Test Bank Of Microbiology 1st Edition By Wessner

Test Bank Of Microbiology 1st Edition By Wessner

Package Title: Test Bank
Course Title: Wessner1e
Chapter Number: 6

Question Type: Multiple Choice

1) Which one of the following elements is considered a microelement, usually required in minute amounts in microbiological media?

a) phosphate
b) potassium
c) iron
d) manganese
e) magnesium

Answer: d

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

2) What is the function of siderophores?

a) Transporting waste products out of the cell.
b) Binding iron for transport into the cell.
c) Binding glucose for transport into the cell.
d) Transporting proteins out of the cell.
e) Moving potassium into the cell for osmotic regulation.

Answer: b

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

3) An autotroph is defined as an organism that uses _____ as a source of _____.

a) sunlight; energy
b) organic compounds; carbon
c) organic compounds; energy
d) inorganic compounds; energy
e) carbon dioxide; carbon

Answer: e

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

4) A heterotroph is defined as an organism that uses _____ as a source of _____.

a) sunlight; energy
b) organic compounds; carbon
c) organic compounds; energy
d) inorganic compounds; energy
e) carbon dioxide; carbon

Answer: b

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

5) What is the most readily useable form of nitrogen by microorganisms?

a) dinitrogen
b) ammonium ion
c) nitrate
d) nitrite
e) nitric oxide

Answer: b

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

6) What is nitrogen fixation?

a) The oxidation of nitrate to ammonia for assimilation.
b) The oxidation of ammonia to nitrate for assimilation.
c) The reduction of dinitrogen to ammonia for assimilation.
d) The reduction of nitrate to dinitrogen for assimilation.
e) The release of an amino group from an amino acid for assimilation.

Answer: c

Difficulty: Medium
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

7) What is the most abundant form of nitrogen in the biosphere?

a) ammonia
b) nitrate
c) nitrite
d) dinitrogen
e) nitrous oxide

Answer: d

Difficulty: Medium
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

8) A phototroph is defined as an organism that uses _____ as a source of _____.

a) carbon dioxide; carbon
b) organic compounds; carbon
c) inorganic compounds; energy
d) sunlight; energy
e) organic compounds; energy

Answer: d

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

9) A lithotroph is defined as an organism that uses _____ as a source of _____.

a) inorganic compounds; energy and electrons
b) organic compounds; energy and electronss.
c) inorganic compounds; carbon
d) sunlight; energy
e) carbon dioxide; energy

Answer: a

Difficulty: Medium
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

10) What is the most common solidifying agent used in microbiological media?

a) gelatin
b) agar
c) alginate
d) silica
e) polyacrylamide

Answer: b

Difficulty: Easy
Learning Objective: LO 6.1 Define the various metabolisms common to microbes.
Section Reference: Section 6.1 Nutritional Requirements of Microorganisms

11) Which one of the following is NOT a physical factor that affects the growth rate of cells?

a) nutrient concentration
b) temperature
c) pressure
d) light intensity
e) radiation

Answer: a

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

12) What term applies to a microbe that can synthesize all of its cellular constituents from a simple carbon source and inorganic salts?

a) autotroph
b) heterotroph
c) auxotroph
d) prototroph
e) a chemotroph

Answer: d

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

13) Term that applies to a bacterium that has an absolute requirement of oxygen for growth..

a) aerobe
b) anaerobe
c) aerotolerant anaerobe
d) facultative anaerobe
e) facultative aerobe

Answer: a

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

14) Term for a bacterium that does not use oxygen for growth, but will grow in the presence of oxygen.

a) aerobe
b) anaerobe
c) aerotolerant anaerobe
d) facultative anaerobe
e) facultative aerobe

Answer: c

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

15) The enzyme catalase is used to detoxify which harmful oxygen species?

a) hydroxyl radical
b) superoxide
c) hydrogen peroxide
d) ozone
e) singlet oxygen

Answer: c

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

16) What is the term for microbes that grow optimally at a pH below 5.5?

a) alkalophiles
b) psychrophiles
c) halophiles
d) acidophiles
e) barophiles

Answer: d

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

17) Term for microbes that grow optimally at very high salt concentrations.

