What factors need to be considered when choosing a method of microbial control?

A. the site and the environment to be treated

B. the site and environment to be treated, and the susceptibility of the microbes

C. the environment of the site or material to be treated

D. the site or material to be treated

E. the susceptibility of the microbes which must be removed

B

A 100ul sample containing 1000 bacterial cells/ul in log phase growth is added to 9.9ml of fresh culture medium broth. Assuming no nutrients are in limited supply, and a generation time of 30 minutes, how many bacteria will be present in the entire broth culture after six hours?

A. 2.56 x 10 to the 7th

B. 1.2 x 10 to the 6th

C. 6.0 x 10 to the 5th

D. 6.0 x 10 to the sixth

E. 4.096 x 10 to the eigth

E

Which of the following is associated with meiosis but NOT with mitosis?

A. a zygote

B. a spindle

C. a chromatid

D. a centromere

E. a tetrad

E

Air can be disinfected using

A. ultraviolet light

B. ethylene oxide

C. HEPA filters

D. both HEPA filters and ultraviolet light

E. both ethylene oxide and ultraviolet light

D

Functions of the eukaryotic cytoskeleton include giving shape to the cell and

A. anchoring organelles.

B. anchoring organelles and moving cellular contents.

C. separating chromosomes during mitosis.

D. moving cellular contents.

E. anchoring organelles, moving cellular contents, and separating chromosomes during mitosis.

B

Asexual reproduction within a hypha produces

A. sprangiospores.

B. chamydospores

C. zygospores

D. basidiospores

E. ascospores

B

Synthesis of cDNA requires the use of

A. agarose

B. reverse transcriptase.

B. restriction enzymes.

D. fluorescent synthetic nucleotides

E. DNA ligase

B

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

A. hydrostatic pressure

B. salt concentrations

C. pH values

D. carbon dioxide levels

E. oxygen concentrations

A

Most broad-spectrum antibiotics act by

A. inhibiting protein synthesis

B. inhibiting metabolic pathways.

C. inhibiting the synthesis of the cell wall.

D. inhibiting nucleic acid synthesis.

E. disrupting the cytoplasmic membrane.

A

The procedure used to identify individuals by their unique genetic sequences is known as

A. DNA fingerprinting

B. northern analysis

C. xenotransplantation.

D. DNA sequencing.

E. microarray analysis.

A

Which of the following is an accurate description of viruses?

A. They are typically about the size of prokaryotic cells.

B. They are the smallest known cells.

C. They are acellular obligatory parasites.

D. They are composed of protein only.

E. They are visible with a light microscope.

C

Examples of recent accomplishments in the use of recombinant DNA technology include

A. a cure for HIV

B. production of gene modified human embryos.

C. gene therapy to correct an immune system deficiency in humans.

D. production of a peach-apple hybrid plant.

E. production of new emerging disease agents.

C

Drug-resistant populations of microbes arise when

A. exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells.

B. exposure to drugs causes mutations that produce resistance.

C. synergy between medications occurs.

D. resistant cells become numerous in a population due to their greater vigor.

E. the patient becomes immune to the drug.

A

Which of the following is a protozoan with two nuclei and no mitochondria?

A. Euglena

B. Plasmodium

C. Trichomonas

D. Giardia

E. Paramecium

D

Creating conditions in the laboratory that promote the growth of some microbes while inhibiting the growth of others is called

A. transport conditions

B. reducing conditions.

C. complex culturing.

D. selective enrichment culturing.

E. differential culturing.

D

Glutaraldehyde acts on microbes by

A. cross-linking thymidines in DNA.

B. forming chemical cross links in DNA and proteins.

C. disrupting cytoplasmic membranes.

D. inhibiting enzyme activity.

E. denaturing proteins.

B

DNA sequences known as transposons contain

A. palindromes.

B. sigma factor sequences.

C. F+ plasmids.

D. origins.

E. promoters.

A

Naked capsid animal viruses gain entry to host cells by

A. direct penetration.

B. endocytosis.

C. membrane fusion.

D. both endocytosis and direct penetration.

E. endocytosis, direct penetration, and membrane fusion.

D

The process known as _______ is initiated with the incorporation of fMet.

A. DNA replication

B. capping

C. transcription

D. translation

E. light repair

D

A microarray is assembled using

A. reverse transcriptase and DNA polymerase.

B. agarose and nitrocellulose.

C. single-stranded DNA and silicone chips.

D. gold beads and magnets.

E. restriction enzymes.

C

Which of the following statements concerning reduction reactions is FALSE?

