Deck 11: Physical and Chemical Control of Microbes

Question 1

Which of the following does not affect microbial nucleic acids?

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

Answer 1

A

Question 2

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

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

Answer 2

A

Question 3

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

Answer 3

A

Question 4

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 5

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

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

Question 6

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 7

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 8

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 9

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 10

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 11

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

Question 12

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

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

Question 13

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) mutate
B) bind
C) dissolve
D) denature

Question 14

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 15

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 16

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 17

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 18

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 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 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 21

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 22

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 23

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 are correct.

Question 24

Removal of moisture by dehydration is called ______.

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

Question 25

_____ radiation excites atoms to a higher energy state within molecules such as DNA,which leads to the formation of pyrimidine dimers.

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

Question 26

Which of the following forms of radiation are 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) X ray, gamma, cathode
E) Cathode, X ray, gamma

Question 27

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 28

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 29

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 30

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 31

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 32

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) tyndallization

Question 33

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

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

Question 34

Placing organisms at 4^oC is ______.

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

Question 35

The minimum sterilizing conditions in a steam autoclave are

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

Question 36

Sterilization is achieved by

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

Question 37

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 38

_____ 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 39

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 40

What instrument is most effective for pressure-temperature sterilization?

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

Question 41

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 42

All of the following act as surfactants except ______.

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

Question 43

Which of the following is not true of chloramines?

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

Question 44

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

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

Question 45

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

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

Question 46

_____ 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 47

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) a quaternary ammonium compound
B) carbolic acid
C) triclosan
D) formalin
E) chlorhexidine

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) Silver nitrate
C) Triclosan
D) Zinc oxide
E) Betadine

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

Heavy metals work by

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

Question 51

Which of the following germicides is/are also sporicidal?

A) Betadine
B) Chlorine
C) Phenolics
D) Chlorhexidine
E) All of these except phenolics.

Question 52

The use of filtration for sterilization

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

Question 53

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 54

Iodophors include ______.

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

Question 55

Hydrogen peroxide is

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

Question 56

All of the following are phenols or phenolics except ______.

A) hexachlorophene
B) Zephiran
C) cresols
D) triclosan
E) Lysol

Question 57

Which of the following is not used as an antiseptic?

A) Iodophor
B) Aqueous glutaraldehyde
C) 3% hydrogen peroxide
D) Chlorhexidine
E) Merthiolate

Question 58

Which of the following is not true of glutaraldehyde?

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

Question 59

Which of the following is not a heavy metal?

A) Tincture of iodine
B) Merthiolate
C) Silver nitrate solution
D) Zinc
E) Mercurochrome

Question 60

All of the following pertain to hypochlorites except

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

Question 61

Pasteurization is used to sterilize milk.

Question 62

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

Question 63

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

A) Surfactant
B) Gases
C) Chemical agent
D) Dry control

Question 64

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

A) Exposing dental equipment to UV light
B) Bleaching a kitchen counter
C) Salting of meat
D) Rinsing of a cut with Betadine

Question 65

Endospores can be inactivated by

A) dry heat at 170°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 66

In lab,inoculating loops are sterilized using ______.

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

Question 67

All of the following are alkylating control agents except ______.

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

Question 68

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

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

Question 69

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 70

All microbicidal agents are sterilants.

Question 71

Bacteriostatic agents kill bacterial cells.

Question 72

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

Question 73

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

Question 74

The sterilizing gas used in chemiclaves is ______.

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

Question 75

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

Question 76

Pasteurization does not inactivate endospores or thermoduric microbes.

Question 77

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

Question 78

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

Question 79

Which is mismatched?

A) Iodophor - iodine
B) Sodium hypochlorite - chlorine
C) Merthiolate - silver
D) Benzalkonium chloride - quaternary ammonium compound
E) Formalin - formaldehyde

Question 80

Ethylene oxide is

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