a) osmolphiles
b) barophiles
c) halophiles
d) psychrophiles
e) thermophiles

Answer: c

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

18) Term for microbes that grow optimally at a pH above 8.5.

a) acidophiles
b) alkalophiles
c) barophiles
d) psychrophiles
e) halophiles

Answer: b

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

19) Term applied to microbes that grow optimally at temperatures below 15°C.

a) psychrophiles
b) barophiles
c) alkalophiles
d) mesophiles
e) halophiles

Answer: a

Difficulty: Easy
Learning Objective: LO 6.2 Describe the various environmental conditions that affect microbial growth and how bacteria can be categorized by their growth preferences.
Section Reference: Section 6.2 Factors affecting microbial growth

20) Enrichment media that contains starch as the sole carbon source is encouraging the growth of microbes that produce _____ .

a) glucose
b) the enzyme amylase
c) the enzyme cellulase
d) all twenty amino acids
e) all required vitamins

Answer: b

Difficulty: Medium
Learning Objective: LO 6.3 Explain how bacteria may be cultured in the laboratory and the methods used to study unculturable microbes.
Section Reference: Section 6.3 Growing microorganisms in the laboratory

21) In the environment, one microorganism often provides a nutrient for another microbe that is unable to synthesize the nutrient by itself. What is this type of relationship called?

a) auxotrophy
b) prototrophy
c) syntrophy
d) oligotrophy
e) eutrophy

Answer: c

Difficulty: Easy
Learning Objective: LO 6.3 Explain how bacteria may be cultured in the laboratory and the methods used to study unculturable microbes.
Section Reference: Section 6.3 Growing microorganisms in the laboratory

22) Which of these methods can be used to obtain a viable cell count?

a) counting chamber direct count
b) turbidity measurement
c) plate counts of serial dilutions
d) loop dilution
e) optical density

Answer: c

Difficulty: Easy
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

23) What would you use to measure the optical density of a bacterial culture?

a) a Petroff-Hauser counting chamber
b) a flow cytometer
c) the plate count method
d) a spectrophotometer
e) a microscope

Answer: d

Difficulty: Easy
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

24) The plate count method was used to estimate the number of bacteria in a culture over time. Serial dilutions were made of culture samples at various time points. A 0.1 ml portion of the 10-6 dilution was spread over the surface of a nutrient agar plate for each time point. The plates were incubated for 24 hrs and the colony forming units (CFU) were counted on each plate. A total of 45 colonies were counted on the plate for the 30 minute time point. What was the cell population for this time point?

a) 45 X 104 CFU/ml
b) 45 X 105 CFU/ml
c) 45 X 106 CFU/ml
d) 45 X 107 CFU/ml
e) 45 X 108 CFU/ml

Answer: d

Difficulty: Medium
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

25) In reference to microbial growth, what conditions prompt the “stringent response”?

a) A shift from a warm to a cold environment.
b) A shift from a nutrient rich to a nutrient poor environment.
c) A shift from an oxygen rich to an oxygen poor environment.
d) A shift from a state of resistance to susceptibility to a bacteriophage.
e) A shift from a light to a dark environment.

Answer: b

Difficulty: Medium
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

26) Fresh media is inoculated with an actively growing Escherichia coli culture. You measure the optical density (OD) at the time of inoculation and record avalue of of 0.05) Two hours later you take another reading and record a optical density of 0.2) What is the generation time for your culture?

a) 30 minutes
b) 40 minutes
c) 50 minutes
d) 60 minutes
e) Cannot determine from the information given.

Answer: d

Difficulty: Medium
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

27) If a cell culture contains 400 cells/ml at time = 0 and it has a generation time of 30 minutes, how many cells (cells/ml) will be present after 2 hours of incubation?

a) 1200 cells/ml
b) 1600 cells/ml
c) 2400 cells/ml
d) 3200 cells/ml
e) 6400 cells/ml

Answer: e

Difficulty: Medium
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth

28) What is the mean growth rate for a culture that has a generation time of 1 hour?

a) 1 hr.
b) 2 hr.
c) 1 hr-1.
d) 2 hr-1.
e) Cannot determine from the information given.

Answer: c

Difficulty: Easy
Learning Objective: LO 6.4 Describe the methods used to determine the density and expansion of bacterial cultures.
Section Reference: Section 6.4 Measuring microbial population growth