Deck 9: Physical and Chemical Control of Microbes

Question 1

Which of the following types of control agents would be used to achieve sterility?

A)Virucide
B)Bactericide
C)Germicide
D)Sporicide
E)Fungicide

Answer 1

D

Question 2

The removal of all life forms from inanimate objects is termed ________.

A)antisepsis
B)disinfection
C)sterilization
D)decontamination
E)degerming

Answer 2

C

Question 3

Each of the following is the target of antimicrobial agents except ________.

A)cell walls
B)cell membranes
C)ribosomes
D)cellular proteins
E)cytoplasm

Answer 3

E

Question 4

A cleansing method that mechanically removes microbes and other debris to reduce contamination is ________.

A)disinfection
B)sterilization.
C)antisepsis
D)sanitization
E)degermation

Question 5

Which of the following microbial forms have the highest resistance to physical and chemical controls?

A)Naked viruses
B)Protozoan cysts
C)Fungal spores
D)Bacterial endospores
E)Yeast

Question 6

The process that destroys or removes all microorganisms and microbial forms including bacterial endospores on inanimate objects is ________.

A)disinfection
B)sterilization
C)antisepsis
D)sanitization
E)degermation

Question 7

Surfactants work by ________.

A)coating the organism,preventing interaction with its environment
B)blocking transport into the organism
C)blocking transport out from the organism
D)disrupting membrane integrity
E)All of the choices are correct

Question 8

The easiest microbial forms to kill or inhibit are ________.

A)prions
B)vegetative bacteria and fungi
C)endospores
D)protozoan cysts
E)mycobacteria and staphylococci

Question 9

Microbial death occurs when there is ________.

A)no movement
B)permanent loss of reproduction
C)a change in appearance
D)a decrease in size
E)All of these occur

Question 10

The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is ________.

A)disinfection
B)sterilization
C)antisepsis
D)sanitization
E)degermation

Question 11

Some microbial control agents are able to ________ cell proteins by breaking bonds that maintain the native state (three-dimensional configuration)of the proteins.

A)denature
B)bind
C)dissolve
D)activate
E)All of the choices are correct.

Question 12

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is ________.

A)disinfection
B)sterilization
C)antisepsis
D)sanitization
E)ionization

Question 13

The betadine swab before blood donation is an example of ________.

A)antisepsis
B)disinfection
C)sterilization
D)decontamination
E)sanitation

Question 14

Which of the following factors will influence the action of antimicrobial agents?

A)The number of microorganisms
B)The kind of microorganisms
C)Temperature and pH
D)Mode and dosage of the agent
E)All of these will influence the action.

Question 15

The method of removing vegetative microbial life forms from inanimate objects is termed ________.

A)antisepsis
B)disinfection
C)sterilization
D)decontamination
E)degerming

Question 16

The use of a physical or chemical process to destroy vegetative pathogens is ________.

A)disinfection
B)sterilization
C)antisepsis
D)sanitization
E)degermation

Question 17

Which is correct regarding the rate of microbial death?

A)Cells die at increasingly greater rates.
B)Only older cells die in a culture.
C)Cells in a culture die at a constant rate.
D)Upon contact with the control agent,all cells die at one time.
E)Cells become metabolically inactive,but are never killed.

Question 18

The alcohol wipe before an injection is an example of ________.

A)antisepsis
B)disinfection
C)sterilization
D)decontamination
E)virilization

Question 19

The method of removing vegetative life forms from living surfaces is termed ________.

A)antisepsis
B)disinfection
C)sterilization
D)decontamination
E)degerming

Question 20

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is ________.

A)disinfection
B)sterilization
C)antisepsis
D)sanitization
E)ionization

Question 21

Disinfection of beverages such as apple juice,milk,wine is optimally achieved by ________.

A)pasteurization
B)chlorination
C)moist heat autoclave
D)hydrogen peroxide
E)boiling water

Question 22

Removal of moisture by dehydration is called ________.

A)desiccation
B)flash freeze
C)lyophilization
D)pasteurization
E)sterilization

Question 23

Physical agents for controlling microbial growth include all the following except ________.

A)ultraviolet radiation
B)boiling water
C)HEPA filters
D)pasteurization
E)hydrogen peroxide

Question 24

Agents that can denature microbial proteins include all of the following except ________.

A)moist heat
B)alcohol
C)acids
D)metallic ions
E)X rays

Question 25

Pasteurization ________.

A)kills all vegetative forms
B)reduces the number of vegetative forms
C)reduces the number of endospores
D)increases food nutrient value
E)None of the choices are correct

Question 26

Placing organisms at 4ᵒC is ________.

