Microbio chapter 7

How is budding of bacteria to produce daughter cells different from binary fission? A. The chromosome does not need to be replicated. B. The cytoplasmic division is unequal. C. The bud doesn't receive any DNA. D. A septum must form during budding.

The cytoplasmic division is unequal.

Which of the following is most similar between the cell cycle process of Sulfolobus and that of bacteria? A. The segregation of the chromosomes B. The cytokinesis process C. The timing of events during G1, S, and G2

The segregation of the chromosomes

Which of the following strategies enable non-acidophilic bacteria to endure lower pH environments? A. Presence of internal buffers B. Proton pumps that pump H+ out of the cell C. Synthesis of acid shock proteins that protect other cellular proteins D. All of the choices are correct.

all of the choices are correct

Which of the following can be used to isolate pure cultures of bacteria from mixtures? A. Spread plates B. Streak plates C. Pour plates D. All of the choices are correct.

all of these choices are correct

At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the culture enters stationary phase with a population of 65 million cells. At what time is the population half maximal? A. 6:30 p.m. B. 7:20 p.m. C. 8:20 p.m. D. 8:40 p.m.

8:40 pm

Which of the following is considered a cardinal growth temperature? A. The minimum temperature B. The maximum temperature C. The optimum temperature D. All of these are considered cardinal growth temperatures.

All of these are considered cardinal growth temperatures.

At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has population of 65 million cells. The approximate number of generations that has occurred is A. 5. B. 13. C. 21. D. 27.

13

At 4:00 p.m. a closed flask of sterile broth is inoculated with 10,000 cells. The lag phase lasts 1 hour. At 9:00 p.m. the log phase culture has a population of 65 million cells. The mean generation time is approximately A. 10 minutes. B. 20 minutes. C. 30 minutes. D. 40 minutes.

20 minutes

Given a log phase bacterial culture with 1 x 10^6 cells per ml and a generation time of 30 minutes, how long does it take the culture to reach a density of 6.4 x 10^7 cells per ml? A. 1 hour B. 2 hours C. 3 hours D. 4 hours

3 hours

The actin-like protein that seems to be involved in determining cell shape is A. MreB. B. ActA. C. SpnC. D. FtsZ.

MreB

Which of the following proteins is central to starvation survival strategies in many bacteria? A. Fts Z B. RpoS C. Superoxide dismutase D. ATPase

RpoS

Organisms that require increased pressure for optimum growth are called A. barotolerant. B. osmotolerant. C. barophilic. D. osmophilic.

barophilic

Organisms that are not drastically affected by increased pressure are called A. barotolerant. B. osmotolerant. C. barophilic. D. osmophilic.

barotolerant

Organisms that grow near deep-sea volcanic vents are likely to be A. alkylophilic. B. acidophilic. C. barophilic or barotolerant. D. picrophilic.

basophilic or barotolerant

A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a __________ culture. A. continuous B. batch C. fed-batch D. semicontinuous

batch

Most bacterial and archaeal cells divide by A. mitosis. B. meiosis. C. binary fission. D. All of the choices are correct.

binary fission

An open system in which the growth rate is maintained by adding a nutrient (present in limiting quantities) at the same rate that medium containing microorganisms is removed is called a A. manostat. B. chemostat. C. turbidostat. D. culturostat.

chemostat

1. Media containing some ingredients of unknown chemical composition are called __________ media. A. undefined B. complex C. defined D. synthetic

complex

You would like to culture a bacterium that is growing in the lung of a human patient with pneumonia. Which media would be of most use in culturing this organism? A. Transport media B. Mannitol salt agar C. MacConkey's agar D. Complex medium supplemented with whole blood E. None of the choices are correct.

complex media supplemented with whole blood

A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes is called __________ culture system. A. continuous B. batch C. fed-batch D. semicontinuous

continuous

Media in which all components and their concentration are known are called __________ media. A. transport B. defined C. selective D. enrichment

defined

A growth medium that distinguishes among different groups of bacteria on the basis of their biological characteristics is called a __________ medium. A. selective B. differential C. enrichment D. transport

differential

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes); nonhalophiles will not grow. Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter and a halophilic mannitol nonfermenter. In this case, the medium is acting as (a) __________ medium(s). A. selective B. differential C. selective and differential D. enrichment

differential

n a continuous culture system, the rate at which media is added and removed is called the __________ rate. A. dilution B. chemostatic C. pass-through D. flow-through

dilution

The total number of viable microorganisms remains constant in stationary phase because A. there is a balance between cell division and cell death. B. there is a cessation of cell division even though the cells may remain metabolically active. C. either there is a balance between cell division and cell death or there is a cessation of cell division even though the cells may remain metabolically active. D. None of the choices are correct.

either there is a balance between cell division and cell death or there is a cessation of cell division even though the cells may remain metabolically active.

Microorganisms are most nearly uniform in terms of chemical and physiological properties during __________ phase. A. lag B. exponential C. stationary D. decline

exponential

All fastidious microorganisms require which of the following for growth? A. Oxygen B. Temperatures near normal for the human body C. Extra nutrients (such as whole blood) D. Iron

extra nutrients (such as whole blood)

Organisms that do not require oxygen for growth but grow better in its presence are called A. facultative anaerobes. B. microaerophiles. C. aerotolerant. D. anoxygenic.

facultative anaerobes.

