Question 1

The time required to kill 90% of the microorganisms or spores in a sample at a specified temperature is the

Accepted Answer

A)  thermal death time (TDT) .
B)  thermal death point (TDP) .
C)  decimal reduction time (D value) .
D)  z value.E) None of the above
F) A) and B)

Question 2

Gamma radiation

Accepted Answer

A)  is a type of nonionizing radiation.
B)  has poor penetrating power.
C)  is used to sterilize some food products.
D)  has a longer wavelength than UV radiation.E) A) and B)
F) B) and C)

Question 3

An agent that prevents the growth of bacteria without causing irreversible damage to the bacteria is referred to as __________.

Accepted Answer

bacteriostatic

Question 4

Moist heat sterilizes by

Accepted Answer

A)  causing the formation of thymine dimers.
B)  denaturing proteins.
C)  causing production of singlet oxygen.
D)  all of the choicesE) A) and D)
F) C) and D)

Question 5

Which kind of sterilization procedure takes advantage of the size of microorganisms?

Accepted Answer

A)  autoclaving
B)  open flame
C)  use of chemicals
D)  filtrationE) B) and C)
F) None of the above

Question 6

Which of the following is true about membrane filters?

Accepted Answer

A)  It can be used only to remove organisms from liquids.
B)  It does not truly sterilize because it removes rather than kills microorganisms.
C)  It can be used only to remove organisms from liquids and it does not truly sterilize because it removes rather than kills microorganisms.
D)  It can't be depended on to remove all viruses from liquids.E) B) and D)
F) B) and C)

Question 7

Heavy metals may inactivate proteins by reacting with their sulfhydryl groups.

Accepted Answer

A) True 
 B)False

Question 8

The destruction or removal of all viable organisms is called

Accepted Answer

A)  disinfection.
B)  antisepsis.
C)  sterilization.
D)  sanitization.E) B) and D)
F) A) and B)

Question 9

Which of the following environmental factors generally do(es) not have an impact on the efficiency of an antimicrobial agent?

Accepted Answer

A)  PH.
B)  Presence or absence of a biofilm.
C)  Concentration of organic matter.
D)  Refractive index.E) B) and C)
F) A) and C)

Question 10

If one left a "Pasteurized" flask of broth for a long time at room temperature,it would stay sterile forever,at least in principle.

Accepted Answer

A) True 
 B)False

Question 11

The prevention of infection caused by microorganisms is called

Accepted Answer

A)  disinfection.
B)  antisepsis.
C)  sterilization.
D)  sanitization.E) B) and C)
F) C) and D) B

Question 12

Iodine can be complexed with an organic carrier to form water-soluble,stable complexes called __________,which release iodine slowly and eliminate skin burns and irritation associated with iodine use.

Accepted Answer

A)  iodides
B)  tinctures
C)  iodophors
D)  iodochromesE) B) and D)
F) A) and D) C

Question 13

The reduction of the microbial population to levels that are considered safe by public health standards is called

Accepted Answer

A)  disinfection.
B)  antisepsis.
C)  sterilization.
D)  sanitization.E) B) and C)
F) All of the above

Question 14

The substantial reduction of the total population of microorganisms on inanimate objects and the destruction of potential pathogens is called

Accepted Answer

A)  disinfection.
B)  antisepsis.
C)  sterilization.
D)  sanitization.E) A) and C)
F) C) and D)

Question 15

Ultraviolet radiation is an effective means of sterilizing surfaces.

Accepted Answer

A) True 
 B)False

Question 16

All germicides are capable of killing all pathogenic organisms and endospores.

Accepted Answer

A) True 
 B)False

Question 17

Which will require a longer time to kill?

Accepted Answer

A)  A larger population of microorganisms.
B)  A smaller population of microorganisms.
C)  Killing will be equally as rapid in a large or a small microbial population.
D)  There is no way to predict which will require a longer kill time.E) B) and D)
F) A) and B)

Question 18

Disinfectants are generally regulated by the

Accepted Answer

A)  Food and Drug Administration.
B)  Environmental Protection Agency.
C)  The National Institutes of Health.
D)  Centers for Disease Control and Prevention.E) B) and C)
F) A) and B)

Question 19

Antiseptics are generally regulated by the

Accepted Answer

A)  Food and Drug Administration.
B)  Environmental Protection Agency.
C)  The National Institutes of Health.
D)  Centers for Disease Control and Prevention.E) B) and C)
F) A) and B)

Question 20

The two most important alcohol germicides are __________ and __________.

Accepted Answer

A)  ethanol; methanol
B)  ethanol; isopropanol
C)  methanol; butanol
D)  methanol; isopropanolE) B) and C)
F) A) and B)

Exam 8: Control of Microorganisms in the Environment

The time required to kill 90% of the microorganisms or spores in a sample at a specified temperature is the

Correct AnswerverifiedShow Answer

Gamma radiation

Correct AnswerverifiedShow Answer

An agent that prevents the growth of bacteria without causing irreversible damage to the bacteria is referred to as __________.

Correct Answerverifiedbacteriostatic

Moist heat sterilizes by

Correct AnswerverifiedShow Answer

Which kind of sterilization procedure takes advantage of the size of microorganisms?

Correct AnswerverifiedShow Answer

Which of the following is true about membrane filters?

Correct AnswerverifiedShow Answer

Heavy metals may inactivate proteins by reacting with their sulfhydryl groups.

Correct AnswerverifiedShow Answer

The destruction or removal of all viable organisms is called

Correct AnswerverifiedShow Answer

Which of the following environmental factors generally do(es) not have an impact on the efficiency of an antimicrobial agent?

Correct AnswerverifiedShow Answer

If one left a "Pasteurized" flask of broth for a long time at room temperature,it would stay sterile forever,at least in principle.

Correct AnswerverifiedShow Answer

The prevention of infection caused by microorganisms is called

Correct AnswerverifiedB

Iodine can be complexed with an organic carrier to form water-soluble,stable complexes called __________,which release iodine slowly and eliminate skin burns and irritation associated with iodine use.

Correct AnswerverifiedC

The reduction of the microbial population to levels that are considered safe by public health standards is called

Correct AnswerverifiedShow Answer

The substantial reduction of the total population of microorganisms on inanimate objects and the destruction of potential pathogens is called

Correct AnswerverifiedShow Answer

Ultraviolet radiation is an effective means of sterilizing surfaces.

Correct AnswerverifiedShow Answer

All germicides are capable of killing all pathogenic organisms and endospores.

Correct AnswerverifiedShow Answer

Which will require a longer time to kill?

Correct AnswerverifiedShow Answer

Disinfectants are generally regulated by the

Correct AnswerverifiedShow Answer

Antiseptics are generally regulated by the

Correct AnswerverifiedShow Answer

The two most important alcohol germicides are __________ and __________.

Correct AnswerverifiedShow Answer

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bacteriostatic

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B

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C

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The two most important alcohol germicides are and .

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