Microbiology Module 2

An aquatic microbe that can grow only near the surface of the water is probably which of the following? A. a phototroph B. a heterotroph C. a chemotroph D. a lithotroph E. an anaerobe

A. a phototroph

Which of the following defines a heterotroph? A. an organism that must obtain its carbon in an organic form B. an organism that does not require essential nutrients for growth C. an organism that uses CO as its carbon source D. an organism that produces all the trace elements it requires for growth E. an organism that uses CO as its carbon source

A. an organism that must obtain its carbon in an organic form

Formation of peptide bonds between amino acids to build a polypeptide would be called A. anabolism. B. phosphorylation. C. fermentation. D. exergonic. E. glycolysis.

A. anabolism.

Which of the following has been approved by the Department of Agriculture to be sprayed on livestock to prevent food infection? A. bacteriophages B. oncoviruses C. adenoviruses D. variola E. parvovirus

A. bacteriophages

What is viewed as a nearly perfect system for viral propagation? A. bird embryos B. white mice C. guinea pigs D. humans E. white rabbits

A. bird embryos

An organism that requires chemical nutrients which serve as final electron acceptors is a(n) A. chemotroph. B. phototroph. C. lithotroph. D. autotroph. E. aerobe.

A. chemotroph.

Blood agar plates are an example of ________ medium. A. differential B. selective C. reducing D. defined E. transport

A. differential

Most bacteriophages contain what type of nucleic acid? A. double-stranded DNA B. double-stranded RNA C. single-stranded DNA D. double-stranded DNA/RNA hybrid E. single-stranded RNA

A. double-stranded DNA

Obligate anaerobes may be cultured in the laboratory A. in a reducing medium. B. in a standard incubator. C. in standard Petri plates. D. on blood agar plates. E. in standard complex media.

A. in a reducing medium.

The most stable environment for cells exists in what type of solution? A. isotonic B. hypotonic C. saprobic D. pressurized E. hypertonic

A. isotonic

For most microbes, environmental factors fundamentally affect the function of what? A. metabolic enzymes B. nucleic acids C. lipids D. polysaccharides E. cell membranes

A. metabolic enzymes

The viral envelope performs all but which of the following functions? A. neutralization of the virus B. protection of the viral nucleic acid C. binding to the host cell surface D. assisting in penetration of the viral nucleic acid E. stimulation of the host immune response

A. neutralization of the virus

Which method is not used to grow animal viruses? A. nutrient agar B. tissue culture C. live animals D. chicken eggs E. duck eggs

A. nutrient agar

Enzymes that catalyze moving a phosphate from one substrate to another are called A. phosphotransferases. B. oxidoreductases. C. decarboxylases. D. aminotransferases. E. ligases.

A. phosphotransferases.

In the process of ________, microbes detect the presence and density of other microbes and modify their metabolic activity in response. A. quorum sensing B. antagonism C. mutualism D. symbiosis E. synergy

A. quorum sensing

Which of the following methods provides information about the number of living cells in a sample of bacterial culture? A. serial dilution and viable plate count B. membrane filtration C. a Petroff-Hauser counting chamber D. flow cytometry E. a Coulter counter

A. serial dilution and viable plate count

What term is defined as an interrelationship between two or more free-living organisms that is beneficial to both but not necessary for the survival of either? A. synergism B. mutualism C. commensalism D. parasitism E. antagonism

A. synergism

What statement regarding bacteria in the exponential phase of growth is incorrect? A. they do not influence the course of an infection B. they are more susceptible to antimicrobial agents C. they are more numerous and virulent than bacterial in the later growth phases D. they are more likely to be passed from an infected patient to others E. they will show their natural size and correct reaction when stained

A. they do not influence the course of an infection

Important components of coenzymes are A. vitamins. B. metallic ions. C. active sites. D. substrates. E. ribozymes.