Membranes of thermophilic bacteria are stabilized by phospholipids with A. fatty acids that tend to be more saturated. B. fatty acids that have lower molecular weights. C. fatty acids that have more double bonds. D. All of the choices are correct.

fatty acids that tend to be more saturated.

Bacteria reproductive strategies include all of the following EXCEPT A. binary fission. B. budding. C. multiple fission. D. formation of mutinucleoid filaments that break apart into uninucleate spores. E. fusion of two bacterial cells that then split into four uninucleate cells.

fusion of two bacterial cells that then split into four uninucleate cells.

Agar is an excellent solidifying agent for microbiological media because A. it is not degraded by most microorganisms. B. solid agar remains solid until the temperature is raised to 90C, and liquid agar remains liquid if the temperature is lowered to 45C. C. it is not degraded by most microorganisms and solid agar remains solid until the temperature is raised to 90C, and liquid agar remains liquid if the temperature is lowered to 45C are correct. D. agar provides an excellent source of nutrition for a variety of different microorganisms.

it is not degraded by most microorganisms and solid agar remains solid until the temperature is raised to 90C, and liquid agar remains liquid if the temperature is lowered to 45C are correct.

Which of these methods can be used to determine the number of viable microorganisms in a sample? A. Light scattering in a spectrophotometer B. Measuring total cell mass C. Measuring colony forming units per ml D. Counting a known volume of cells in a hemocytometer

measuring colony forming units per ml

A microbiologist is testing the drinking water for a municipality. What would be the best method for testing the purified water? A. Viable plate count B. Measurement of microbial mass C. Direct microscopic count D. Membrane filtration

membrane filtration

Organisms that are damaged by the normal atmospheric levels of oxygen (20%) but require oxygen at levels of 2-10% for growth are called A. facultative anaerobes. B. microaerophiles. C. aerotolerant. D. anoxygenic.

microaerophiles

Most microorganisms maintain their internal pH A. near neutral (pH 7). B. near their optimum growth pH. C. slightly acidic (pH 4-6). D. slightly alkaline (pH 8-10).

near neutral (pH 7)

Which of the following methods could be used to detect the presence of viable but nonculturable cells of a pathogen in a water or food specimen? A. Culture on enriched agar B. Use of enrichment techniques C. Polymerase chain reaction D. Culture on selective agar

polymerase chain reaction

Organisms that grow well at 0C and have optimum growth temperatures of 15C or lower are called A. psychrotrophs. B. psychrophiles. C. frigiphiles. D. mesophiles.

psychrophiles

Organisms that grow at 0C and have a maximum growth temperature of 35C are called A. psychrotrophs. B. psychrophiles. C. frigiphiles D. mesophiles.

psychrotrophs

The __________ is a group of proteins needed for DNA synthesis that assembles at the origin of replication. A. septum B. replisome C. prospore D. None of the choices are correct.

replisome

A growth medium that favors the growth of some microorganisms but inhibits the growth of other microorganisms is a __________ medium. A. selective B. differential C. selective and differential D. neither selective nor differential

selective

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters release acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol nonfermenter and a nonhalophilic mannitol nonfermenter. Here the medium acts as a __________ medium. A. selective B. differential C. selective and differential D. enrichment

selective

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters release acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter, a nonhalophilic mannitol fermenter, and a halophilic mannitol nonfermenter. Thus, the medium is acting as a __________ medium. A. selective B. differential C. selective and differential D. neither selective nor differential

selective and differential

The process of forming a cross wall between two daughter cells is known as _______________. A. replication B. septation C. sporulation D. mitosis

septation

Which type of lifestyle is demonstrated by bacteria in biofilms? A. Planktonic B. Photoautotrophic C. Parasitic D. Sessile

sessile

All of the following are characteristics of spread plates EXCEPT A. colonies that grow on the surface of the agar. B. specimens that are typically diluted prior to inoculation of a spread plate. C. spread plates that readily grow anaerobic bacteria. D. spread plates that are typically inoculated with a bent glass rod.

spread plates that readily grow anaerobic bacteria.

The limitation on microbial growth rate at high nutrient levels is/are A. the rate of protein synthesis. B. the rate of DNA replication. C. the saturation of the transport proteins for nutrient uptake. D. All of the choices are correct.

the saturation of the transport proteins for nutrient uptake.

