following methods are used for food preservation except:
a. Deep freezing
b. Dessication
c. Commercial canning
d. Incineration
e. Osmotic pressure
14. A certain bacteria has a generation time of 12 minutes. A culture of 1000 bacteria per mL would be expected to have what concentration of bacteria after an hour?
a. 3.2 x 103 cells/mL
b. 3.2 x 104 cells/mL
c. 3.2 x 105 cells/mL
d. 3.2 x 106 cells/mL
e. 3.2 x 107 cells/mL
15. All of the following are examples of microbial control using heavy metals except which of the following?
a. mouthwash solution containing zinc chloride
b. algae control in swimming pools using copper sulfate
c. antiseptic solution containing mercurochrome
d. benzoyl peroxide used for acne treatment
e. burn treatment using silver-sulfadiazine ointment
16. The following may be listed on the ingredients of your favorite snack food. Which of the following is not antimicrobial?
a. calcium propionate
b. xanthan
c. sodium benzoate
d. sorbic acid
e. potassium sorbate
17. You have a 200 mg/ml antibiotic solution. The first tube contains undiluted antibiotic solution and successive tubes contain serial dilutions (1:2, 1:4, etc.) of the antibiotic;. You then inoculate each tube with Salmonella. Bacteria grow in tubes 4, 5, and 6. You subculture bacteria from tubes 1 through 4 to nutrient broth. Growth occurs in tubes 3 and 4. You can conclude that the MBC (minimum bactericidal concentration) is:
a. 25 mg/mL
b. 12.5 mg/mL
c. 100 mg/mL
d. 50 mg/mL
e. 200 mg/mL
18. The first antibiotic discovered was:
a. Streptomycin
b. Salvarsan
c. Penicillin
d. Sulfa drugs
e. Quinine
19. Which of the following antibiotics inhibits cell wall synthesis?
a. Chloramphenicol
b. Trimethoprim
c. Erythromycin
d. Rifampin
e. Cephalosporin
20. Which of the following antibiotics inhibits protein synthesis?
a. Isoniazid
b. Cephalosporin
c. Streptomycin
d. Vancomycin
e. Rifampin
21. Which of the following is not used for treating bacterial infections?
a. Methicillin
b. Tetracycline
c. Ampicillin
d. Griseofulvin
e. Rifampin
22. Which antimicrobial works by inhibiting the synthesis of mycolic acid?
a. Penicillin
b. Methicillin
c. Isoniazid
d. Vancomycin
e. Chloramphenicol
23. Which of the following antibiotics inhibits folic acid synthesis?
a. Tetracycline
b. Ampicillin
c. Chloramphenicol
d. Sulfanilamide
e. Neomycin
24. Which antifungal drug is commonly used for systemic fungal infections?
a. Tetracycline
b. Ampicillin
c. Chloramphenicol
d. Amphotericin B
e. Neomycin
25. Which is the drug of choice for the treatment of malaria?
a. Flagyl
b. Nifurtimox
c. Quinacrine
d. Iodoquinol
e. Chloroquine
26. Which of the following mechanisms is antifungal?
a. Inhibit ergosterol synthesis
b. Inhibit peptidoglycan synthesis
c. Cause muscle spasms
d. Inhibit 70S ribosomes
e. Interfere with anaerobic metabolism