Ch 7

In the figure, the decimal reduction time (D value) for the culture is approximately 40 min 60 min 30 min 0 min 10 min

10 min

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper? ultraviolet radiation gamma radiation autoclave microwaves sunlight

gamma radiation

The antimicrobial activity of chlorine is due to which of the following? the formation of a hypochlorite ion the formation of hypochlorous acid disruption of the plasma membrane the formation of ozone the formation of hydrochloric acid

the formation of hypochlorous acid

Oxidizing agents include all of the following EXCEPT iodine chlorine hydrogen peroxide ozone glutarlydehyde

glutarlydehyde

All of the following are methods of food preservation EXCEPT high pressure ionizing radiation osmotic pressure microwaves desiccation

microwaves

Bone and tendons for transplant are decontaminated by glutaraldehyde .plasma sterilization. supercritical fluids. peroxygens. ethylene oxide.

supercritical fluids

In the figure, what is the thermal death time? The answer cannot be determined 60 min 100 C 150 C 120 min

60 min

Which concentration of ethanol is the most effective bactericide? 100% 70% 50% 40% 30%

70%

Which of the following regarding antimicrobial control agents is false? Some agents affect microbial cell membranes by dissolving lipids. Some agents kill by denaturing microbial cell proteins. Contaminating organic debris such as blood or sputum will decrease effectiveness. A true antimicrobial control agent is equally effective against both bacteria and viruses. Some agents are utilized as both an antiseptic and a disinfectant.

A true antimicrobial control agent is equally effective against both bacteria and viruses

In the table, which disinfectant was bactericidal? Aotus Gorb Komodo Tula The answer cannot be determined

Aotus

In the table, which compound was the most effective against Staphylococcus?

C

Which of the following is a limitation of the autoclave? It cannot be used with glassware It requires an excessively long time to achieve sterilization It cannot inactivate viruses It cannot be used with heat-labile materials It cannot kill endospores

It cannot be used with heat labile materials

Which of the following regarding antimicrobial control agents if false? Silver is used for treating antibiotic-resistant bacteria. Some agents kill by denaturing microbial cell proteins. Contaminating organic debris such as blood or sputum decrease effectiveness. Some agents inactivate viruses by attacking cell membrane lipids. Some agents affect microbial cell membranes by dissolving lipids.

Some agents inactivate viruses by attacking cell membrane lipids

Which of the following treatments is the most effective for controlling microbial growth? 63°C for 30 minutes 72°C for 15 seconds 140°C for 4 seconds They are equivalent treatments. None of the answers is correct.

They are equivalent treatments

In the table, which compound was bactericidal?

The answer cannot be determined

In the table, which compound was the most effective against E. coli?

The answer cannot be determined

In the table, which disinfectant was most effective against Salmonella? Doom Steri K.O. Mortum The answer cannot be determined

The answer cannot be determined

In the table, which disinfectant is the most effective at stopping bacterial growth? Tula Gorb Aotus Komodo The answer cannot be determined

Tula

All of the following substances are effective against non-enveloped viruses EXCEPT chlorine ozone ethylene oxide alcohol All are equally effective against non-enveloped viruses

alcohol

Which of the following pairs is mismatched? CuSO4 algicide organic acids food preservation alcohols open wounds H2O2 open wounds Ag wound dressings

alcohols open wounds

Which graph in the figure best depicts the effect of placing the culture in an autoclave for 15 minutes at time x?

b

Which of the following pairs of terms is mismatched? sterilant destroys all living microorganisms germicide-kills microbes fungicide kills yeast and molds virucide-inactivates viruses bacteriostatic kills vegetative bacteral cells

bacteriostatic kills vegetative bacterial cells

All of the following substances are used to preserve foods EXCEPT nisin calcium propionate potassium sorbat biguanides sodium nitrite

biguanides

All of the following are effective for destroying prions EXCEPT NaOH + autoclaving at 134°C. proteases. boiling. incineration .Each of the answers will destroy prions.

boiling

Which graph in the figure best depicts the effect of placing the culture at 7°C at time x?

d

Application of heat to living cells can result in all of the following EXCEPT alteration of membrane permeability damage to nucleic acids breaking of hydrogen bonds denaturation of enzymes decreased thermal death time

decreased thermal death time

The preservation of beef jerky from microbial growth relies on which method of microbial control? supercritical CO2 filtration lyophilization ionizing radiation desiccation

desiccation

An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n) aseptic antiseptic disinfectant fungicide virucide

disinfectant

Which of the following chemical agents is used for sterilization? ethylene oxide soap phenolics chlorine alcohol

ethylene oxide

Which of the following results in lethal damage to nucleic acids? heat radiation certain chemicals heat and radiation heat, radiation, and some chemicals

heat, radiation, and some chemicals

An iodophor is a(n) quaternary ammonium compound agent that reduces Oxygen form of formaldehyde phenol iodine mixed with a surfactant

iodine mixed with a surfactant

Which of the following is the best method to sterilize heat-labile solutions? pasteurization dry heat freezing membrane filtration autoclave

membrane filtration

Which one of the following is most resistant to chemical biocides? mycobacteria gram-positve bacteria protozoan cysts viruses with lipid envelopes gram-negative bacteria

mycobacteria

Which of the following does NOT achieve sterilization? supercritical fluids ethylene oxide dry heat autoclave pasteurization

pasteurization

If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar? pressure cooker at 121°C for 15 minutes boiling for 1 hour oven at 121°C for 1 hour bleach hydrogen peroxide

pressure cooker at 121 C for 15 min

In the table, which preservative is most effective? potassium sorbate sodium benzoate potassium sorbate + sodium benzoate no preservative

sodium benzoate