A. An electron acceptor becomes more positively charged.

B. They are coupled with oxidation reactons.

C. An electron acceptor gains an electron.

D. They frequently involve electron carrier molecules.

E. A molecule gains a hydrogen atom.

A

A flexible, spiral-shaped bacterium is called a

A. coccobacillus

B. sarcina

C. spirochete.

D. spirillum

E. vibrio.

C

The mechanism of action of the antibiotic vancomycin is

A. inhibition of nucleic acid synthesis.

B. inhibition of protein synthesis.

C. inhibition of a metabolic pathway.

D. inhibition of a cell wall synthesis.

E. disruption of cytoplasmic membranes.

D

Antimicrobial sugar analogs are effective for

A. preventing virus attachment.

B. blocking a metabolic pathway.

C. preventing cell membrane synthesis.

D. preventing bacterial protein synthesis.

E. preventing nucleic acid synthesis

A

One mechanism by which viruses may cause cancer is to interrupt the genetic regulatory sequences of repressor proteins. Which of the following types of viruses is most likely to be involved in causing cancer by this mechanism?

A. +ssRNA viruses

B. dsRNA viruses

C. retroviruses

D. -ssRNA viruses

E. both +ssRNA viruses and -ssRNA viruses

C

What is the correct order for the stages of a lytic replication cycle, from earliest to latest stages?

I. Synthesis

II. Assembly

III. Attachment

IV. Release

V. Entry

A. I, III, V, II, IV

B. III, II, V, I, IV

C. I, II, III, V, IV

D. V, III, II, IV, I

E. III, V, I, II, IV

E

Prokaryotes of the genus Pyrodictium are

A. members of the deeply branching bacteria.

B. intracellular parasites.

C. halophiles.

D. thermophiles.

E. endospore formers.

D

Why is lysogeny advantageous to a bacteriophage?

A. It allows the bacteriophage to destroy the host cell's DNA.

B. It speeds up the viral infection cycle.

C. It allows the bacteriophage to infect cells it would not normally infect.

D. The genetic material of the bacteriophage is amplified many times over that seen in a lytic phage.

E. It enables the bacteriophage to take over the cell.

D

Which of the following statements concerning glycolysis is TRUE?

A. Glycolysis produces ATP by oxidative phosphorylation.

B. Glycolysis occurs in the cell membranes of bacteria.

C. Ribulose 5-phosphate is an intermediate of glycolysis.

D. Glycolysis both requires the input of ATP and produces ATP.

E. Glycolysis is an alternative to fermentation.

D

During ___, a new peptide bond is formed with the amino acid located in the A site.

A. mismatch repair

B. polyadenylation

C. DNA replication elongation

D. transcription elongation

E. translation elongation

E

Antiviral medications can best be descrived as

A. broad spectrum antimicrobials.

B. extremely narrow spectrum synthetic antimicrobials.

C. synthetic antimicrobials.

D. extremely narrow spectrum antimicrobials.

E. antibiotics produced by bacteria.

B

Replacing the defective gene responsible for sickle-cell anemia is an example of

A. genetic screening.

B. producing a transgenic organism.

C. gene therapy.

D. recombinant therapy

E. DNA fingerprinting

C

The mechanism of action of erythromycin is

A. inhibition of a metabolic pathway.

B. inhibition of nucleic synthesis.

C. disruption of cytoplasmic membranes.

D. inhibition of protein synthesis.

E. inhibition of cell wall synthesis.

D

The chemical agents known as "quats" are used for

A. sterilization.

B. antisepsis.

C. quantifying antimicrobial activity.

D. disinfection.

E. neither antisepsis nor disinfection.

D

Which of the following statements is MOST accurate concerning metabolism?

A. Metabolism is the assembly of macromolecules into cellular structures.

B. Metabolism is all the chemical reactions of an organism, both anabolic and catabolic.

C. Metabolism is the assembly of small molecules into macromolecules.

D. Metabolism is the digestion of nutrients to release energy.

E. Metabolism is the production and expenditure of chemical energy.

B

The process of ______ is described as semiconservative.

A. mismatch repair

B. translation

C. transformation

D. DNA replication

E. transcription

D

Which of the following occurs in eukaryotes but NOT in prokaryotes?