A. vitamins.

Molecules that satisfy heterotrophic nutritional requirements include all but which of the following? A. water B. nucleic acids C. lipids D. carbohydrates E. proteins

A. water

A microbiologist inoculates a flask of broth with 1 ml of 100 bacterial cells/ml. 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 6,000 cells/ml? A. 12 hours B. 6 hours C. 2 hours D. 4 hours E. 10 hours

B. 6 hours

Which organism is an example of a photoautotroph? A. protozoa B. algae C. fungi D. pathogenic bacteria E. animals

B. algae

What type of virus has a polyhedral head, a helical tail, and fibers for host cell attachment? A. helical B. bacteriophages C. icosahedral D. enveloped E. naked

B. bacteriophages

Reactants are converted to products by.. A. enzymes releasing energy. B. breaking and forming bonds. C. enzymes binding to reactants. D. reactants releasing energy.

B. breaking and forming bonds.

The membrane receptors that animal viruses typically attach to are actually what? A. virions B. glycoproteins C. capsids D. lipopolysaccharides E. cell walls

B. glycoproteins

The limitation in the scope of hosts an animal virus can infect is known as what? A. tropism B. host range C. adsorption D. latency E. exocytosis

B. host range

During which growth phase are bacteria more susceptible to antimicrobial drugs? A. lag phase B. log phase C. stationary phase D. death phase E. The susceptibility is the same for all phases.

B. log phase

Substances required by living organisms in relatively large quantities and which play principle roles in cell structure and metabolism are known as what? A. nutrients B. macronutrients C. micronutrients D. trace elements E. reservoirs

B. macronutrients

A type of cofactor would be A. vitamins. B. metallic ions. C. active sites. D. substrates. E. ribozymes.

B. metallic ions.

The use of salt and sugar in preserving various types of foods is an application of which of the following concepts? A. nitrogen fixation B. osmotic pressure C. pH D. hydrostatic pressure E. quorum sensing

B. osmotic pressure

Enzymes that catalyze removing electrons from one substrate and adding electrons to another are called A. phosphotransferases. B. oxidoreductases. C. decarboxylases. D. aminotransferases. E. ligases.

B. oxidoreductases.

Enzymes are A. broken down in reactions that require energy input. B. proteins that function as catalysts. C. used up in chemical reactions. D. not needed for catabolic reactions. E. All of these choices are correct.

B. proteins that function as catalysts.

What step in the viral multiplication cycle is defined as the copying and expression of the viral genome by the host's synthetic equipment? A. adsorption B. replication C. assembly and maturation D. release

B. replication

Which is incorrect about viroids? A. they have RNA B. they have a capsid C. they are smaller than ordinary viruses D. they infect citrus trees E. they are plant pathogens

B. they have a capsid

The more successful of the parasitic microorganisms have what type of effect on their host? A. they share energy sources with their host. B. they have no fatal effects on the host and eventually evolve to a less harmful relationship with the host C. they eventually kill the host cell. D. they have no effect whatsoever on the host cell E. they cause an infection when the host is compromised

B. they have no fatal effects on the host and eventually evolve to a less harmful relationship with the host

Which of the following describes anaerobic organisms? A. they use gaseous oxygen in their metabolism B. they lack the enzymes that use oxygen in metabolism, and they lack the enzymes that process toxic oxygen products C. they possess superoxide dismutase but not catalase or peroxidase D. they posses the enzymes needed to process toxic oxygen products E. they metabolize by aerobic respiration when oxygen is present but undergo anaerobic respiration in the absence of oxygen

B. they lack the enzymes that use oxygen in metabolism, and they lack the enzymes that process toxic oxygen products

Which of the following is not a property of the carrier proteins that participate in facilitated diffusion? A. they are present in the cell membrane B. they require the expenditure of energy in order to function C. they exhibit specificity D. they can become saturated E. they exhibit competition

B. they require the expenditure of energy in order to function

At the very minimum, a virus must carry genes for all but which of the following functions? A. mature virus packaging B. transcription of RNA to DNA C. viral capsid synthesis D. host regulation E. synthesis of viral

B. transcription of RNA to DNA.

Which of the following is an indirect method for estimating the number of microbes in a sample? A. viable plate counts B. turbidity C. Coulter counter D. MPN E. membrane filtration

B. turbidity

The ________ method provides an estimate of the CFUs (colony-forming units) in a sample. A. Coulter-counter B. viable plate-count C. streak-plate D. turbidity E. direct microscopic count

B. viable plate-count

What is not a characteristic of viruses? A. viruses are obligate intracellular parasites. B. viruses are active both inside and outside of host cells. C. viruses can infect bacteria, protozoa, fungi, algae, plants, and animals. D. viruses exhibit high specificity for their respective host.

