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Control of Microbial Growth

Total questions: 60

Worksheet time: 30mins

Name
Class
Date
1.

Pasteurization:

a)

Eliminates all vegetative forms of microbes

b)

Destroys pathogens without altering the taste of the food

c)

Sterilizes culture media

d)

Eliminates endospores

2.

Pyrimidine dimers are removed using:

a)

Photolyase

b)

Nucleotide excision repair

c)

the SOS system

d)

All of these

3.

Pyrimidine dimers only occur:

a)

when two adjacent T's stick together

b)

when two adjacent C's stick together

c)

when two adjacent A's stick together

d)

when two adjacent T's OR C's stick together

4.

Soaps and detergents are examples of:

a)

Phenols

b)

Tinctures

c)

Halogens

d)

Surface active agents

5.

At the same temperature and time which treatment would be more effective?

a)

Dry heat

b)

Moist heat

6.

When subjected to heat or antimicrobial chemicals most bacteria usually:

a)

immediately die

b)

accelerate growth into a log phase

c)

form endospores

d)

die at a constant rate

7.

All of the following are food preservatives, except:

a)

Formaldehyde

b)

Sulfur dioxide

c)

Calcium proprionate

d)

Nitrates

8.

The pasteurization technique used for immediate cold-storage products (AKA milk, yogurt, ice cream…) is termed _________________________.

a)

HTST

b)

UHT

c)

Chemical sterilization

d)

Biocidal pasteurization

9.

Which of the following is most resistant to microbial control methods?

a)

Prions

b)

Gram positive bacteria

c)

Gram negative bacteria

d)

Acid-fast bacteria

10.

The most common physical method of microbial control is:

a)

heat

b)

cold

c)

osmotic pressure

d)

filtration

11.

The most effective concentration of alcohol to control bacterial growth is:

a)

50%

b)

70%

c)

100%

d)

85%

12.

The Thermal Death Point is:

a)

the lowest temperature at which all the microbes in a liquid culture will be killed in 10 minutes

b)

the length of time required to kill all bacteria in a liquid culture at a given temperature

c)

the length of time in which 90% of a bacterial population will be killed at a given temperature

d)

the target temperature for autoclaving

13.

All bacteria have 2 thermal death points.

a)

True

b)

False

14.

Which of the following bacteria have 2 thermal death points?

a)

Clostridium tetani

b)

Bacillus megaterium

c)

Bacillus anthracis

d)

All of these.

15.

Using a highly concentrated bacteriostatic can cause bacterial death.

a)

True

b)

False

16.

The sticky carbohydrate-based component of a biofilm that allows bacteria to resist the actions of disinfectants is termed the _______________________.

a)

Cell wall

b)

Ribosome

c)

Nucleoid

d)

Glycocalyx

17.

The term that means free from microbes is:

a)

septic

b)

aseptic

c)

microstatic

d)

clean

18.

Filtration is used to:

a)

Remove microbes from air

b)

Sterilize heat sensitive solutions

c)

Filter out bacteria, viruses, and even large proteins

d)

All of the these

19.

Dimers are produced by:

a)

UV radiation

b)

Alcohol

c)

Antibiotics

d)

ATP synthase

20.

Bacteria are more sensitive to acidic environments than fungi.

a)

True

b)

False

21.

Which of the following would be expected to influence the effectiveness of an antimicrobial treatment?

a)

Number of microbes present

b)

Presence of organic matter

c)

The length of time the microbes are exposed to the treatment

d)

All of these

22.

Nonionizing radiation at a wavelength of _______nm damages DNA by creating ___________.

a)

130; thymine dimers

b)

130; guanine dimers

c)

260; guanine dimers

d)

260; thymine dimers

23.

Which disinfectant was the LEAST effective against Staphylococcus?

a)

A

b)

B

c)

C

d)

D

24.

____________________ organisms are those that survive pasteurization processes.

a)

pasteurogenic

b)

thermoduric

c)

tolerant

d)

pathogenic

25.

Boiling at ___________ kills most endospores of bacterial pathogens, many viruses, and fungi within 10 mins.

a)

37C

b)

25C

c)

100C

d)

200C

26.

Antimicrobial agents are generally made more effective by:

a)

high pH

b)

low temperature

c)

high temperature

d)

presence of organic matter

27.

Heavy metals (Ag, Hg, Cu, Zn) and their compounds work by ________________.

a)

oligodynamic action

b)

denaturation

c)

lysing the cell membrane

d)

both oligodynamic action & denaturation

28.

Salts and sugars can be used to preserve foods because they cause:

a)

osmotic plasmolysis

b)

osmotic lysis

c)

acidosis

d)

alkalosis

29.

O-phenylphenol, hexachlorphene, and triclosan are all examples of:

a)

phenols

b)

alcohols

c)

halogens

d)

surface-active agents

30.

