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Chapter 13: Control of Microbial Growth

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Chapter 13: Control of Microbial Growth

28 problems · 0 figures

13-1 §13.MC source ↗

Which of the following types of medical items requires sterilization?
  1. a.
    needles
  2. b.
    bed linens
  3. c.
    respiratory masks
  4. d.
    blood pressure cuffs

Answer

A. needles

13-2 §13.MC source ↗

Which of the following is suitable for use on tissues for microbial control to prevent infection?
  1. a.
    disinfectant
  2. b.
    antiseptic
  3. c.
    sterilant
  4. d.
    water

Answer

B. antiseptic

13-3 §13.MC source ↗

Which biosafety level is appropriate for research with microbes or infectious agents that pose moderate risk to laboratory workers and the community, and are typically indigenous?
  1. a.
    BSL-1
  2. b.
    BSL-2
  3. c.
    BSL-3
  4. d.
    BSL-4

Answer

B. BSL-2

13-4 §13.MC source ↗

Which of the following best describes a microbial control protocol that inhibits the growth of molds and yeast?
  1. a.
    bacteriostatic
  2. b.
    fungicidal
  3. c.
    bactericidal
  4. d.
    fungistatic

Answer

D. fungistatic

13-5 §13.MC source ↗

The decimal reduction time refers to the amount of time it takes to which of the following?
  1. a.
    reduce a microbial population by 10%
  2. b.
    reduce a microbial population by 0.1%
  3. c.
    reduce a microbial population by 90%
  4. d.
    completely eliminate a microbial population

Answer

C. reduce a microbial population by 90%

13-6 §13.MC source ↗

Which of the following methods brings about cell lysis due to cavitation induced by rapid localized pressure changes?
  1. a.
    microwaving
  2. b.
    gamma irradiation
  3. c.
    ultraviolet radiation
  4. d.
    sonication

Answer

D. sonication

13-7 §13.MC source ↗

Which of the following terms is used to describe the time required to kill all of the microbes within a sample at a given temperature?
  1. a.
    D-value
  2. b.
    thermal death point
  3. c.
    thermal death time
  4. d.
    decimal reduction time

Answer

C. thermal death time

13-8 §13.MC source ↗

Which of the following microbial control methods does not actually kill microbes or inhibit their growth but instead removes them physically from samples?
  1. a.
    filtration
  2. b.
    desiccation
  3. c.
    lyophilization
  4. d.
    nonionizing radiation

Answer

A. filtration

13-9 §13.MC source ↗

Which of the following refers to a disinfecting chemical dissolved in alcohol?
  1. a.
    iodophor
  2. b.
    tincture
  3. c.
    phenolic
  4. d.
    peroxygen

Answer

B. tincture

13-10 §13.MC source ↗

Which of the following peroxygens is widely used as a household disinfectant, is inexpensive, and breaks down into water and oxygen gas?
  1. a.
    hydrogen peroxide
  2. b.
    peracetic acid
  3. c.
    benzoyl peroxide
  4. d.
    ozone

Answer

A. hydrogen peroxide

13-11 §13.MC source ↗

Which of the following chemical food preservatives is used in the wine industry but may cause asthmatic reactions in some individuals?
  1. a.
    nitrites
  2. b.
    sulfites
  3. c.
    propionic acid
  4. d.
    benzoic acid

Answer

B. sulfites

13-12 §13.MC source ↗

Bleach is an example of which group of chemicals used for disinfection?
  1. a.
    heavy metals
  2. b.
    halogens
  3. c.
    quats
  4. d.
    bisbiguanides

Answer

B. halogens

13-13 §13.MC source ↗

Which chemical disinfectant works by methylating enzymes and nucleic acids and is known for being toxic and carcinogenic?
  1. a.
    sorbic acid
  2. b.
    triclosan
  3. c.
    formaldehyde
  4. d.
    hexaclorophene

Answer

C. formaldehyde

13-14 §13.MC source ↗

Which type of test is used to determine whether disinfectant solutions actively used in a clinical setting are being used correctly?
  1. a.
    disk-diffusion assay
  2. b.
    phenol coefficient test
  3. c.
    in-use test
  4. d.
    use-dilution test

Answer

C. in-use test

13-15 §13.MC source ↗

The effectiveness of chemical disinfectants has historically been compared to that of which of the following?
  1. a.
    phenol
  2. b.
    ethyl alcohol
  3. c.
    bleach
  4. d.
    formaldehyde

Answer

A. phenol

13-16 §13.MC source ↗

Which of the following refers to a germicide that can kill vegetative cells and certain enveloped viruses but not endospores?
  1. a.
    high-level germicide
  2. b.
    intermediate-level germicide
  3. c.
    low-level germicide
  4. d.
    sterilant

Answer

C. low-level germicide

13-22 §13.FITB source ↗

A medical item that comes into contact with intact skin and does not penetrate sterile tissues or come into contact with mucous membranes is called a(n) ________ item.

Answer

noncritical

13-23 §13.FITB source ↗

The goal of ________ ________ protocols is to rid canned produce of Clostridium botulinum endospores.

Answer

commercial sterilization

13-24 §13.FITB source ↗

In an autoclave, the application of pressure to ________ is increased to allow the steam to achieve temperatures above the boiling point of water.

Answer

steam

13-25 §13.FITB source ↗

Doorknobs and other surfaces in clinical settings are often coated with ________, ________, or ________ to prevent the transmission of microbes.

Answer

copper, nickel, zinc

13-26 §13.FITB source ↗

If a chemical disinfectant is more effective than phenol, then its phenol coefficient would be ________ than 1.0.

Answer

greater

13-27 §13.FITB source ↗

If used for extended periods of time, ________ germicides may lead to sterility.

Answer

high-level

13-28 §13.FITB source ↗

In the disk-diffusion assay, a large zone of inhibition around a disk to which a chemical disinfectant has been applied indicates ________ of the test microbe to the chemical disinfectant.

Answer

susceptibility or sensitivity

13-17 §13.TF source ↗

Sanitization leaves an object free of microbes.

Answer

False

13-18 §13.TF source ↗

Ionizing radiation can penetrate surfaces, but nonionizing radiation cannot.

Answer

True

13-19 §13.TF source ↗

Moist-heat sterilization protocols require the use of higher temperatures for longer periods of time than do dry-heat sterilization protocols do.

Answer

False

13-20 §13.TF source ↗

Soaps are classified as disinfectants.

Answer

False

13-21 §13.TF source ↗

Mercury-based compounds have fallen out of favor for use as preservatives and antiseptics.

Answer

True

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Problems and answers are adapted from Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister and Brian M. Forster, OpenStax, and are used under the CC BY-NC-SA 4.0 licence. Access for free at https://openstax.org/books/microbiology/pages/1-introduction. Illustrations: Copyright Rice University, OpenStax, under CC BY-NC-SA 4.0 license. This adaptation is released under the same licence, is non-commercial, and is neither affiliated with nor endorsed by OpenStax or Rice University.