Question 1

The rate of exponential growth varies greatly according to bacterial species and bioavailable nutrients.

Accepted Answer

A) True 
 B)False

Question 2

Which method would be LEAST effective at sterilizing a glass hockey stick to use in the spread-plate method?

Accepted Answer

A)  autoclaving 
B)  gamma radiation 
C)  ethanol soaking 
D)  ultrahigh-temperature pasteurization 
A)  autoclaving 
B)  gamma radiation 
C)  ethanol soaking 
D)  ultrahigh-temperature pasteurization

Question 3

A chemical that denatures proteins is most likely to be classified as a(n) ________ agent.

Accepted Answer

A)  antiseptic 
B)  bacteriostatic 
C)  bacteriocidal 
D)  detergent 
A)  antiseptic 
B)  bacteriostatic 
C)  bacteriocidal 
D)  detergent

Question 4

Organisms able to live in environments with high sugar concentrations are

Accepted Answer

A)  halotolerant. 
B)  osmophiles. 
C)  xerophiles. 
D)  anaerobic fermenting bacteria. 
A)  halotolerant. 
B)  osmophiles. 
C)  xerophiles. 
D)  anaerobic fermenting bacteria.

Question 5

Sterility of a laminar flow hood is accomplished by filter-sterilized air passed through the hood quickly enough that non-sterile air does not flow into the work area.

Accepted Answer

A) True 
 B)False

Question 6

Cultures of a bacterial species were incubated on the shelf of a refrigerator (5°C), on a lab benchtop (25°C), on the shelf of a 37°C incubator, and on the shelf of a 50°C incubator. After incubation, there was no growth at 37°C or 50°C, slight growth on the benchtop, and abundant growth at refrigeration. What term could be used for this species?

Accepted Answer

A)  halophile 
B)  mesophile 
C)  anaerobe 
D)  psychrophile 
A)  halophile 
B)  mesophile 
C)  anaerobe 
D)  psychrophile

Question 7

The time between inoculation and the beginning of growth is usually called the

Accepted Answer

A)  lag phase. 
B)  log phase. 
C)  dormant phase. 
D)  death phase. 
A)  lag phase. 
B)  log phase. 
C)  dormant phase. 
D)  death phase.

Question 8

By controlling the concentration of nutrients continuously added to a chemostat, cells can constantly be maintained at the

Accepted Answer

A)  exponential growth phase. 
B)  stationary growth phase. 
C)  lag growth phase. 
D)  death growth phase. 
A)  exponential growth phase. 
B)  stationary growth phase. 
C)  lag growth phase. 
D)  death growth phase.

Question 9

A medium containing known substances in precise amounts is known as a ________ media.

Accepted Answer

A)  selective 
B)  complex 
C)  natural 
D)  defined 
A)  selective 
B)  complex 
C)  natural 
D)  defined

Question 10

Serial dilutions are generally made

Accepted Answer

A)  when the appropriate viable count is unknown. 
B)  based on powers of 10, although other serial dilution factors are possible. 
C)  to reach a suitable dilution while minimizing error. 
D)  All of these answer choices apply. 
A)  when the appropriate viable count is unknown. 
B)  based on powers of 10, although other serial dilution factors are possible. 
C)  to reach a suitable dilution while minimizing error. 
D)  All of these answer choices apply.

Question 11

Some microbes can grow in boiling water.

Accepted Answer

A) True 
 B)False

Question 12

Many fungi and bacteria grow best at pH 5 or below.

Accepted Answer

A) True 
 B)False

Question 13

A microbe growing in a refrigerator is likely

Accepted Answer

A)  psychrophilic. 
B)  mesophilic. 
C)  psychrotolerant or psychrophilic. 
D)  hyperthermophilic. 
A)  psychrophilic. 
B)  mesophilic. 
C)  psychrotolerant or psychrophilic. 
D)  hyperthermophilic.

Question 14

What temperature is most commonly used in autoclaves to sterilize growth media and other devices prior to experimentation?

Accepted Answer

A)  95°C 
B)  101°C 
C)  121°C 
D)  140°C 
A)  95°C 
B)  101°C 
C)  121°C 
D)  140°C

Question 15

Would you expect a xerophilic organism to be halotolerant? Why or why not?

Accepted Answer

Yes, xerophiles are typically halotolera

Question 16

Optical density and viable cell concentration are LEAST proportional to each other during the

Accepted Answer

A)  lag phase. 
B)  exponential growth phase. 
C)  stationary phase. 
D)  death phase. 
A)  lag phase. 
B)  exponential growth phase. 
C)  stationary phase. 
D)  death phase.

Question 17

Bacteria that are able to grow in humans and cause disease would be classified as

Accepted Answer

A)  psychrophiles. 
B)  mesophiles. 
C)  thermophiles. 
D)  hyperthermophiles. 
A)  psychrophiles. 
B)  mesophiles. 
C)  thermophiles. 
D)  hyperthermophiles.

Question 18

The death phase applies to individual cells rather than populations.

Accepted Answer

A) True 
 B)False

Question 19

Bacterial growth refers to

Accepted Answer

A)  an increase in the number of cells. 
B)  the occurrence of binary fission. 
C)  the time required for one cell to divide into two. 
D)  the occurrence of mitosis. 
A)  an increase in the number of cells. 
B)  the occurrence of binary fission. 
C)  the time required for one cell to divide into two. 
D)  the occurrence of mitosis.

Question 20

Compare and contrast the spread plate method and the pour plate method of doing plate counts. Also describe which group of organisms would not be quantifiable in the pour plate method but would still be observed in the spread plate method.

Accepted Answer

Answers will vary, but one benefit to th

Exam 5: Microbial Growth and Its Control

The rate of exponential growth varies greatly according to bacterial species and bioavailable nutrients.

Which method would be LEAST effective at sterilizing a glass hockey stick to use in the spread-plate method?

A chemical that denatures proteins is most likely to be classified as a(n) ________ agent.

Organisms able to live in environments with high sugar concentrations are

Sterility of a laminar flow hood is accomplished by filter-sterilized air passed through the hood quickly enough that non-sterile air does not flow into the work area.

The time between inoculation and the beginning of growth is usually called the

By controlling the concentration of nutrients continuously added to a chemostat, cells can constantly be maintained at the

A medium containing known substances in precise amounts is known as a ________ media.

Serial dilutions are generally made

Some microbes can grow in boiling water.

Many fungi and bacteria grow best at pH 5 or below.

A microbe growing in a refrigerator is likely

What temperature is most commonly used in autoclaves to sterilize growth media and other devices prior to experimentation?

Would you expect a xerophilic organism to be halotolerant? Why or why not?

Optical density and viable cell concentration are LEAST proportional to each other during the

Bacteria that are able to grow in humans and cause disease would be classified as

The death phase applies to individual cells rather than populations.

Bacterial growth refers to

Compare and contrast the spread plate method and the pour plate method of doing plate counts. Also describe which group of organisms would not be quantifiable in the pour plate method but would still be observed in the spread plate method.

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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