Organisms that grow near deep-sea volcanic vents are likely to be A. psychrophilic. B. psychrotrophic. C. mesophilic. D. thermophilic.

thermophilic

An open system in which the growth rate is maintained by the removal and addition of media at such a rate as to maintain a constant cell density is called a A. manostat. B. chemostat. C. turbidostat. D. culturostat.

turbidostat

The membranes of psychrophilic bacteria have relatively high levels of __________ fatty acids, which allow them to remain semifluid at cold temperatures. A. saturated B. unsaturated C. sterol D. aromatic

unsaturated

One hypothesis about the decline in cell numbers during death phase is that the cells aren't all dying but instead remain alive but unable to grow when cultured, at least temporarily. These are known as A. viable but nonculturable cells. B. ghost cells. C. death phase cells. D. programmed death cells.

viable but nonculturable cells

A microbiologist is studying the growth of a particular strain of bacteria to determine when it will transition from exponential growth to stationary phase and from stationary phase to death phase. Which of the following methods of measuring microbial growth would be best for this purpose? A. Direct microscopic count B. Determining dry weight of microbes C. Turbidimetric measurements using a spectrophotometer D. Viable plate count

viable plate count

During cytokinesis, a critical step in septation is the assembly of the A. replisome. B. spindle body. C. Z ring. D. cytoskeletal spiral.

z ring

Organisms that grow in the mud under relatively nonturbulent bodies of water are likely to be A. obligate aerobes. B. thermophilic. C. barophilic. D. anaerobes.

anaerobes

Which of the following do airborne microorganisms and microorganisms on light-exposed surfaces use to protect themselves from photooxidation? A. Catalase enzymes B. Peroxidase enzymes C. Carotenoid pigments D. Superoxide dismutase

Carotenoid pigments

A microbiologist is trying to isolate a pathogen expected to be present in very small numbers from a stool specimen in which there are abundant normal microbiota. Which strategy would most likely accomplish this purpose? A. Culture on enriched media B. Enrichment culture followed by culture on selective agar C. Culture on differential media D. Culture in an anaerobe jar

Enrichment culture followed by culture on selective agar

Unlike Sulfolobus, some Archaea use ___________ protein(s) to accomplish cytokinesis. A. Tubulin B. Seg A and Seg B C. CdvA, CdvB, and CdvC D. FtsZ

FtsZ

Which of the following is the correct order for binary fission? A. A septum forms at midcell, the cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell. B. The cell elongates, a septum forms at midcell, the cell replicates its chromosome, and separates the chromosome into the two parts of the cell. C. The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell. D. None of the choices are correct.

The cell elongates, replicates its chromosome, and separates the chromosome into the two parts of the cell, and a septum forms at midcell.

How is the cell cycle of Sulfolobus spp. similar to that of eukaryotes? A. Sulfolobus has microtubules composed of a tubulin homolog that separate the chromosomes. B. Sulfolobus demonstrates prophase, metaphase, anaphase, and telophase. C. A centrosome is apparent in Sulfolobus during G2. D. The cytokinesis process in Sulfolobus is similar to the process in eukaryotes.

The cytokinesis process in Sulfolobus is similar to the process in eukaryotes.

What is the result of successful communication between rhizobia and their plant hosts? A. Rhizobia consume the plant tissue as an energy and carbon source, causing disease in the plant. B. The plant consumes rhizobiaas an energy source and carbon, destroying the invading bacteria. C. The rhizobia invade the plant root and begin to fix nitrogen with the assistance of the plant. D. The plant supplies organic forms of nitrogen to the rhizobia.

The rhizobia invade the plant root and begin to fix nitrogen with the assistance of the plant.

Organisms that ignore oxygen and grow equally well in its presence or absence are called A. facultative anaerobes. B. microaerophiles. C. aerotolerant. D. anoxygenic.

aerotolerant

For surface cultivation of microorganisms, a sulfated polymer called agar can be extracted from __________ and added to liquid media in order to cause it to solidify. A. bacteria B. animal fat C. algae D. fungi

algae

Cells may enter stationary phase because of A. the depletion of an essential nutrient. B. a lack of available oxygen. C. the accumulation of toxic waste products. D. All of the choices are correct.

all of the choices are correct

The length of the lag phase of growth can vary depending on A. the condition of the microorganisms. B. the nature of the growth medium. C. the temperature. D. All of the choices are correct.

all of the choices are correct

Which of the following are a reason(s) for the decline in cell numbers during the death phase? A. Depletion of nutrients B. Accumulation of toxic waste materials C. Depletion of O2 D. All of the choices are correct.

all of the choices are correct

Which of the following may form one colony? A. A single bacterial cell B. A short chain of bacteria C. A small clump of bacteria D. All of the choices are correct.

all of the choices are correct

Which of the following is a reason for the occurrence of a lag phase in a bacterial growth curve? A. The cells may be old and depleted of ATP, essential cofactors, and ribosomes that must be synthesized before growth can begin. B. The medium may be different from the previous growth medium so that the cells must synthesize new enzymes to use different nutrients. C. The organisms may have been injured and require time to recover. D. All of these are potential reasons.

all of these are potential reasons

Quorum sensing A. is a phenomenon in which bacteria monitor their own population density. B. depends on the sensing of signal protein molecules. C. plays an important role in formation of biofilms by Pseudomonas aeruginosa. D. All of the choices are correct.

all these choices are correct

Which of the following can be used to estimate the number of microorganisms in a culture? A. Direct counts of microbial cells B. Counts of viable cells using colony growth procedures C. Measurements of microbial biomass D. All of the choices are correct.

all these choices are correct