Which of the following methods would be most likely to kill endospores?

a)

boiling

b)

autoclaving

c)

disinfecting

d)

filtration

31.

Alcohol evaporates quickly. This is called:

a)

volatility

b)

disintegration

c)

degeneracy

d)

antisepsis

32.

Nosocomial infections are those acquired from:

a)

hospitals

b)

nursing homes

c)

outpatient clinics

d)

all of these

33.

Ana is at a restaurant and finds dried food on her fork. What method of disinfection should have been completed?

a)

sanitization

b)

antisepsis

c)

biocide

d)

commercial sterilization

34.

Before injecting a patient, you should __________ the skin.

a)

disinfect

b)

degerm

c)

sanitize

d)

sterilize

35.

Eric is adding a fungicide to his pool. His goal is to ______ fungus.

a)

limit

b)

stop growth of

c)

kill

d)

increase growth of

36.

In most cases, once a bacteriostatic agent is removed, growth will resume.

a)

True

b)

False

37.

Alcohol is a bacteriostatic agent.

a)

True

b)

False

38.

Alcohol is both a disinfectant and an antiseptic.

a)

True

b)

False

39.

In order to effectively kill endospores, virus particles, and fungi, autoclaves must:

a)

Reach 121ºC at 15 psi for 30 min

b)

Reach 121ºC at 15 psi for 15 min

c)

Reach 150ºC at 25 psi for 30 min

d)

Reach 150ºC at 15 psi for 15 min

40.

Michelle wants to clean a dirty toilet. She should probably use a:

a)

disinfectant

b)

degermer

c)

antiseptic

d)

biocide

41.

Before surgery, Gary needs to complete a skin-prep with Betadine. This is a form of:

a)

antisepsis

b)

disinfection

c)

antibiotic

d)

stasis

42.

Which of the following does NOT achieve sterilization?

a)

dry heat

b)

pasteurization

c)

autoclave

d)

supercritical fluids

43.

Which of the following results in lethal damage to nucleic acids?

a)

heat

b)

radiation

c)

certain chemicals

d)

all of these

44.

Gram positive organisms are more resistant to control agents than Gram negative.

a)

True

b)

False

45.

Soap can be used as a surface active agent because it:

a)

Degerms and emulsifies lipids

b)

Uses anions to react with the plasma membrane

c)

Uses cations to denature proteins

d)

Contains quats

46.

What is the only way to be sure that all microbes have been destroyed?

a)

Sterilization

b)

Disinfection

c)

Antisepsis

d)

Incineration

47.

In the ____________________ method, filter paper disks are soaked in a chemical and placed on a culture to evaluate the efficacy of chemical agents.

a)

Paul Ehrlich

b)

Kinyoun

c)

Use-Dilution

d)

Disk-Diffusion

48.

The symbol indicates that ___________ has been used to reduce microbes.

a)

Desiccation

b)

Irradiation

c)

Pressurization

d)

Pasteurization

49.

When bacterial populations are heated, they usually die at a constant rate of 90% per minute. If 1,000,000 microbes are heated for 2 minutes, how many remain?

a)

100,000 microbes

b)

10,000 microbes

c)

1,000 microbes

d)

100 microbes

50.

Refrigeration and incubation are both:

a)

Long-term preservation techniques

b)

Short-term preservation techniques

51.

Low temperatures are:

a)

bactericidal

b)

bacteriostatic

52.

Best treatment for swimming pool bacteria?

a)

chlorine

b)

o-phenylphenol

c)

chlorhexidine

d)

sulfur dioxide

53.

Oldest known antiseptic (ex: betadine)

a)

iodine

b)

chlorine

c)

chlorine dioxide

d)

triclosan

54.

Used to prevent mold growth in cosmetics:

a)

hexachlorophere

b)

aldehyde

c)

organic acids

d)

iodine

55.

All-purpose cleaner found in Lysol:

a)

O-phenylphenol

b)

iodine

c)

chlorine dioxide

d)

bleach

56.

Prevents the souring of wine:

a)

sulfur dioxide

b)

hexachlorophere

c)

iodine

d)

aldehydes

57.

Erica is scrubbing-up before surgery. She should use:

a)

Chlorhexidine

b)

Hexachlorophere

c)

Iodine

d)

Alcohol

58.

KiddieAcademy is planning on sanitizing the playroom. Which is the best disinfectant?

a)

triclosan

b)

chlorhexidine

c)

hexachlorphene

d)

aldehyde

59.

Used to fumigate large buildings:

a)

aldehyde

b)

plasma sterilization

c)

chlorine dioxide

d)

sulfur dioxide

60.

Used for embalming:

a)

bleach

b)

triclosan

c)

aldehydes

d)

tetracycline