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Quiz on Biology 2420 Medical Microbiology Test 2, created by bconstance on 10/12/2014.

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Biology 2420 Medical Microbiology Test 2

Question 1 of 165

1

In microbiology the term growth usually refers to an increase in

Select one of the following:

  • a microbe's size.

  • the number of microbial cells.

  • the amount of ATP produced.

  • the number and size of microbial cells.

  • the number and size of microbial cells and the amount of ATP produced.

Explanation

Question 2 of 165

1

A cell that uses an organic carbon source and obtains energy from light would be called a

Select one of the following:

  • photoheterotroph

  • lithoautotroph

  • photoautotroph

  • chemoheterotroph.

  • chemoautotroph

Explanation

Question 3 of 165

1

A(n) ______________ organism is one that requires oxygen for growth.

Select one of the following:

  • anaerobic

  • facultative anaerobic

  • aerotolerant

  • obligate aerobic

  • both aerotolerant and anaerobic

Explanation

Question 4 of 165

1

An aquatic microbe that can grow only at the surface of the water is probably which of the following?

Select one of the following:

  • a phototroph

  • a heterotroph

  • a chemotroph

  • a lithotroph

  • an anaerobe

Explanation

Question 5 of 165

1

Which of the following forms of oxygen is detoxified by the enzyme catalase?

Select one of the following:

  • singlet oxygen

  • hydroxyl radical

  • peroxide anion

  • superoxide radical

  • molecular oxygen

Explanation

Question 6 of 165

1

All of the following are used to protect organisms from the toxic by-products of oxygen EXCEPT

Select one of the following:

  • carotenoids.

  • superoxide dismutase

  • peroxidase

  • protease.

  • catalase.

Explanation

Question 7 of 165

1

A microbe that grows only at the bottom of a tube of thioglycollate is probably a(n)

Select one of the following:

  • obligate aerobe.

  • facultative anaerobe.

  • aerotolerant anaerobe.

  • microaerophile.

  • obligate anaerobe.

Explanation

Question 8 of 165

1

Nitrogen is growth limiting nutrient for many organisms because

Select one of the following:

  • it is necessary for the biosynthesis of amino acids

  • it is required for synthesis of nucleotides.

  • it is required for lipid synthesis.

  • only a small number of bacteria are able to extract it from the atmosphere.

  • only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis.

Explanation

Question 9 of 165

1

Which of the following growth factors would NOT be required by microbes which do not utilize electron transport chains?

Select one of the following:

  • heme.

  • selenium.

  • NADH.

  • vitamins.

  • amino acids.

Explanation

Question 10 of 165

1

At temperatures higher than the maximum growth temperature for an organism,

Select one of the following:

  • proteins are permanently denatured.

  • membranes become too fluid for proper function.

  • hydrogen bonds within molecules are broken.

  • hydrogen bonds are broken, and proteins are proteins are permanently denatured.

  • hydrogen bonds are broken, proteins are denatured, and membranes becomes too fluid.

Explanation

Question 11 of 165

1

Human pathogens are classified as

Select one of the following:

  • thermoduric.

  • thermophiles.

  • mesophiles.

  • hyperthermophiles.

  • psychrophiles.

Explanation

Question 12 of 165

1

The term barophile refers to which of the following growth requirements?

Select one of the following:

  • hydrostatic pressure

  • temperature

  • nitrogen source

  • pH

  • osmotic pressure

Explanation

Question 13 of 165

1

Which of the following organisms would be most likely to contaminate a jar of pickles?

Select one of the following:

  • a neutrophile

  • a thermophile

  • an acidophile

  • an obligate anaerobe

  • a mesophile

Explanation

Question 14 of 165

1

Organisms that can grow with or without oxygen present are

Select one of the following:

  • obligate aerobes.

  • facultative anaerobes.

  • aerotolerant anaerobes.

  • obligate anaerobes.

  • either facultative anaerobes or aerotolerant anaerobes.

Explanation

Question 15 of 165

1

A fastidious organism might be grown on which of the following types of media?

Select one of the following:

  • transport media

  • reducing media

  • enriched media

  • differential media

  • selective media

Explanation

Question 16 of 165

1

Obligate anaerobes may be cultured in the laboratory

Select one of the following:

  • in a reducing medium

  • in a candle

  • in standard Petri plates.

  • on blood agar plates

  • on blood agar plates in a candle jar.

Explanation

Question 17 of 165

1

Joan wants to discover a microbe capable of degrading an environmental contaminant. Which of the following refers to the process she should use?

Select one of the following:

  • chemostat

  • quorum sensing

  • enrichment culture

  • nitrogen fixation

Explanation

Question 18 of 165

1

A microbiologist inoculates a growth medium with 100 bacterial cells/ml. If the generation time of the species is 1 hour, and there is no lag phase, how long will it be before the culture contains more than 10,000 cells/ml?

