Question 1

Turbidity measurements are commonly utilized for monitoring

Accepted Answer

A)  planktonic cultures. 
B)  biofilms. 
C)  conies. 
D)  sessile cultures. 
A)  planktonic cultures. 
B)  biofilms. 
C)  conies. 
D)  sessile cultures. A

Question 2

A halotolerant facultative anaerobe would grow BEST in which of the following environments?

Accepted Answer

A)  oxygen depleted saline 
B)  oxygenated saline 
C)  oxygen depleted non-saline 
D)  oxygenated non-saline 
A)  oxygen depleted saline 
B)  oxygenated saline 
C)  oxygen depleted non-saline 
D)  oxygenated non-saline D

Question 3

Discuss the pros and cons of using radiation to sterilize items such as foods, drugs, and surgical supplies.

Accepted Answer

UV radiation sterilizes only the surfaces of objects which can be problematic for foods that are not fully cooked on the inside. Ionizing radiation can penetrate so they are ideal for foods such as grain cereals and ground beef. The high costs associated with the specialized equipment make it feasible only for large industrial applications. Due to the high energy of some of these radiation procedures, there are many concerns of potential radioactive contamination, production of carcinogenic or toxic products, and nutritional value alteration.

Question 4

Which of these statements is/are TRUE?

Accepted Answer

A)  In general, species that can grow at higher temperatures are prokaryotic. 
B)  The most thermophilic prokaryotes are species of Archaea. 
C)  Chemoorganotrophic organisms are able to grow at higher temperatures than phototrophic organisms. 
D)  All of the statements are true. 
A)  In general, species that can grow at higher temperatures are prokaryotic. 
B)  The most thermophilic prokaryotes are species of Archaea. 
C)  Chemoorganotrophic organisms are able to grow at higher temperatures than phototrophic organisms. 
D)  All of the statements are true.

Question 5

Relative to enzymes in mesophilic microorganisms, which of the following is NOT characteristic of enzymes in psychrophiles?

Accepted Answer

A)  decreased alpha helix content 
B)  decreased beta sheet content 
C)  fewer hydrogen bonds 
D)  fewer ionic bonds 
A)  decreased alpha helix content 
B)  decreased beta sheet content 
C)  fewer hydrogen bonds 
D)  fewer ionic bonds

Question 6

Irreversible cell damage is more likely to occur at low rather than high temperatures.

Accepted Answer

A) True 
 B)False

Question 7

The cell membranes of thermophiles and hyperthermophilic bacteria typically have

Accepted Answer

A)  more saturated fatty acids. 
B)  more long chain fatty acids. 
C)  fewer unsaturated fatty acids. 
D)  All of these answer choices are true of thermophiles and hyperthermophilic bacteria. 
A)  more saturated fatty acids. 
B)  more long chain fatty acids. 
C)  fewer unsaturated fatty acids. 
D)  All of these answer choices are true of thermophiles and hyperthermophilic bacteria.

Question 8

Why are microbial doubling times in nature typically longer than those obtained in the laboratory?

Accepted Answer

The general theme should be on how lab c

Question 9

Cell density in a chemostat is controlled by

Accepted Answer

A)  the concentration of the limiting nutrient. 
B)  the dilution factor. 
C)  the size of the initial inoculum. 
D)  the concentration of the limiting nutrient, the dilution factor, and the size of the initial inoculum. 
A)  the concentration of the limiting nutrient. 
B)  the dilution factor. 
C)  the size of the initial inoculum. 
D)  the concentration of the limiting nutrient, the dilution factor, and the size of the initial inoculum.

Question 10

Planktonic cells remain in suspension while sessile cells adhere to a surface.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following forms of oxygen is/are generally toxic to living organisms?

Accepted Answer

A)  superoxide anion 
B)  hydrogen peroxide 
C)  hydroxyl radical 
D)  Superoxide, hydrogen peroxide, and hydroxyl radicals are all toxic. 
A)  superoxide anion 
B)  hydrogen peroxide 
C)  hydroxyl radical 
D)  Superoxide, hydrogen peroxide, and hydroxyl radicals are all toxic.

Question 12

Which term is most relevant in describing the efficacy of an antimicrobial for use in a clinical setting?

Accepted Answer

A)  effective dose 
B)  sterilization coefficient 
C)  lethal dosage 
D)  minimum inhibitory concentration (MI
C)  
A)  effective dose 
B)  sterilization coefficient 
C)  lethal dosage 
D)  minimum inhibitory concentration (MI
C)

Question 13

A bacterial cell in nutrient broth with a generation time of 15 minutes will produce 16 cells in 2 hours.

