Deck 11: Physical and Chemical Control of Microbes

Question 1

The alcohol wipe used on a patient's skin before an injection is an example of

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

Answer 1

A

Question 2

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.

Answer 2

E

Question 3

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.

Answer 3

B

Question 4

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

A)naked viruses
B)protozoan cysts
C)fungal spores
D)bacterial endospores
E)yeast

Question 5

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

A)virucide
B)bactericide
C)germicide
D)sporicide
E)fungicide

Question 6

Microbial death occurs when there is

A)no movement.
B)no reproduction.
C)a change in appearance.
D)a decrease in size.
E)All of the choices occur.

Question 7

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

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

Question 8

Physical agents for controlling microbial growth include all of the following except

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

Question 9

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

A)antisepsis.
B)disinfection.
C)sterilization.
D)decontamination.

Question 10

Each of the following is a target of antimicrobial agents except

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

Question 11

The method of removing vegetative microbial life forms and debris to reduce contamination to safe levels is termed

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

Question 12

The easiest microbial forms to kill or inhibit are

A)naked viruses.
B)vegetative bacteria and fungi.
C)endospores.
D)protozoan cysts.
E)mycobacteria and staphylococci.

Question 13

The use of a physical or chemical process to destroy vegetative pathogens on inanimate objects is

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

Question 14

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.

Question 15

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 16

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

A)denature
B)bind
C)dissolve
D)mutate

Question 17

The removal of all life forms from inanimate objects is termed

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

Question 18

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 19

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

A)the number of microorganisms
B)the type of microorganisms present
C)temperature and pH
D)mode and dosage of the agent
E)All of the choices will influence the action.

Question 20

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.

Question 21

Removal of moisture by dehydration is called

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

Question 22

The lowest temperature needed to kill or inactivate all microbes in 10 minutes is the

A)thermal death point (TDP).
B)thermal death time (TDT).
C)sporicidal time.
D)death phase point.

Question 23

Intermittent sterilization,which uses 3 days of lower temperature steam for short periods of time,is also called

A)pasteurization.
B)incubation.
C)tyndallization.
D)disinfection.
E)desiccation.

Question 24

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

A)pasteurization.
B)chlorination.
C)moist heat autoclave.
D)filtration.
E)boiling water.

Question 25

The minimum sterilizing conditions in a steam autoclave are

A)121 ^$\circ$ C at 15 psi for 15 minutes.
B)63 ^$\circ$ C for 30 minutes.
C)160 ^$\circ$ C for 2 hours.
D)71.6 ^$\circ$ C for 15 seconds.
E)100 ^$\circ$ C for 30 minutes.

Question 26

The shortest time required to kill or inactivate 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.

Question 27

_____ 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 28

_____ 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 29

Electrons are ejected from atoms in cells when organisms are exposed to

A)desiccation.
B)ultraviolet light.
C)ethyl alcohol.
D)hydrogen peroxide.
E)gamma rays and X rays.

Question 30

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

A)cured meats
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

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 ^$\circ$ C at 15 psi for 15 minutes
D)160 ^$\circ$ C for 2 hours
E)All of the choices are correct.

Question 32

Which of the following is not a primary target of milk pasteurization?

A)Salmonella
B)Campylobacter jejuni
C)Lactobacillus
D)Listeria monocytogenes
E)Brucella

Question 33

Sterilization is achieved by

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

Question 34

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 ^$\circ$ C for 15 minutes.

Question 35

A method for sterilizing milk,called _____ treatment,uses 134 ^$\circ$ C for 1 to 2 seconds.

A)pasteurization
B)batch pasteurization
C)flash pasteurization
D)ultra high temperature
E)tyndallization

Question 36

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)is used to sterilize food products.

Question 37

Placing organisms at 4^oC is

A)bactericidal.
B)bacteriostatic.
C)decontamination.
D)sterilization.
E)germicidal.

Question 38

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 39

What instrument is most effective for pressure-temperature sterilization?

A)oven
B)autoclave
C)water-bath
D)Bunsen burner
E)incubator

Question 40

Place the following forms of radiation 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 41

Which of the following germicides is/are also sporicidal?

A)Betadine
B)chlorine
C)phenolics
D)chlorhexidine
E)chlorine,chlorhexidine,and Betadine

Question 42

Which of the following is not used as an antiseptic?