Select one of the following:

  • 24 hours

  • 7 hours

  • 2 hours

  • 3 hours

  • 10 hours

Explanation

Question 19 of 165

1

An epidemiologist is investigating a new disease and observes what appear to be bacteria inside tissue cells in clinical samples from victims. The scientist wants to try to isolate the bacteria in the lab. What culture conditions are most likely to be successful?

Select one of the following:

  • culturing on blood agar plates

  • inoculation of EMB plates

  • incubation in a candle jar

  • inoculation of cell cultures

  • inoculation of a minimal medium broth

Explanation

Question 20 of 165

1

Which of the following measurement techniques would be useful to quantify a species of bacteria that is difficult to culture?

Select one of the following:

  • membrane filtration

  • viable plate counts

  • MPN

  • microscopic counts

  • metabolic activity

Explanation

Question 21 of 165

1

MacConkey agar plates represent __________ medium.

Select one of the following:

  • a minimal

  • a selective

  • a differential

  • both a differential and a selective

  • both a minimal and a selective

Explanation

Question 22 of 165

1

A Petroff-Hauser counting chamber is

Select one of the following:

  • a glass slide containing an etched grid for counting microbes directly using a microscope.

  • a device that counts cells as they interrupt an electrical current.

  • a device that measures the amount of light that passes through a culture.

  • an apparatus that traps bacterial cells on a membrane filter where they can be counted.

  • a device used to count numbers of bacterial colonies on a Petri plate.

Explanation

Question 23 of 165

1

Another term for the logarithmic growth of bacterial cells is

Select one of the following:

  • generation time.

  • exponential growth.

  • arithmetic growth.

  • absorbance.

  • binary fission.

Explanation

Question 24 of 165

1

A device that removes wastes and adds fresh medium to bacterial cultures in order to prolong the log phase of a culture is called a(n)

Select one of the following:

  • Coulter counter.

  • cytometer.

  • spectrophotometer.

  • pellicle.

  • chemostat.

Explanation

Question 25 of 165

1

A specimen of urine is determined to contain 30 bacterial cells per microliter. How many cells would be present in a milliliter?

Select one of the following:

  • 3

  • 300

  • 30,000

  • 3,000

  • 30 million

Explanation

Question 26 of 165

1

Which of the following is NOT a direct method for measuring the number of microbes in a sample?

Select one of the following:

  • viable plate counts

  • turbidity

  • Coulter counter

  • MPN

  • membrane filtration

Explanation

Question 27 of 165

1

During which growth phase are bacteria more susceptible to antimicrobial drugs?

Select one of the following:

  • lag phase

  • log phase

  • stationary phase

  • death phase

  • the susceptibility is the same for all phases

Explanation

Question 28 of 165

1

The use of salt and sugar in preserving various types of foods is an application of which of the following concepts?

Select one of the following:

  • nitrogen fixation

  • osmotic pressure

  • pH

  • hydrostatic pressure

  • quorum sensing

Explanation

Question 29 of 165

1

A clinical sample labeled as "sputum" was collected from

Select one of the following:

  • the skin.

  • the blood

  • the central nervous system.

  • a piece of tissue.

  • the lungs.

Explanation

Question 30 of 165

1

The method of obtaining isolated cultures that utilizes surface area to dilute specimens is called

Select one of the following:

  • the pour-plate technique.

  • serial dilution.

  • the streak-plate technique.

  • transport media.

  • enrichment culturing.

Explanation

Question 31 of 165

1

__________ are complex communities of various types of microbes that adhere to surfaces.

Select one of the following:

  • Aggregates

  • Colonies

  • Isolates

  • Biofilms

  • Media

Explanation

Question 32 of 165

1

A colony-forming unit is the number of cells

Select one of the following:

  • in a colony.

  • that produces one colony.

  • in a particular specimen.

  • that is in exponential phase in a culture.

  • that can be placed on a Petri plate.

Explanation

Question 33 of 165

1

All of the following ingredients might be found in complex media EXCEPT

Select one of the following:

  • hydrogen peroxide.

  • yeast extract.

  • blood

  • soy extract.

  • milk proteins.

Explanation

Question 34 of 165

1

Sodium thioglycollate is associated with which of the following types of media?

Select one of the following:

  • transport media

  • differential media

  • complex media

  • reducing media

  • selective media

Explanation

Question 35 of 165

1

Which of the following quantification techniques can distinguish living cells from dead cells in a culture?

Select one of the following:

  • microscopic counts

  • dry weight

  • metabolic activity

  • a Coulter counter

  • turbidity

Explanation

Question 36 of 165

1

During the __________ of growth, new cells are being produced at the same rate as other cells are dying.