A. DNA replication

B. transformation

C. translation

D. transcription

E. polyadenylation

E

The detection of DNA by FISH makes use of

A. reverse transcriptase and DNA polymerase.

B. restriction fragments.

C. compressed air and gold beads.

D. synthetic DNAs and fluorescent tags.

E. DNA polymerase and DNA ligase.

D

The process of incineration is used for

A. disinfection.

B. sterilization.

C. degerming.

D. sanitization.

E. both disinfection and sanitation.

B

The acid-fast stain is used to stain

A. bacteria with capsules.

B. living bacteria.

C. bacteria with waxy cell walls.

D. endospores.

E. bacteria lacking cell walls.

C

A field biologist finds what might be a new species of prokaryote in sewage sludge. It is an obligate anaerobe that metabolized organic acids and requires hydrogen gas. It lacks a peptidoglycan cell wall. The new find may be a

A. methanogen.

B. mycoplasma.

C. clostridium.

D. bacteroides.

E. cyanobacterium.

A

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

A. microaerophile.

B. facultative anaerobe.

C. obligate aerobe.

D. aerotolerant anaerobe.

E. obligate anaerobe.

E

Sister chromatids separate during ____ of meiosis.

A. telophase I

B. prophase II

C. anaphase II

D. anaphase I

E. metaphase II

C

High G + C Gram-positive filamentous bacteria of the genus ____ are capable of metabolizing a diverse range of environmental contaminants.

A. Corynebacterium

B. Rhizobium

C. Nocardia

D. Streptomyces

E. Actinomyces

C

All of the following are associated with ATP molecules EXCEPT

A. three phosphate groups.

B. a recyclable energy supply.

C. a long-term energy supply.

D. formation of coenzymes.

E. high-energy bonds.

C

Robert Koch's contributions to the foundations of modern microbiology include

A. providing evidence for rejecting the theory of spontaneous generation.

B. demonstrating the role of microbes in fermentation.

C. developing methods for isolation and identification of bacteria.

D. demonstrating that hand washing can reduce the spread of disease.

E. demonstrating certain chemicals are toxic to bacteria but not humans.

C

Which of the following processes powers the rotation of the flagella of archaea?

A. a sodium ion gradient

B. ATP

C. assembly and disassembly of microtubules

D. contraction of cytoskeletal proteins

E. a hydrogen ion gradient

B

Disinfecting agents naturally produced by microorganisms are

A. quats

B. triclosans

C. halogens.

D. antimicrobials.

E. aldehydes.

D

The DNA sequence of a portion of gene in a wild-type organism is TTACCATATTCACCC, and the corresponding peptide sequence is TTACCATATTCACCC and the peptide sequence is Leu-Pro-Cys-Ser-Pro. This is an example of a(n) ______ mutation (type) resulting in a _____ mutation (effect).

A. deletion; missense

B. base substitution; missense

C. base substitution; silent

D. base substitution; nonsense

E. insertion; nonsense

B

Which of the following is/are common to chemiosmosis and the light-dependent reactions of photosynthesis?

A. electron transport only

B. reduction of NADP+ only

C. a proton gradient only

D. both electron transport and a proton gradient

E. electron transport, a proton gradient, and reduction of NADP+

D

Several antiviral medications used to treat HIV interfere with

A. cell wall synthesis.

B. assembly of membranes.

C. nucleic acid synthesis.

D. folic acid synthesis.

E. protein synthesis.

C

In conjugation, F+ cells

A. do not have conjugation pili.

B. serve as recipient cells

C. can transfer DNA only to other F+ cells.

D. contain an F plasmid

E. contain "jumping genes"

D

A researcher finds a mutant mouse with a phenotype that may have applications to human disease. What would be the most efficient means of identifying the mutated gene?

A. Use a microarray to identify transcribed genes.

B. Sequence the entire genome of the mutant.

C. Search a mouse gene library.

D. Use DNA fingerprinting to identify an altered DNA fragment, sequence it and search a gene library.

E. Use DNA fingerprinting to identify a DNA fragment of altered size.

D

Which of the following statements regarding virus taxonomy is TRUE?

A. Viruses are classified on the basis of the taxonomy of their host organisms.

B. Some virus family names are derived from the name of an important member of the family.

C. Virus classes are based on the domain of the host organism.

D. The species epithet is a Latin descriptor of the virion structure.

E. Virus classes are well established

B

Host specificity of a virus is due to

A. particular genes that it shares with the infected cell.

B. difference in size between the virus and the host cell.

C. interactions between viral and cellular surface molecules.

D. the presence or absence of a cell wall on the host cell.

E. the presence of an envelope.

C

Bacteria acquire new DNA from the environment in the process of

A. the SOS response.

B. recombination.

C. transposition.

D. conjugation.

E. transformation.

E

The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a Beta-lactamase inhibitor, is known as

A. selective toxicity.

B. synergism.

C. cross resistance.

D. antimetabolism.

E. chemotherapy.

B

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

A. stationary

B. lag

C. death

D. log

E. exponential

B

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

A. degerming agent only.

B. high-level germicide.

C. germistatic agent only.

D. intermediate-level germicide.

E. low-level germicide.

E

How are fungal viruses different from viruses that infect other organisms?