B. viruses are active both inside and outside of host cells.

Which of the following statements is CORRECT regarding Figure 6.1? A. Cells are actively growing only during the stage represented by B. B. No cells are reproducing during the stage represented by D. C. Cells are are most susceptible to antibiotics during the stage represented by A. D. Cells are alive but not reproducing during the stage represented by A. E. No new cells are being produced during the stage represented by C.

C. Cells are are most susceptible to antibiotics during the stage represented by A.

Which of the following organisms would be most likely to contaminate a jar of pickles? A. a neutrophile B. a thermophile C. an acidophile D. an obligate anaerobe E. a mesophile

C. an acidophile

Bacteria divide by a process known as what? A. budding B. snapping division C. binary fission D. zygote fusion E. endospore formation

C. binary fission

Collectively, viruses can contain all but what type of nucleic acid? A. double-stranded DNA B. double-stranded RNA C. double-stranded DNA/RNA hybrid D. single-stranded DNA E. single-stranded RNA

C. double-stranded DNA/RNA hybrid

A fastidious organism might be grown on which of the following types of media? A. transport media B. reducing media C. enriched media D. differential media E. selective media

C. enriched media

The cell's metabolic reactions involve the participation of _____ that lower the activation energy needed for the initiation of a reaction. A. cofactors B. vitamins C. enzymes D. ATP E. Coenzymes

C. enzymes

The ________ of a population is the time it takes for the cells to double in number. A. binary fission B. exponential growth C. generation time D. arithmetic growth E. log phase

C. generation time

The primary sources of nitrogen for heterotrophs include all except which of the following? A. proteins B. DNA C. glucose D. RNA E. amino acids

C. glucose

An apoenzyme A. is part of a simple enzyme. B. is also called a coenzyme. C. is the protein part of a holoenzyme. D. is often an inorganic metal ion. E. is an RNA molecule.

C. is the protein part of a holoenzyme.

What does the nucleic acid of an animal virus do immediately upon entry into the host cell? A. it duplicates itself B. it becomes uncoated C. it alters the genetic expression of the host and instructs it to synthesize building blocks for new viruses D. it causes the host cell to round up and produce inclusion bodies in the cytoplasm E. it causes the host cell to enlarge and form multinucleated giant cells

C. it alters the genetic expression of the host and instructs it to synthesize building blocks for new viruses

When cells are metabolically active but not dividing, they are in the ________ phase. A. stationary B. log C. lag D. death E. exponential

C. lag

The generation time of bacterial cells is shortest during the ________ phase. A. death B. lag C. log D. stationary E. longitudinal

C. log

The growth of bacterial cultures is best described as A. arithmetic growth. B. lag growth. C. logarithmic growth. D. cell division. E. replication.

C. logarithmic growth.

Human pathogens are classified as A. thermoduric B. thermophiles C. mesophiles D. hyperthermophiles E. psychrophiles

C. mesophiles

Nitrogen is required for the production of what category of molecules? A. fatty acids B. phospholipids C. nucleotides D. carbohydrate E. cellulose

C. nucleotides

An organism that produces catalase enzyme is protected from the harmful effects of A. singlet oxygen (1O2). B. hydroxyl radical (HO.). C. peroxide anion (O22-). D. superoxide radical (O2-). E. molecular oxygen (O2).

C. peroxide anion (O22-).

The earth would gradually fill up with organic material, and nutrients would not be recycled if it were not for what group of organisms? A. parasites B. methanogens C. saprobes D. photoautotrophs E. lithoautotrophs

C. saprobes

Which of the following does not contribute to the initiation of the stationary phase of bacterial growth? A. depletion of nutrients and oxygen B. accumulation of organic acids C. the generation time of the dividing organisms D. a drop in the pH of the growth medium E. increased density of the organisms

C. the generation time of the dividing organisms

The method of obtaining isolated cultures that utilizes surface area to physically dilute specimens is called A. the pour-plate technique. B. serial dilution. C. the streak-plate technique. D. transport media. E. enrichment culturing.