Select one of the following:

  • lag phase

  • log phase

  • death phase

  • stationary phase

  • intermediate phase

Explanation

Question 37 of 165

1

During the __________ of growth, cells are dying faster than new cells are being produced.

Select one of the following:

  • death phase

  • lag phase

  • log phase

  • stationary phase

  • longitudinal phase

Explanation

Question 38 of 165

1

When cells are metabolically active but not dividing, they are in the

Select one of the following:

  • stationary phase.

  • log phase.

  • lag phase.

  • death phase.

  • exponential phase.

Explanation

Question 39 of 165

1

Metabolic activity is at maximum level in the __________ of growth.

Select one of the following:

  • lag phase

  • log phase

  • death phase

  • stationary phase

  • intermediate phase

Explanation

Question 40 of 165

1

Cells are rapidly growing and dividing during the __________ of growth.

Select one of the following:

  • death phase

  • lag phase

  • log phase

  • stationary phase

  • indeterminate phase

Explanation

Question 41 of 165

1

An organism that tolerates high __________ is called a halophile.

Select one of the following:

  • hydrostatic pressure

  • salt concentrations

  • pH

  • carbon dioxide levels

  • oxygen levels

Explanation

Question 42 of 165

1

A capnophile is a microorganism that thrives in conditions of high __________.

Select one of the following:

  • carbon dioxide levels

  • hydrostatic pressure

  • oxygen levels

  • pH

  • salt concentration

Explanation

Question 43 of 165

1

A microorganism found living under conditions of high __________ is a barophile.

Select one of the following:

  • pH values

  • oxygen concentrations

  • hydrostatic pressure

  • carbon dioxide levels

  • salt concentrations

Explanation

Question 44 of 165

1

Microaerophiles are microbes that grow best at low

Select one of the following:

  • carbon dioxide levels.

  • pH values

  • hydrostatic pressure.

  • oxygen levels.

  • salt concentrations.

Explanation

Question 45 of 165

1

An acidophile thrives under conditions of low

Select one of the following:

  • carbon dioxide levels.

  • salt concentrations.

  • oxygen levels.

  • hydrostatic pressure.

  • pH

Explanation

Question 46 of 165

1

All of the following are associated with nucleic acid structure EXCEPT

Select one of the following:

  • ribose

  • hydrogen bonds.

  • uracil

  • ionic bonds.

  • phosphate

Explanation

Question 47 of 165

1

Which of the following is found at the 5 end of a DNA strand?

Select one of the following:

  • a phosphate group

  • a hydrogen bond

  • a hydroxyl group

  • histones

  • a methyl group

Explanation

Question 48 of 165

1

The bacterial chromosome is

Select one of the following:

  • usually circular.

  • found in a nucleoid

  • found in a nucleus.

  • both circular and found in a nucleoid.

  • both circular and found in a nucleus.

Explanation

Question 49 of 165

1

Which of the following types of plasmids allows a bacterial cell to kill its competitors?

Select one of the following:

  • virulence factors

  • fertility factors

  • bacteriocin factors

  • resistance factors

  • cryptic plasmids

Explanation

Question 50 of 165

1

Which of the following is NOT involved the packaging of eukaryotic chromosomes?

Select one of the following:

  • nucleosomes

  • histones

  • heterochromatin

  • euchromatin

  • Okazaki fragments

Explanation

Question 51 of 165

1

Which of the following statements is true of bacterial plasmids?

Select one of the following:

  • They are found in the nucleoid.

  • They can replicate autonomously

  • They carry genes for essential metabolic functions.

  • They are small circular DNA molecules.

  • They are small circular DNA molecules that can replicate autonomously.

Explanation

Question 52 of 165

1

DNA helicases

Select one of the following:

  • break hydrogen bonds between complementary nucleotides.

  • synthesize short DNA molecules important for the function of DNA polymerase.

  • seal gaps between DNA fragments.

  • proofread DNA molecules.

  • assist in recognition of promoters during transcription.

Explanation

Question 53 of 165

1

Which of the following statements concerning transcription in bacteria is FALSE?

Select one of the following:

  • It occurs in the nucleoid region.

  • Sigma factors are parts of RNA polymerase that recognize promoter regions.

  • The same RNA polymerase transcribes primer RNA, mRNA, tRNA, and rRNA.

  • Termination is either self-induced or due to the presence of Rho protein.

  • There are a variety of sigma factors that affect transcription.

Explanation

Question 54 of 165

1

Which of the following is involved in translation?

Select one of the following:

  • rRNA

  • tRNA

  • mRNA

  • both mRNA and tRNA

  • mRNA, rRNA and tRNA are all involved.