A)bactericidal
B)bacteristatic
C)decontamination
D)sterilization
E)None of the choices are correct

Question 27

Which of the following forms of radiation is in order from the most penetrating to the least penetrating?

A)Gamma,cathode,X rays
B)Gamma,X rays,cathode
C)Cathode,gamma,X ray
D)Cathode,X ray,gamma
E)X ray,gamma,cathode

Question 28

Sterilization is achieved by ________.

A)flash pasteurization
B)hot water
C)boiling water
D)steam autoclave
E)All of the choices are correct

Question 29

Dry heat ________.

A)is less efficient than moist heat
B)cannot sterilize
C)includes tyndallization
D)is used in devices called autoclaves
E)will sterilize at 121°C for 15 minutes

Question 30

Which of the following items are typically irradiated in order to kill microbes?

A)Meats like ground beef and pork
B)Human tissues such as heart valves and skin
C)Operating room air
D)Surgical gloves
E)All of the choices are correct.

Question 31

________ heat is more rapidly effective and efficient compared to ________ heat.

A)High; dry
B)High; moist
C)Dry; moist
D)Moist; dry
E)Moist; high

Question 32

Vials of microorganisms that undergo the freeze-drying process called ________ will remain preserved and viable for years.

A)desiccation
B)flash freeze
C)lyophilization
D)pasteurization
E)sterilization

Question 33

What instrument is most effective for pressure-temperature sterilization?

A)Oven
B)Autoclave
C)Water bath
D)Bunsen burner
E)Incubator

Question 34

The lowest temperature needed to kill all microbes in 10 minutes is the ________.

A)thermal death point (TDP)
B)thermal death time (TDT)
C)sporicidal time
D)death phase point
E)None of the choices are correct

Question 35

________ radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.

A)Infrared
B)Ultraviolet
C)Gamma
D)Particle
E)Ionizing

Question 36

A method for sterilizing milk,called ________ treatment,uses 134°C for 1 to 2 seconds.

A)pasteurization
B)batch pasteurization
C)flash pasteurization
D)ultra high temperature
E)None of the choices are correct

Question 37

The shortest time required to kill all the microbes in a sample at a specified temperature is called the ________.

A)thermal death point (TDP)
B)thermal death time (TDT)
C)sporicidal time
D)death phase point
E)None of the choices are correct

Question 38

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

A)Ultraviolet (germicidal)light
B)Gamma rays
C)121°C at 15 psi for 15 minutes
D)160°C for 2 hours
E)All of the choices would kill Mycobacterium in a culture tube.

Question 39

Which of the following does not affect microbial nucleic acids?

A)Moist heat
B)Ultraviolet light
C)X rays
D)Ethylene dioxide
E)Formaldehyde

Question 40

The most efficient sterilizing conditions in a steam autoclave are ________.

A)121°C at 15 psi for 15 minutes
B)63°C for 30 minutes
C)160°C for 2 hours
D)71.6°C for 15 seconds
E)100°C for 30 minutes

Question 41

The chemical agent that produces highly toxic and reactive free radicals is ________.

A)cidex
B)cationic detergents
C)hydrogen peroxide
D)chlorhexidine
E)iodophors

Question 42

Antimicrobial agents can target the cell wall by ________.

A)blocking its synthesis
B)digesting it
C)inhibiting peptidoglycan synthesis
D)All of the choices are correct

Question 43

In lab,inoculating loops are sterilized using ________.

A)moist heat
B)chemicals
C)incineration
D)filtration
E)ethylene oxide

Question 44

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for mucous membrane irrigation,obstetrical washes,hand scrubbing,and prepping surgical skin sites is ________.

A)carbolic acid
B)chlorhexidine
C)triclosan.
D)formalin
E)quarternary ammonium compounds

Question 45

All of the following disrupt the cytoplasmic membrane except ________.

A)detergents
B)quaternary ammonium compounds
C)high concentration phenols
D)iodine

Question 46

________ is a control method that removes microorganisms rather than inhibiting or killing them.

A)Boiling
B)Sterilization
C)Radiation
D)Filtration
E)Disinfection

Question 47

Which of the following is not used as an antiseptic?

A)Iodophor
B)Chlorhexidine
C)3% hydrogen peroxide
D)Betadine (povidone-iodine)
E)Glutaraldehyde

Question 48

Hydrogen peroxide can be ________.

A)sporicidal
B)fungicidal
C)bactericidal
D)virucidal
E)All of the choices are correct

Question 49

HEPA filters are used to remove microbes from ________.

A)air
B)liquids
C)human tissues
D)medical instruments
E)All of the choices are correct

Question 50

Which of the following is not a factor that affects germicidal activity?

A)The material being treated
B)The length of exposure
C)The strength of the germicide
D)The microorganism being treated
E)All of these choices are factors.