C. the streak-plate technique.

________ are complex communities of various types of microbes that adhere to surfaces. A. Aggregates B. Colonies C. Isolates D. Biofilms E. Media

D. Biofilms

The events of binary fission areI. the cell doubles in sizeII. the DNA is replicatedIII. the cell forms a septumIV. the cell separates from its offspring The correct order of these events is A. I, III, II, IV. B. II, III, I, IV. C. IV, I, III, II. D. II, I, III, IV. E. I, II, IV, III.

D. II, I, III, IV.

The principal energy-yielding reaction in animals, most protozoa and fungi, and aerobic bacteria is known as what? A. anaerobic respiration B. fermentation C. photosynthesis D. aerobic respiration E. methanogenesis

D. aerobic respiration

Extremophiles are most commonly what type of microorganism? A. algae B. protozoa C. yeasts D. archaea E. molds

D. archaea

MacConkey agar plates represent ________ medium. A. a minimal B. a selective C. a differential D. both a differential and a selective E. both a minimal and a selective

D. both a differential and a selective

Ribozymes are A. ribosomes which catalyze reactions. B. unique to prokaryotes. C. unique to eukaryotes. D. catalysts for RNA editing. E. catalysts for DNA splicing.

D. catalysts for RNA editing.

A holoenzyme is a combination of a protein and one or more substances called A. substrates. B. apoenzymes. C. catalysts. D. cofactors.

D. cofactors.

Joan wants to discover a microbe capable of degrading an environmental contaminant. Which of the following culturing methods would be most effective for isolation of such an organism? A. cell culture B. chemostat C. quorum sensing D. enrichment culture E. differential culture

D. enrichment culture

Enzymes that are only produced when substrate is present are termed A. exoenzymes B. endoenzymes. C. constitutive enzymes. D. induced enzymes. E. conjugated enzymes.

D. induced enzymes.

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? A. culturing on blood agar plates B. inoculation of EMB plates C. incubation in an anaerobic culture system D. inoculation of cell cultures E. inoculation of a minimal medium broth

D. inoculation of cell cultures

What is not a role of hydrogen within cells? A. it is a major element in all organic compounds B. it serves as the source of free energy in reduction-oxidation reactions C. it forms hydrogen bonds between molecules D. it determines the shape and stability of proteins by forming disulfide bonds E. it maintains pH within the cell

D. it determines the shape and stability of proteins by forming disulfide bonds

The condition in which the host cell chromosome carries bacteriophage DNA is known as what? A. temperate B. prophage C. lysis D. lysogeny E. mutation

D. lysogeny

Which term refers to all of the chemical reactions of the cell? A. catabolism B. redox reactions C. phosphorylation D. metabolism E. cellular respiration

D. metabolism

The combination of a viral nucleic acid plus the viral capsid is known as what? A. capsomers B. envelope C. phage D. nucleocapsid E. prophage

D. nucleocapsid

A(n) ________ organism require(s) oxygen for growth. A. anaerobic B. facultative anaerobic C. aerotolerant D. obligate aerobic E. aerotolerant and an anaerobic

D. obligate aerobic

Microorganisms that are sometimes found growing in jellies, syrups, and brines are known as what? A. acidophiles B. halophiles C. neutrophiles D. osmophiles E. barophiles

D. osmophiles

"Mad cow disease" is the result of infection of cattle with what agent? A. bacteria B. viruses C. viroids D. prions E. delta agents

D. prions

Oncoviruses cause transformed cells to exhibit all but which of the following? A. increased rate of growth B. alterations in chromosomes C. changes in the cell's surface molecules D. production of reverse transcriptase E. capacity to divide for an indefinite period

D. production of reverse transcriptase

All of the following are used to protect organisms from the toxic by-products of oxygen except A. carotenoids. B. superoxide dismutase. C. peroxidase. D. protease. E. catalase.