Explanation

Question 55 of 165

1

Which of the following is a characteristic shared by DNA and RNA polymerases?

Select one of the following:

  • efficiency of proofreading

  • type of nucleotides used

  • direction of polymerization

  • speed

  • dependence on helicase

Explanation

Question 56 of 165

1

Which of the following is the strongest base pair?

Select one of the following:

  • guanine-cytosine

  • adenine-uracil

  • adenine-thymine

  • guanine-thymine

  • both adenine-uracil and adenine-thymine

Explanation

Question 57 of 165

1

A codon is a particular combination of three nucleotides. Therefore, there are __________ possible combinations of the nucleotides A, C, G, and T.

Select one of the following:

  • 16

  • 4

  • 12

  • 64

  • 32

Explanation

Question 58 of 165

1

The AUG codon functions in coding for the amino acid methionine and as a

Select one of the following:

  • termination signal.

  • start signal

  • "wobble" codon.

  • marker for introns

  • recognition site for RNA polymerase

Explanation

Question 59 of 165

1

Which of the following must be removed from a eukaryotic mRNA molecule before it can be translated?

Select one of the following:

  • promoter

  • exon

  • intron

  • anticodon

  • codon

Explanation

Question 60 of 165

1

A charged tRNA first enters the ribosomal __________ site and then moves into the __________ site.

Select one of the following:

  • A, E

  • P, A

  • P, E

  • A, P

  • E, A

Explanation

Question 61 of 165

1

Which of the following statements regarding eukaryotic transcription is FALSE?

Select one of the following:

  • Transcription occurs in the nucleus, mitochondria, and chloroplasts (if present).

  • Multiple transcription factors are required.

  • There are four different RNA polymerases.

  • Multiple elongation factors are required.

  • A guanine is added to the 3 end, and a poly-A tail is added to the 5 end of the mRNA transcript.

Explanation

Question 62 of 165

1

Semiconservative DNA replication means that

Select one of the following:

  • each daughter DNA molecule is composed of one original strand and one new strand.

  • nucleotides are constantly being recycled as cells make DNA.

  • the cell can proofread its newly synthesized DNA only part of the time.

  • the sequence of a DNA molecule is preserved as it is being replicated.

  • each strand of a double-stranded DNA molecule is replicated differently.

Explanation

Question 63 of 165

1

Which of the following is NOT a characteristic of Okazaki fragments?

Select one of the following:

  • They are checked for accuracy by DNA polymerase III.

  • They make up the lagging strand of replicated DNA.

  • They begin with an RNA primer.

  • They are joined together by DNA ligase.

  • They are longer in eukaryotic cells.

Explanation

Question 64 of 165

1

The proofreading function of DNA polymerase III results in an error rate of __________ during DNA replication.

Select one of the following:

  • 1 error in 1,000 bases

  • 1 error in 100,000 bases

  • 1 error in 1 million bases

  • 1 error in 10 million bases

  • 1 error in 10 billion bases

Explanation

Question 65 of 165

1

Which of the following processes is involved in the "central dogma" of genetics?

Select one of the following:

  • translation

  • transcription

  • DNA replication

  • transcription and translation

  • DNA replication and translation

Explanation

Question 66 of 165

1

Inducible operons

Select one of the following:

  • are active in the presence of a repressor

  • are generally anabolic pathways

  • are normally active

  • usually require an activator to be transcribed.

  • usually require a repressor to be transcribed.

Explanation

Question 67 of 165

1

Which of the following are considered to be frameshift mutations?

Select one of the following:

  • insertions

  • inversions

  • deletions

  • both inversion and insertion

  • both deletions and insertions

Explanation

Question 68 of 165

1

If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a

Select one of the following:

  • silent mutation

  • nonsense mutation

  • frameshift mutation

  • gross mutation

  • missense mutation

Explanation

Question 69 of 165

1

Which of the following causes mutations by creating thymine dimers?

Select one of the following:

  • nucleotide analogs

  • nitrous acid

  • ultraviolet light

  • benzopyrene

  • gamma rays

Explanation

Question 70 of 165

1

DNA damage caused by ethidium bromide results in __________ mutations.

Select one of the following:

  • insertion

  • substitution

  • deletion

  • both inversion and insertion

  • both insertion and deletion

Explanation

Question 71 of 165

1

Which of the following is a DNA repair enzyme activated by visible light?