A. They cannot pass through a filter.

B. They have only DNA for genetic material.

C. They have no extracellular state.

D. They have no capsid.

E. They have no intracellular state.

C

Classification of bacteria into different phyla is based on comparisons involving which of the following?

A. cell wall composition

B. protein sequences

C. DNA sequences

D. both DNA and protein sequences

E. DNA and protein sequences, as well as cell wall compostition

D

Gamma irradiation is a process for

A. disinfection.

B. sterilization.

C. degerming.

D. antisepsis.

E. both antisepsis and disinfection.

B

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

A. Mycobacterium bovis

B. Pseudomonas aeruginosa

C. Neisseria gonorrhoeae

D. Clostridium botulinum

E. Bacillus stearothermophilus

E

Which of the following statements concerning fimbriae is TRUE?

A. Fimbriae facilitate the transfer of DNA among bacterial cells.

B. All bacteria have fimbriae.

C. A bacterial cell will usually have only one or two fimbriae.

D. Bacteria use fimbriae to attach to surfaces.

E. Fimbraie are about as long as flagella.

D

Ribavirin is an antiviral that interferes with

A. cell membrane component synthesis.

B. viral attachment.

C. protein synthesis.

D. nucleic acid synthesis.

E. cell wall synthesis

D

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

A. cyclic AMP

B. a repressor portein

C. an inducer

D. glucose

E. an iRNA

E

Which of the following pathways is specifically inhibited by trimethoprim?

A. the conversion of PABA to dihydrofolic acid

B. the conversion of dihydrofolic acid to tetrahydrofolic acid

C. the conversion of PABA to tetrahydrofolic acid

D. the conversion of tetrahydrofolic acid to PABA

E. the conversion of dihydrofolic acid to PABA

B

Which of the following is an accurate description of a virion?

A. the nucleic acid of a viral pathogen

B. a population of infectious particles

C. the protein portion of a viral particle

D. an infectious particle of protein and nucleic acid outside a host cell

E. the nucleic acid of a viral pathogen inside a host cell

D

A unique feature of cytokinesis in algae is

A. the unequal division of the cytoplasm.

B. that cytokinesis is delayed until several rounds of mitosis have occurred.

C. the formation of a cleavage furrow.

D. the new cell is pinched off by a ring of cell wall.

E. the formation of a cell plate between daughter cells.

E

The events of ____ are initiated at sequences called origins.

A. DNA replication

B. transcription

C. splicing

D. translation

E. transposition

A

Injection DNA into cells can be accomplished using

A. silicon chips and nucleic acids.

B. micropipettes.

C. nitrocellulose membranes.

D. compressed air and gold beads.

E. micropipettes, or compressed air and gold beads.

E

Which of the following is an INCORRECT pairing?

A. magnification; refraction of radiation

B. numerical aperature; curved glass

C. contrast; staining techniques

D. electron beams; shorter wavelength

E. dark field; high contrast

B

The therapeutic range of an antimicrobial is the

A. range of concentration at which the antimicrobial is both effective and non-toxic.

B. range of microorganisms the antimicrobial effects.

C. ratio of the concentration of antimicrobial in the blood to the oral dose.

D. ratio of the dose a patient can tolerate to the effective dose.

E. length of time the mediation persists in the body after a single dose.

A

Aerobic free-living Gram-negative bacilli in the phylum Proteobacteria that are capable of metabolizing a wide range of organic compounds are members of the genus

A. Pseudomonas.

B. Salmonella.

C, Vibrio.

D. Cytophagia

E. Rickettsia

A

Cells must be naturally or artificially "competent" for which of the following events to occur?

A. conjugation

B. transposition

C. specialized transduction

D. generalized transduction

E. transformation

E

If a microbiology lab student left the safranin out of the Gram stain procedure, what would be the result?

A. Gram-positive cells would be colorless and Gram-negative cells would be pink.

B. Gram-positive cells would be pink and Gram-negative cells would be purple.

C. All cells would be pink.

D. Gram-positive cells would be purple and Gram-negative cells would be colorless.

E. All cells would be purple.

D

Sigma factors are involved in the regulation of bacterial

A. translation

B. transformation

C. DNA replication

D. transcription

E. mutation repair

D

Which of the following is a target of pasteurization?

