Ch 9: Controlling Microbial Growth in the Environment

1. In practical terms in everyday use, which of the following statements provides the definition of sterilization? a. Sterilization eliminates organisms and their spores or endospores. b. Sterilization eliminates harmful microorganisms and viruses. c. Sterilization eliminates prions. d. Sterilization eliminates hyperthermophiles.

a. Sterilization eliminates organisms and their spores or endospores.

6. The endospores of which organism are used as a biologicalindicator of sterilization? a. Bacillus stearothermophilus b. Salmonella enterica c. Mycobacterium tuberculosis d. Staphylococcus aureus

a. bacillus stearothermophilus

13. Biosafety Level 3 includes a. double sets of entry doors. b. pressurized suits. c. showers in entryways. d. all of the above

a. double sets of entry doors

10. Which of the following types of radiation is more widely used as an antimicrobial technique? a. electron beams b. visible light waves c. radio waves d. microwaves

a. electron beams

17. Which of the following disinfectants acts against cell membranes? a. phenol b. peracetic acid c. silver nitrate d. glutaraldehyde

a. phenol

20. Which class of surfactant is most soluble in water? a. quaternary ammonium compounds b. alcohols c. soaps d. peracetic acids

b. alcohols

2. Which of the following substances or processes kills microorganisms on laboratory surfaces? a. antiseptics b. disinfectants c. degermers d. pasteurization

b. disinfectants

16. Which of the following chemicals is active against bacterial endospores? a. copper ions b. ethylene oxide c. ethanol d. triclosan

b. ethylene oxide

14. A sample of E. coli has been subjected to heat for a specified time, and 90% of the cells have been destroyed. Which of the following terms best describes this event? a. thermal death point b. thermal death time c. decimal reduction time d. none of the above

c. decimal reduction time

9. The preservation of beef jerky from microbial growth relies on which method of microbial control? a. filtration b. lyophilization c. desiccation d. radiation

c. desiccation

15. Which of the following substances is least toxic to humans? a. carbolic acid b. glutaraldehyde c. hydrogen peroxide d. formalin

c. hydrogen peroxide

8. Which of the following items functions most like an autoclave? a. a boiling pan b. an incinerator c. a microwave oven d. a pressure cooker

d. a pressure cooker

18. Which of the following disinfectants contains alcohol? a. an iodophor b. a quat c. formalin d. a tincture of bromine

d. a tincture of bromine

4. The microbial death rate is used to measure a. the efficiency of a detergent. b. the efficiency of an antiseptic. c. the efficiency of sanitization techniques. d. all of the above

d. all of the above

5. Which of the following statements is true concerning the selection of an antimicrobial agent? a. An ideal antimicrobial agent is stable during storage. b. An ideal antimicrobial agent is fast acting. c. Ideal microbial agents do not exist. d. all of the above

d. all of the above

12. Which of the following adjectives best describes a surgical procedure that is free of microbial contaminants? a. disinfected b. sanitized c. degermed d. aseptic

d. aseptic

19. Which antimicrobial chemical has been used to sterilize spacecraft? a. phenol b. alcohol c. heavy metal d. ethylene oxide

d. ethylene oxide

11. Which of the following substances would most effectively inhibit anaerobes? a. phenol b. silver c. ethanol d. hydrogen peroxide

d. hydrogen peroxide

7. A company that manufactures an antimicrobial cleaner for kitchen counters claims that its product is effective when used in a 50% water solution. By what means might scientists best verify this statement? a. disk-diffusion test b. phenol coefficient c. filter paper test d. in-use test

d. in-use test

3. Which of the following terms best describes the disinfecting of cafeteria plates? a. pasteurization b. antisepsis c. sterilization d. sanitization

d. sanitization