Select one of the following:

  • transposase

  • DNA photolyase

  • bacteriocin

  • DNA ligase

  • primase

Explanation

Question 72 of 165

1

The Ames test proves that a chemical is

Select one of the following:

  • carcinogenic

  • carcinogenic in Salmonella

  • mutagenic in Salmonella

  • carcinogenic in humans

  • mutagenic in humans

Explanation

Question 73 of 165

1

The horizontal transfer process known as transduction

Select one of the following:

  • involves a virus

  • involves a pilus

  • requires a cell to be "competent"

  • requires a plasmid

  • involves a mutagen

Explanation

Question 74 of 165

1

Frederick Griffith discovered

Select one of the following:

  • transformation

  • transposons

  • the lac operon

  • DNA

  • conjugation

Explanation

Question 75 of 165

1

In conjugation, F+ cells

Select one of the following:

  • serve as recipient cells

  • contain an F plasmid

  • do not have conjugation pili

  • can transfer DNA only to other F+ cells

  • contain "jumping genes"

Explanation

Question 76 of 165

1

Another term for the palindromic sequence found at the ends of transposons is a(n)

Select one of the following:

  • complex

  • bacteriophage

  • insertion sequence

  • inverted repeat

  • transposase

Explanation

Question 77 of 165

1

Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes?

Select one of the following:

  • histones

  • circular chromosomes

  • linear chromosomes

  • enclosed in nuclear membrane

  • typically consist of a few to several chromosomes

Explanation

Question 78 of 165

1

Genes are active in a region of the eukaryotic chromosome called

Select one of the following:

  • heterochromatin

  • the histone

  • the nucleoid

  • the plasmid

  • euchromatin

Explanation

Question 79 of 165

1

The energy required for DNA replication comes from

Select one of the following:

  • DNA polymerase

  • triphosphate deoxyribonucleotides

  • DNA ligase

  • RNA primer

  • the leading strand

Explanation

Question 80 of 165

1

Which of the following is NOT involved in the regulation of the lac operon?

Select one of the following:

  • an inducer

  • a repressor protein

  • an iRNA

  • glucose

  • cyclic AMP

Explanation

Question 81 of 165

1

Genetic elements known as promoters are initiation points in the process of

Select one of the following:

  • DNA replication

  • transcription

  • translation

  • mutation repair

  • transformation

Explanation

Question 82 of 165

1

Codons are recognized during

Select one of the following:

  • translation

  • transcription

  • base excision

  • DNA replication

  • transduction

Explanation

Question 83 of 165

1

__________ is initiated at sequences called origins

Select one of the following:

  • DNA replication

  • translation

  • splicing

  • transcription

  • transposition

Explanation

Question 84 of 165

1

The process of __________ requires the activity of DNA ligase.

Select one of the following:

  • translation

  • capping

  • transcription

  • DNA replication

  • transduction

Explanation

Question 85 of 165

1

RNA polymerase is primarily responsible for

Select one of the following:

  • DNA replication

  • translation

  • transcription

  • transformation

  • polyadenylation

Explanation

Question 86 of 165

1

The process of __________ requires participation of tRNA molecules

Select one of the following:

  • DNA replication

  • capping

  • transduction

  • translation

  • dark repair

Explanation

Question 87 of 165

1

The process of __________ is initiated with the incorporation of fMet.

Select one of the following:

  • translation

  • transcription

  • capping

  • DNA replication

  • light repair

Explanation

Question 88 of 165

1

Initiation of __________ involves Sigma factor molecules.

Select one of the following:

  • DNA replication

  • translation

  • transcription

  • splicing

  • termination

Explanation

Question 89 of 165

1

The process of __________ is described as semiconservative.

Select one of the following:

  • translation

  • transcription

  • mismatch repair

  • transformation

  • DNA replication

Explanation

Question 90 of 165

1

During __________, the growing polymer is located in the P site.

Select one of the following:

  • polyadenylation

  • DNA replication

  • mismatch repair

  • transcription

  • translation

Explanation

Question 91 of 165

1

Standard methods of sterilization are not effective in inactivating

Select one of the following:

  • viruses

  • bacterial cells

  • prions

  • bacterial endospores

  • fungi

Explanation

Question 92 of 165

1

Which of the following statements is true of disinfectants?

Select one of the following:

  • Disinfectants are effective in destroying endospores.

  • Disinfectants are used on living tissue.

  • Disinfectants are used for sterilization

  • Disinfectants are used on inanimate surfaces.

  • Disinfectants are only effective for short periods of time (seconds to minutes).

Explanation

Question 93 of 165

1

Which of the following statements concerning microbial death is FALSE?

Select one of the following:

  • It can be used to evaluate the efficacy of antimicrobial agents.

  • It is constant over time of exposure to an antimicrobial agent.

  • It is the permanent loss of a microbe's reproductive ability.

  • It is the permanent loss of a microbe's ability to reproduce and can be used to evaluate antimicrobial agents

  • It is not an effective means of evaluating the efficacy of antimicrobial agents.

Explanation

Question 94 of 165

1

Which of the following is an example of sanitization?

Select one of the following:

  • A public toilet is treated with disinfectants.