Question 51

Which of the following acids is not used to destroy or inhibit microbial cells in food?

A)Acetic acid
B)Benzoic acid
C)Lactic acid
D)Phosphoric acid
E)Propionic acid

Question 52

Bacteristatic agents kill bacterial cells.

Question 53

Which of the following represents the use of osmotic pressure as a microbial control method?

A)Bleaching a kitchen counter
B)Salting meat
C)Rinsing a cut with Betadine
D)Both bleaching a kitchen counter and rinsing a cut with Betadine are correct.

Question 54

Ethylene oxide is ________.

A)sporicidal
B)only effective with high heat
C)the active agent in household bleach
D)used as an antiseptic against anaerobes
E)a halogen

Question 55

All of the following pertain to hypochlorites except ________.

A)release hypochlorous acid in solution
B)cause denaturation of enzymes
C)found in iodophors
D)used to disinfect water,restaurant,and medical equipment
E)found in common household bleach

Question 56

Heavy metals work by ________.

A)rupturing the cell membrane
B)inactivating proteins
C)binding to DNA
D)dissolving the cell wall
E)mutating DNA

Question 57

Prions require more extensive methods of sterilization than are needed for bacterial endospores.

Question 58

Microbicidal agents are sterilants.

Question 59

________ is a halogen used in gaseous and liquid form for large-scale disinfection of drinking water and sewage.

A)Iodine
B)Chlorine
C)Bromine
D)Fluorine
E)All of the choices are correct.

Question 60

Alcohols ________.

A)dissolve membrane lipids at concentrations of greater than 50%
B)can be used for disinfection or antisepsis
C)are skin degerming agents
D)are limited in effectiveness due to rapid evaporation
E)All of the choices are correct

Question 61

When a control agent targets the metabolic processes of microbial cells,active younger cells typically die more rapidly than older cells.

Question 62

Temperature and time must be considered when determining susceptibility of microbes to lethal conditions.  At a specific temperature,the thermal death ________ can be determined,alternatively,the thermal death ________ can be assessed as the lowest temperature that will kill a test organism in 10 minutes.

A)time; point
B)point; time
C)exposure,time
D)point; exposure

Question 63

Pasteurization does not kill endospores or thermoduric microbes.

Question 64

Most microbial contaminants of food are killed at freezing temperatures.

Question 65

Which of the following statements is true when comparing moist heat methods of microbial control to dry heat control?

A)Both moist heat and dry heat methods can achieve complete sterilization.
B)Only moist heat (autoclaving)can sterilize objects,dry heat is limited to disinfection.
C)Dry heat is more efficient than moist heat,requiring less time to sterilize objects.
D)Boiling is a more successful method of sterilizing instruments than using a dry heat oven.

Question 66

A microorganism that is not motile and has stopped metabolizing could be considered dead.

Question 67

Analine dyes,like crystal violet,have antimicrobial activity particularly against gram-positive bacteria and some fungi.

Question 68

Chlorine compounds remain stable and effective in the presence of excess organic matter.

Question 69

All of the following are accurate statements concerning microbial control using dry heat except ________.

A)it is the preferred method of control to sterilize cottons,plastics and paper
B)it takes up to 4 hours to sterilize instruments in a hot-air oven,whereas the Bunsen burner will incinerate an inoculating loop almost immediately
C)the Bunsen burner can achieve temperatures up to 1,870ᵒC,whereas the hot-air oven reaches temperatures of up to 180ᵒC
D)while fast and effective,the Bunsen burner is limited to metals and glassware,whereas powders and oils can also be sterilized in the hot-air oven

Question 70

Pseudomonas is resistant to soaps.

Question 71

Alcohols are more effective at inactivating enveloped viruses than naked viruses.

Question 72

Hydrogen peroxide can be used to sterilize instruments such as endoscopes.

Question 73

Ethylene oxide is a sterilizing gas.

Question 74

Soaps and detergents are very effective as sterilants.

Question 75

Isopropyl alcohol wiped across a skin site can sterilize it.

Question 76

Of the six methods of controlling growth by physical means; heat,cold,desiccation,radiation,filtration and osmotic pressure,the only method that is capable of complete sterilization is radiation.

Question 77

Pasteurization will make milk sterile.

Question 78

Ionizing radiation is more effective than nonionizing radiation in killing microbes.

Question 79

The presence of organic matter such as saliva and pus can interfere with the actions of disinfectants.

Question 80

Which pair of physical control methods will achieve complete sterilization?

A)Autoclaving and ionizing radiation
B)Ultraviolet radiation and filtration
C)Freezing and filtration
D)Osmotic pressure and incineration
E)Pasteurization and ultraviolet radiation