Accepted Answer

A) True 
 B)False

Question 14

Describe the autoclave, and explain the roles of time, temperature, and pressure in the functioning of the autoclave.

Accepted Answer

High pressure is used in an autoclave so

Question 15

Taq polymerase was isolated from a thermophile and is used in the polymerase chain reaction (PCR) technique because it does not become inactivated at high temperatures.

Accepted Answer

A) True 
 B)False

Question 16

When attempting to determine viable cell counts of a heat-sensitive bacterial isolate, which cell counting method should be avoided?

Accepted Answer

A)  spread-plate method 
B)  pour-plate method 
C)  live staining and direct counting with a microscope 
D)  both spread- and pour-plate methods 
A)  spread-plate method 
B)  pour-plate method 
C)  live staining and direct counting with a microscope 
D)  both spread- and pour-plate methods

Question 17

A selective medium is used to suppress the growth of certain bacteria in order to facilitate the growth of other bacteria.

Accepted Answer

A) True 
 B)False

Question 18

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is

Accepted Answer

A)  disinfection. 
B)  sterilization. 
C)  antisepsis. 
D)  sanitization. 
A)  disinfection. 
B)  sterilization. 
C)  antisepsis. 
D)  sanitization.

Question 19

Knowing the concentration of microorganisms in a sample is often an important consideration for environmental, industrial, and medical microbiologists, yet a microscope is sometimes not used to accomplish this task. Explain five major limitations to using a light microscope to directly count microorganisms.

Accepted Answer

All of the following eight are potential

Question 20

Which of the following methods used to enumerate cells often requires specialized staining to observe non-pigmented bacteria?

Accepted Answer

A)  spectrophotometry/turbidity 
B)  spread-plating 
C)  microscopy 
D)  spread-plating, turbidity, and microscopy 
A)  spectrophotometry/turbidity 
B)  spread-plating 
C)  microscopy 
D)  spread-plating, turbidity, and microscopy

Exam 5: Microbial Growth and Its Control

Turbidity measurements are commonly utilized for monitoring

A halotolerant facultative anaerobe would grow BEST in which of the following environments?

Discuss the pros and cons of using radiation to sterilize items such as foods, drugs, and surgical supplies.

Which of these statements is/are TRUE?

Relative to enzymes in mesophilic microorganisms, which of the following is NOT characteristic of enzymes in psychrophiles?

Irreversible cell damage is more likely to occur at low rather than high temperatures.

The cell membranes of thermophiles and hyperthermophilic bacteria typically have

Why are microbial doubling times in nature typically longer than those obtained in the laboratory?

Cell density in a chemostat is controlled by

Planktonic cells remain in suspension while sessile cells adhere to a surface.

Which of the following forms of oxygen is/are generally toxic to living organisms?

Which term is most relevant in describing the efficacy of an antimicrobial for use in a clinical setting?

A bacterial cell in nutrient broth with a generation time of 15 minutes will produce 16 cells in 2 hours.

Describe the autoclave, and explain the roles of time, temperature, and pressure in the functioning of the autoclave.

Taq polymerase was isolated from a thermophile and is used in the polymerase chain reaction (PCR) technique because it does not become inactivated at high temperatures.

When attempting to determine viable cell counts of a heat-sensitive bacterial isolate, which cell counting method should be avoided?

A selective medium is used to suppress the growth of certain bacteria in order to facilitate the growth of other bacteria.

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is

Which of the following methods used to enumerate cells often requires specialized staining to observe non-pigmented bacteria?

The Microbial World

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Information Flow and Protein Processing

Microbial Regulatory Systems

Molecular Biology of Microbial Growth

Viruses and Their Replication

Microbial Systems Biology

Viral Genomics, Diversity, and Ecology

Genetics of Bacteria and Archaea

Biotechnology and Synthetic Biology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Microorganisms

Diversity of Bacteria

Diversity of Archaea

Diversity of Microbial Eukarya

Taking the Measure of Microbial Systems

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Symbioses with Humans

Microbial Infection and Pathogenesis

Innate Immunity: Broadly Specific Host Defenses

Adaptive Immunity: Highly Specific Host Defenses

Clinical Microbiology and Immunology

Epidemiology

Person-to-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Waterborne and Foodborne Bacterial and Viral Diseases

Eukaryotic Pathogens: Fungi, Protozoans, and Helminths

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