  • A surgeon washes her hands before surgery

  • Heat is used to kill potential pathogens in apple juice.

  • An autoclave is used to prepare nutrient agar.

  • A nurse prepares an injection site with an alcohol swab.

Explanation

Question 95 of 165

1

Aseptic means

Select one of the following:

  • sterile

  • free of all microbes

  • clean

  • sanitized

  • free of pathogens

Explanation

Question 96 of 165

1

Which of the following would NOT be bacteriostatic?

Select one of the following:

  • desiccation

  • freezing below 0 degrees Celsius

  • lyophilization

  • autoclaving

  • refrigeration of mesophiles

Explanation

Question 97 of 165

1

Antimicrobial agents that damage nucleic acids also affect

Select one of the following:

  • the cell wall

  • the cell membrane

  • the viral envelope

  • endospores

  • protein synthesis

Explanation

Question 98 of 165

1

Seventy percent alcohol is effective against

Select one of the following:

  • enveloped viruses

  • noneveloped viruses

  • bacterial endospores

  • protozoan cysts

  • prions

Explanation

Question 99 of 165

1

An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)

Select one of the following:

  • high-level germicide

  • low-level germicide.

  • intermediate-level germicide.

  • degerming agent only.

  • germistatic agent only.

Explanation

Question 100 of 165

1

Which of the following is NOT an effective means of sterilization?

Select one of the following:

  • ionizing radiation

  • incineration

  • lyophilization

  • autoclaving

  • dry heat

Explanation

Question 101 of 165

1

Which of the following describes flash pasteurization?

Select one of the following:

  • heating at 63°C for 30 minutes

  • heating at 72°C for 15 seconds

  • heating at 72°C for 15 minutes

  • heating at 134°C for one second

  • passing liquid through steam at 140°C

Explanation

Question 102 of 165

1

The dairy creamer used in restaurants is usually sterilized by

Select one of the following:

  • filtration

  • ionizing radiation

  • lyophilization

  • UHT sterilization

  • autoclaving

Explanation

Question 103 of 165

1

Boiling water for 10 minutes is effective in ridding it of

Select one of the following:

  • actively growing bacteria

  • enveloped viruses

  • bacterial endospores

  • protozoan cysts

  • both growing bacteria and enveloped viruses

Explanation

Question 104 of 165

1

Which of the following is NOT a feature associated with filtration?

Select one of the following:

  • nitrocellulose or plastic membrane filters

  • sterilization of heat-sensitive materials

  • varying thicknesses of membrane filters used

  • use of HEPA filters to filter air

  • ability of some filters to trap viruses and proteins

Explanation

Question 105 of 165

1

Which of the following is a target of pasteurization?

Select one of the following:

  • Bacillus stearothermophilus

  • Clostridium botulinum

  • Neisseria gonorrhoeae

  • Chlamydia trachomatis

  • Brucella melitensis

Explanation

Question 106 of 165

1

Which of the following types of radiation is nonionizing and has the shortest wavelength?

Select one of the following:

  • ultraviolet light

  • infrared radiation

  • microwaves

  • X rays

  • gamma rays

Explanation

Question 107 of 165

1

Which of the following is used for microbial control in fresh fruits and vegetables?

Select one of the following:

  • X rays

  • ultraviolet

  • electron beams

  • microwaves

  • gamma rays

Explanation

Question 108 of 165

1

Which of the following can be used to disinfect air?

Select one of the following:

  • HEPA filters

  • ethylene oxide

  • ultraviolet light

  • both HEPA and ultraviolet light

  • both ethylene oxide and ultraviolet light

Explanation

Question 109 of 165

1

Lysol is an example of which of the following groups of chemical antimicrobial agents?

Select one of the following:

  • halogens

  • phenolics

  • alcohols

  • aldehydes

  • surfactants

Explanation

Question 110 of 165

1

Which of the following is the most appropriate pairing of microbe and biosafety level?

Select one of the following:

  • E. coli, BSL-3

  • anthrax, BSL-1

  • Ebola, BSL-2

  • methicillin-resistant Staphylococcus aureus (MRSA), BSL-2

  • tuberculosis, BSL-1

Explanation

Question 111 of 165

1

Betadine is an example of which of the following groups of antimicrobial agents?

Select one of the following:

  • alcohols

  • heavy metals

  • halogens

  • phenolics

  • surfactants

Explanation

Question 112 of 165

1

Which of the following statements about quaternary ammonium compounds is FALSE?

Select one of the following:

  • They are a type of detergent.

  • Zephiran is an example of a quat.

  • They are not effective against Pseudomonas aeruginosa.

  • They function by cross-linking proteins.

  • They are harmless to humans except at high concentrations.