A)iodophor
B)chlorhexidine
C)3% hydrogen peroxide
D)merthiolate
E)aqueous glutaraldehyde

Question 43

Which of the following is not a heavy metal?

A)tincture of iodine
B)merthiolate
C)silver nitrate solution
D)zinc
E)mercurochrome

Question 44

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 45

_____ 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)Betadine

Question 46

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is

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

Question 47

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

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

Question 48

_____ solution was introduced in the late 19th century for preventing gonococcal infections in a newborn's eyes after exposure to the mother's infected birth canal.

A)Merthiolate
B)Triclosan
C)Betadine
D)Silver nitrate
E)Zinc oxide

Question 49

Alcohols

A)denature proteins when in a 50-95% alcohol-water solution.
B)disinfect items when soaking method is utilized.
C)are skin degerming agents.
D)at 50% or higher concentrations dissolve cell membrane lipids.
E)All of the choices are correct.

Question 50

Which of the following is not true of glutaraldehyde?

A)is classified as a carcinogen
B)inactivates viruses
C)does not damage plastics
D)cross-links proteins on cell surfaces
E)inactivates endospores in 3 hours

Question 51

Filtration sterilization

A)can remove viruses.
B)relies on gravity.
C)removes toxins.
D)uses heat and filtration.
E)leaves behind endospores.

Question 52

All of the following act as surfactants except

A)detergents.
B)soaps.
C)quaternary ammonia.
D)alcohols.
E)iodine.

Question 53

Hydrogen peroxide is

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

Question 54

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

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

Question 55

Which of the following is not true of chloramines?

A)contain chlorine
B)can sanitize and disinfect
C)form trihalomethanes with organic compounds
D)are safer than free chlorine
E)treat wounds and skin surfaces

Question 56

Iodophors include

A)chloramines.
B)betadine.
C)tincture of iodine.
D)alcohols.
E)chlorhexidine.

Question 57

The chemical agent/s that produce/s highly reactive hydroxyl-free radicals and also decomposes to O₂ gas is

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

Question 58

All of the following are phenols or phenolics except

A)Lysol.
B)hexachlorophene.
C)triclosan.
D)cresols.
E)chlorhexidine.

Question 59

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 60

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 dairy,restaurant,and medical equipment.
E)found in common household bleach.

Question 61

Bacteriostatic agents kill bacterial cells.

Question 62

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

Question 63

The sterilizing gas used in chemiclaves is

A)ethylene oxide.
B)iodophor.
C)glutaraldehyde.
D)formaldehyde.
E)chlorine dioxide.

Question 64

Most microbial contaminants of food are killed or inactivated at freezing temperatures.

Question 65

Which is mismatched?

A)sodium hypochlorite - chlorine
B)iodophor - iodine
C)benzalkonium chloride - quaternary ammonium compound
D)merthiolate - silver
E)formalin - formaldehyde

Question 66

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

Question 67

Pasteurization does not inactivate endospores or thermoduric microbes.

Question 68

Pasteurization is used to sterilize milk.

Question 69

Using a HEPA filter in a vacuum or furnace is an example of which microbial control method?

A)physical method
B)dry method
C)chemical agent
D)gases
E)surfactant

Question 70

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 71

All of the following are alkylating control agents except

A)ethylene oxide.
B)iodophor.
C)glutaraldehyde.
D)formaldehyde.
E)propylene oxide.

Question 72

Microbicidal agents are sterilants.

Question 73

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

Question 74

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

Question 75

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 76

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

A)bleaching a kitchen counter
B)salting of meat
C)rinsing of a cut with Betadine
D)exposing dental equipment to UV light

Question 77

Endospores can be inactivated by

A)dry heat at 170 ^$\circ$ C for 2 hours.
B)incineration.
C)glutaraldehyde for 3 or more hours.
D)ethylene oxide for 3 or more hours.
E)All of the choices are correct.

Question 78

Antimicrobial agents can target the cell wall by

A)blocking its synthesis.
B)digesting it.
C)denaturing proteins.
D)All of the choices are correct.

Question 79

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

Question 80

In lab,inoculating loops are sterilized using

A)moist heat.
B)chemicals.
C)incineration.
D)filtration.
E)gas sterilization.