Question 1

In order to speed up the sterilization process,which of the following would be useful?

Accepted Answer

A)  Drying the material
B)  Washing/mechanical removal of bacteria/organic matter
C)  Addition of organics
D)  Nothing
E)  Washing/mechanical removal of bacteria/organic matter AND addition of organics

Question 2

Chlorhexidine

Accepted Answer

A)  is a member of the biguanides.
B)  is extensively used in antiseptics.
C)  is ineffective against vegetative bacteria.
D)  is limited in use due to its high toxicity.
E)  is a member of the biguanides AND is extensively used in antiseptics. E

Question 3

Pasteurization

Accepted Answer

A)  is the use of heat to sterilize food products.
B)  is the use of heat to reduce numbers of pathogenic/spoilage bacteria in a food item to a safe level.
C)  is a process that uses intense cold to kill microorganisms on foods.
D)  is a process that uses short bursts of radiation to kill microorganisms on foods.

Question 4

To reduce or eliminate disease-/spoilage-causing organisms,food is often subjected to

Accepted Answer

A)  heat.
B)  chemical additives.
C)  radiation.
D)  cold.
E)  All of the choices are correct.

Question 5

The more bacteria one starts with,the longer it will take to kill them all.

Accepted Answer

A) True 
 B)False  True

Question 6

100% ethanol is twice as effective as 60% ethanol at controlling bacteria.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following organisms are resistant to destruction by typical disinfection methods?

Accepted Answer

A)  Endospores of Bacillus and Clostridium
B)  Pseudomonas
C)  Non-enveloped viruses
D)  Mycobacterium spp.
E)  All of the choices are correct. E

Question 8

Which of the following is not a sterilization method?

Accepted Answer

A)  Hot air oven
B)  Autoclave
C)  Pasteurization
D)  Filtration

Question 9

Upon heat treatment,bacteria die at a constant proportion.

Accepted Answer

A) True 
 B)False

Question 10

Compounds of tin,mercury,arsenic,and copper are no longer used to prevent microbial growth in cooling water primarily because

Accepted Answer

A)  antibiotics are cheaper.
B)  other chemicals were shown to be much more effective.
C)  microbes developed resistance to these metals.
D)  their use contributes to serious pollution of natural waters.
E)  All of the choices are correct.

Question 11

Dry heat takes a much shorter time to sterilize material than wet heat.

Accepted Answer

A) True 
 B)False

Question 12

A common application of dry heat in the microbiology laboratory is to

Accepted Answer

A)  prepare specimens for study.
B)  sterilize media.
C)  sterilize plastics.
D)  sterilize the inoculating loop.

Question 13

One of the first chemicals used by Lister to prevent surgical infections was

Accepted Answer

A)  alcohol.
B)  iodine.
C)  carbolic acid.
D)  mercury.

Question 14

Commercial canning processes

Accepted Answer

A)  are geared to destroy Clostridium botulinum spores.
B)  kill all endospores.
C)  are especially needed on low acid foods.
D)  are 12D processes (designed to kill 1012 endospores) .
E)  are geared to destroy Clostridium botulinum spores,are especially needed on low acid foods,AND are 12D (designed to kill 1012 endospores) processes.

Question 15

Microwaves do not kill organisms directly but kill by

Accepted Answer

A)  the heat they generate in a product.
B)  generating free radicals.
C)  generating toxins.
D)  creating thymine dimers.

Question 16

Pasteurization results in the sterilization of food products.

Accepted Answer

A) True 
 B)False

Question 17

The autoclave treatment may be monitored by

Accepted Answer

A)  heat-sensitive tape.
B)  heat-resistant endospores of Geobacillus stearothermophilus.
C)  pressure indicators alone.
D)  waiting for contaminants to appear on freshly poured media.
E)  heat-sensitive tape AND heat-resistant endospores ofGeobacillus stearothermophilus.

Question 18

Generally,membrane filters are not used to remove

Accepted Answer

A)  bacteria from liquids.
B)  microorganisms from gases.
C)  spoilage agents from alcoholic beverages.
D)  enzymes.

Question 19

Silver sulfadiazine,a combination of silver and a sulfa drug,is used to

Accepted Answer

A)  disinfect water for drinking.
B)  prevent infection of surgical wounds.
C)  prevent infection of second- and third-degree burns.
D)  counteract lead poisoning.
E)  treat bites from werewolves.

Question 20

Upon treatment with heat or chemicals,bacteria will

Accepted Answer

A)  all die immediately.
B)  die at a constant proportion.
C)  die at an exponential rate.
D)  die at a geometric rate.

Exam 5: Control of Microbial Growth

In order to speed up the sterilization process,which of the following would be useful?

Correct AnswerverifiedShow Answer

Chlorhexidine

Correct AnswerverifiedE

Pasteurization

Correct AnswerverifiedShow Answer

To reduce or eliminate disease-/spoilage-causing organisms,food is often subjected to

Correct AnswerverifiedShow Answer

The more bacteria one starts with,the longer it will take to kill them all.

Correct AnswerverifiedTrue

100% ethanol is twice as effective as 60% ethanol at controlling bacteria.

Correct AnswerverifiedShow Answer

Which of the following organisms are resistant to destruction by typical disinfection methods?

Correct AnswerverifiedE

Which of the following is not a sterilization method?

Correct AnswerverifiedShow Answer

Upon heat treatment,bacteria die at a constant proportion.

Correct AnswerverifiedShow Answer

Compounds of tin,mercury,arsenic,and copper are no longer used to prevent microbial growth in cooling water primarily because

Correct AnswerverifiedShow Answer

Dry heat takes a much shorter time to sterilize material than wet heat.

Correct AnswerverifiedShow Answer

A common application of dry heat in the microbiology laboratory is to

Correct AnswerverifiedShow Answer

One of the first chemicals used by Lister to prevent surgical infections was

Correct AnswerverifiedShow Answer

Commercial canning processes

Correct AnswerverifiedShow Answer

Microwaves do not kill organisms directly but kill by

Correct AnswerverifiedShow Answer

Pasteurization results in the sterilization of food products.

Correct AnswerverifiedShow Answer

The autoclave treatment may be monitored by

Correct AnswerverifiedShow Answer

Generally,membrane filters are not used to remove

Correct AnswerverifiedShow Answer

Silver sulfadiazine,a combination of silver and a sulfa drug,is used to

Correct AnswerverifiedShow Answer

Upon treatment with heat or chemicals,bacteria will

Correct AnswerverifiedShow Answer

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