Explanation

Question 113 of 165

1

Which of the following is a sterilizing agent?

Select one of the following:

  • ozone

  • hydrogen peroxide

  • peracetic acid

  • dish soap

  • ozone and hydrogen peroxide

Explanation

Question 114 of 165

1

Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?

Select one of the following:

  • hydrogen peroxide

  • beta-propiolactone

  • thimerosal

  • hexachlorophene

  • silver nitrate

Explanation

Question 115 of 165

1

Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water?

Select one of the following:

  • ethylene oxide

  • formaldehyde

  • hydrogen peroxide

  • calcium hypochlorite

  • triclosan

Explanation

Question 116 of 165

1

Which of the following statements about aldehydes is FALSE?

Select one of the following:

  • They are used only to preserve dead tissues.

  • They denature proteins.

  • Some aldehydes can sterilize after long periods of exposure.

  • They are usually hazardous to humans.

  • They are used in aqueous solutions.

Explanation

Question 117 of 165

1

Disinfecting agents naturally produced by microorganisms are

Select one of the following:

  • aldehydes

  • antimicrobials.

  • halogens

  • quats

  • triclosans

Explanation

Question 118 of 165

1

A chemical agent that kills pathogenic microbes in general is a(n)

Select one of the following:

  • sanitizer

  • germicide

  • disinfectant

  • fungicide

  • antiseptic

Explanation

Question 119 of 165

1

Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?

Select one of the following:

  • It is inexpensive

  • It is stable during storage

  • It is harmless to humans

  • It only arrests grows of vegetative cells.

  • It acts quickly

Explanation

Question 120 of 165

1

The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?

Select one of the following:

  • Clostridium botulinum

  • Neisseria gonorrhoeae

  • Bacillus stearothermophilus

  • Pseudomonas aeruginosa

  • Mycobacterium bovis

Explanation

Question 121 of 165

1

A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?

Select one of the following:

  • autoclaving

  • filtration

  • dilution with alcohol

  • lyophilization

  • ultraviolet irradiation

Explanation

Question 122 of 165

1

Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?

Select one of the following:

  • use-dilution test

  • microbial death rate

  • in-use test

  • thermal death point

  • phenol coefficient

Explanation

Question 123 of 165

1

Which of the following would be used to sterilize a mattress?

Select one of the following:

  • autoclaving

  • formaldehyde

  • ethylene oxide

  • heavy metals

  • radiation

Explanation

Question 124 of 165

1

Disinfectants that damage membranes include

Select one of the following:

  • alcohol

  • phenolics

  • iodine

  • hydrogen peroxide

  • both alcohol and phenolics

Explanation

Question 125 of 165

1

Which of the following antimicrobial agents is the most toxic to humans?

Select one of the following:

  • 70 % alcohol

  • ethylene oxide

  • quats

  • chloramines

  • iodophors

Explanation

Question 126 of 165

1

The process of filtration is a(n)

Select one of the following:

  • disinfectant method.

  • sterilizing method.

  • sanitization method.

  • antiseptic procedure.

  • ineffective method for removing microbes.

Explanation

Question 127 of 165

1

Hydrogen peroxide is a(n)

Select one of the following:

  • sterilizing agent.

  • disinfecting agent.

  • antiseptic.

  • disinfecting and sterilizing agent.

  • ineffective method of disinfecting.

Explanation

Question 128 of 165

1

The process of incineration is used for

Select one of the following:

  • sterilization

  • disinfection

  • sanitization

  • both disinfection and sanitization

  • degerming

Explanation

Question 129 of 165

1

Alcohols are used for

Select one of the following:

  • disinfection.

  • sterilization.

  • antisepsis.

  • both sterilization and disinfection.

  • both antisepsis and disinfection.

Explanation

Question 130 of 165

1

The chemical agents known as "quats" are used for

Select one of the following:

  • antisepsis

  • disinfection

  • sterilization

  • quantifying antimicrobial activity

  • neither antisepsis nor disinfection

Explanation

Question 131 of 165

1

The compound ethylene oxide is used in

Select one of the following:

  • sanitization.

  • sterilization.

  • antisepsis.

  • degerming.

  • disinfection.

Explanation

Question 132 of 165

1

Glutaraldehyde is used for

Select one of the following:

  • antisepsis.

  • disinfection.

  • sterilization

  • sanitization.

  • both disinfection and sterilization.

Explanation

Question 133 of 165

1

__________ may be achieved using chlorine dioxide.

Select one of the following:

  • Disinfection

  • Sterilization

  • Degerming

  • Antisepsis

  • Both antisepsis and degerming

Explanation

Question 134 of 165

1

Gamma irradiation is a process for

Select one of the following:

  • sterilization.

  • disinfection.

  • antisepsis.

  • degerming.

  • both antisepsis and disinfection.