A. Clostridium botulinum

B. Chlamydia trachomatis

C. Bacillus stearothermophilus

D. Brucella melitensis

E. Neisseria gonorrhoeae

D

Which of the following is a CORRECT pairing of metabolic terms?

A. hydrolysis: decomposition

B. dehydration: decomposition

C. synthesis: exothermic

D. synthesis: catabolism

E. catabolism: endothermic

A

A sulfonamide and trimethoprim may be administed in combination to

A. reduce development of antibiotic resistance.

B. reduce relative toxicity.

C. provide broad-spectrum action.

D. inhibit multiple metabolic pathways.

E. treat infections with microbes that require folic acid.

A

The "backbone" of the DNA molecule is composed of

A. phosphates.

B. pentoses.

C. alternating phosphates and pentoses.

D. nitrogenous bases.

E. amino acids.

C

The procedure known as "replica plating" is used in

A. the Ames test.

B. negative selection only.

C. positive selection only.

D. both positive and negative selection.

E. mutagenesis

B

Protozoa that move by means of lobe-like pseudopods and lack shells are classified by

A. Euglenozoa

B. Foraminifera.

C. Rhizaria.

D. Amoebozoa.

E. Radiolarians.

D

Anabolic reactions may be characterized as

A. producing ATP

B. breaking large molecules into smaller molecules to produce ATP

C. breaking large molecules into smaller molecules.

D. exergonic

E. forming large molecules from smaller molecules.

E

The metabolic processes called fermentation

A. occur only when oxygen is readily available.

B. produce substrates for glycolysis.

C. are alternatives for the pentose phosphate pathway.

D. use an organic molecule as a final electron pathway.

E. produce substrates for the Krebs cycle.

D

How does resistance to drugs spread in bacterial populations?

A. Both horizontal gene transfer and the growth of biofilms spread drug resistance.

B. Exposure to drugs alters gene expression in bacteria.

C. Exposure to drugs causes mutations in bacterial genes.

D. The formation of biofilms protects bacteria from the effects of drugs.

E. Horizontal gene transfer between bacteria spreads R (resistance) plasmids

A

Codons are recognized by

A. mRNAs

B. tRNAs

C. sigma factors.

D. rRNAs

E. siRNAs

B

Probes used for detecting genetic sequences are frequently composed of

A. plasmids with a marker sequence.

B. silicon chips.

C. synthetic nucleic acids and labeled conjugates, such as fluorescent dyes.

D. gold beads coated with DNA

E. restriction enzymes.

C

Ribozymes are required for

A. translation.

B. RNA splicing.

C. capping.

D. both translation and RNA splicing.

E. capping, RNA splicing and translation

D

The Beta-lactams are narrow spectrum antibacterials because

A. the thick peptiglycan walls prevent their entry into cells.

B. they are analogs for a compound metabolized only by Gram-negative bacteria.

C. the outer membrane prevents their entry into cells.

D. they block a synthetic step unique to the Gram-positive bacteria.

E. they are analogs for a unique cell membrane lipid.

C

In the taxonomic system developed by Linnaeus, _______were classified as Animalia.

A. single-celled Alveolata

B. unicellular algae

C. multicellular fungi

D. both unicellular algae and fungi

E. both unicellular Alveolata and fungi

A

The process of _____ requires the activity of DNA ligase.

A. DNA replication

B. transduction

C. translation

D. transcription

E. capping

A

Silvadene, a topical treatment for burns, contains 1% silver. What category of chemical control agent is in Silvadene?

A. aldehydes

B. surfactants

C. heavy metals

D. oxidizing agents

E. halogens

C

Which of the following produces NADPH?

A. the Embden-Meyerhof pathway only

B. the pentose phosphate pathway only

C. the Entner-Doudoroff pathway only

D. both the Embden-Meyerhof and the Entner-Doudoroff pathways

E. both the pentose phosphate and the Entner-Doudoroff pathways

E

In Southern blotting, DNA molecules are immobilized on

A. nitrocellulose membranes.

B. silicon chips.

C. gold beads.

D. paper.

E. agarose.

A

A researcher has discovered a new metabolic product of a fungus that may have antimicrobial properties. Which methos would be best for preparing the material for tests of its effect on bacteria?

A. auotclaving

B. lyophilization

C. ultraviolet irradiation

D. filtration

E. dilution with alcohol

D