D. protease.

What types of media are commonly used to isolate anaerobic microbes? A. defined media B. differential media C. complex media D. reducing media E. selective media

D. reducing media

The main criteria used to group viruses are structure, chemical composition, and what other characteristic? A. type of capsid B. overall viral size C. area of host cell in which the virus multiplies D. similarities in genetic makeup E. presence and type of envelope

D. similarities in genetic makeup

Rates of cell production and cell death are approximately equal during the ________ phase of growth. A. lag B. log C. death D. stationary E. intermediate

D. stationary

What is not a feature inherent in active transport systems? A. they transport nutrients against the natural diffusion gradient B. they are made up of specific membrane proteins C. they transport nutrients in the same direction as the natural diffusion gradient but at a faster rate D. they form energy during transport E. they are an efficient system for transporting carbohydrates, amino acids, organic acids, phosphates, and metal ions

D. they form energy during transport

Each of the following are true of enzymes except A. they can be used over and over. B. they may or may not require cofactors. C. their active site is specific to the substrate. D. they increase the activation energy of a reaction. E. All of the choices are true of enzymes.

D. they increase the activation energy of a reaction.

What form of oxygen is not toxic to microorganisms? A. OH- B. H202 C. O2- D. 1O2 E. O2

E. O2

Osmosis requires that a membrane have what property? A. allow for the expenditure of energy B. have carrier proteins that participate in transport C. be freely soluble to all solute molecules D. exhibit Brownian movement E. be selectively permeable to molecules other than water

E. be selectively permeable to molecules other than water

What nutritional category of microorganisms plays an important part in recycling inorganic nutrients? A. photoautotrophs B. chemoheterotroph C. saprobes D. photoheterotrophs E. chemoautotrophs

E. chemoautotrophs

A ________ is used in industrial microbiology to produce microbial products that are only synthesized during log phase growth. A. Coulter counter B. broth culture C. spectrophotometer D. pour plate E. chemostat

E. chemostat

What defines a viral plaque? A. the sticky substance that accumulates on teeth B. cell cultures infected by a virus C. freshly isolated animal tissue placed in growth medium D. a line of cells that can grow continuously E. clear, well-defined areas in a monolayer of cells

E. clear, well-defined areas in a monolayer of cells

Virus-induced damage to a cell that alters its microscopic appearance is known as what? A. lysis B. lysogeny C. chronic damage D. persistent damage E. cytopathic effects

E. cytopathic effects

Organisms that can grow with or without oxygen present are A. obligate aerobes. B. facultative anaerobes. C. aerotolerant anaerobes. D. obligate anaerobes. E. either facultative anaerobes or aerotolerant anaerobes.

E. either facultative anaerobes or aerotolerant anaerobes.

At temperatures higher than the maximum growth temperature for an organism, A. proteins are permanently denatured. B. membranes become too fluid for proper function. C. hydrogen bonds within molecules are broken. D. hydrogen bonds are broken and proteins are permanently denatured. E. hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.

E. hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.

How is Taq polymerase from Thermus aquaticus able to function when used in the polymerase chain reaction? A. it has heat stable nucleic acids B. it functions under extremely acidic conditions C. it has a cell membrane that resists heat D. it copies DNA fragments E. it is a heat stable enzyme

E. it is a heat stable enzyme

A microbe that grows only at the bottom of a tube of thioglycolate medium is probably a(n) A. obligate aerobe. B. facultative anaerobe. C. aerotolerant anaerobe. D. microaerophile. E. obligate anaerobe.

E. obligate anaerobe.

Nitrogen is a growth-limiting nutrient for many organisms because A. it is necessary for the biosynthesis of amino acids. B. it is required for synthesis of nucleotides. C. it is required for lipid synthesis. D. only a small number of bacteria are able to extract it from the atmosphere. E. only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis.

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

All of the following viruses can be involved in cancer except... A. HTLV I B. HTLV II C. papilloma virus D. Epstein-Barr virus E. rabies virus

E. rabies virus

Adsorption of the bacteriophage occurs when molecules on the tail fibers bind to what component on the host cell? A. capsomers B. nucleocapsid C. nucleus D. cell membrane E. receptors

E. receptors

Molecules that protrude from the viral envelope and which are essential for attachment are known as what? A prophage B extrusions C prions D plaques E spikes

E. spikes

A clinical sample labeled as "sputum" was collected from A. the skin. B. the blood. C. the central nervous system. D. a piece of tissue. E. the lungs.

E. the lungs.

An enveloped virus may acquire its envelope from all but which of the following? A. nuclear envelope B. Golgi apparatus C. endoplasmic reticulum D. cell membrane E. cytoplasmic membrane

b. Golgi apparatus