Explanation

Question 135 of 165

1

__________ can be accomplished using boiling water.

Select one of the following:

  • Sanitization

  • Disinfection

  • Sterilization

  • Antisepsis

  • Both disinfection and sanitization

Explanation

Question 136 of 165

1

Obligate anaerobes have enzymes such as superoxide dismutase to protect them from the damaging effects of oxygen.

Select one of the following:

  • True
  • False

Explanation

Question 137 of 165

1

Nitrogen fixation is a process that occurs in all bacteria.

Select one of the following:

  • True
  • False

Explanation

Question 138 of 165

1

Thermoduric mesophiles are often responsible for spoilage of improperly canned foods.

Select one of the following:

  • True
  • False

Explanation

Question 139 of 165

1

An obligate halophile will burst if placed in freshwater.

Select one of the following:

  • True
  • False

Explanation

Question 140 of 165

1

The only effective way to store bacterial cultures for short periods of time is to arrest their metabolism by freezing.

Select one of the following:

  • True
  • False

Explanation

Question 141 of 165

1

Quorum sensing is a process by which bacteria respond to the density of other bacteria in their environment.

Select one of the following:

  • True
  • False

Explanation

Question 142 of 165

1

An obligate anaerobe can be cultured in a candle jar.

Select one of the following:

  • True
  • False

Explanation

Question 143 of 165

1

Agar is a useful compound in the microbiology lab because it is an excellent nutrient for bacteria.

Select one of the following:

  • True
  • False

Explanation

Question 144 of 165

1

A selective medium can be formulated either by including inhibitory chemical substances or by leaving out a single crucial nutrient.

Select one of the following:

  • True
  • False

Explanation

Question 145 of 165

1

In spectrophotometry, 40% light transmission is the same thing as 60% absorbance of light.

Select one of the following:

  • True
  • False

Explanation

Question 146 of 165

1

Prokaryotic cells are diploid.

Select one of the following:

  • True
  • False

Explanation

Question 147 of 165

1

Prokaryotes have one type of DNA polymerase, which is different from that of eukaryotes.

Select one of the following:

  • True
  • False

Explanation

Question 148 of 165

1

The most common type of mutation is a point mutation.

Select one of the following:

  • True
  • False

Explanation

Question 149 of 165

1

Most bacteria have a natural ability to take up DNA from their environment.

Select one of the following:

  • True
  • False

Explanation

Question 150 of 165

1

The structure of DNA explains both its ability to encode genetic information and the way in which it is copied during cell reproduction.

Select one of the following:

  • True
  • False

Explanation

Question 151 of 165

1

DNA, which is negatively charged, wraps around positively charged histones as part of the packaging of eukaryotic chromosomes.

Select one of the following:

  • True
  • False

Explanation

Question 152 of 165

1

Bidirectional replication means that each strand of a DNA molecule is replicated in the opposite direction from the other.

Select one of the following:

  • True
  • False

Explanation

Question 153 of 165

1

The phenotype of an organism reflects only part of its genotype.

Select one of the following:

  • True
  • False

Explanation

Question 154 of 165

1

In generalized transduction, viruses carry random DNA sequences from one cell to another.

Select one of the following:

  • True
  • False

Explanation

Question 155 of 165

1

DNA polymerase III participates in the dark repair mechanism of DNA mutation repair.

Select one of the following:

  • True
  • False

Explanation

Question 156 of 165

1

An environment may contain some microbes and still be considered sterile.

Select one of the following:

  • True
  • False

Explanation

Question 157 of 165

1

Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.

Select one of the following:

  • True
  • False

Explanation

Question 158 of 165

1

UV light has the most effect on protein structure.

Select one of the following:

  • True
  • False

Explanation

Question 159 of 165

1

Antimicrobial agents usually work best at high temperatures and pH levels.

Select one of the following:

  • True
  • False

Explanation

Question 160 of 165

1

The phenol coefficient is one of the most widely used measurements of an antimicrobial agent's effectiveness.

Select one of the following:

  • True
  • False

Explanation

Question 161 of 165

1

No chemical or antimicrobial agents inactivate prions.

Select one of the following:

  • True
  • False

Explanation

Question 162 of 165

1

The decimal reduction time is the time required to kill all the microbes in a given sample.

Select one of the following:

  • True
  • False

Explanation

Question 163 of 165

1

Slow freezing is more damaging to microbial cells than quick freezing.

Select one of the following:

  • True
  • False

Explanation

Question 164 of 165

1

Hydrogen peroxide is an effective antiseptic.

Select one of the following:

  • True
  • False

Explanation

Question 165 of 165

1

By themselves, soaps have only degerming activity, not antimicrobial activity.

Select one of the following:

  • True
  • False

Explanation