Question 1

Which of the following is true of microbes and their membranes?

Accepted Answer

A)  They are relatively permeable to protons. 
B)  Protons can leak through directly when the difference in intracellular and extracellular pH is very high. 
C)  Membrane-permeant organic acids can prevent the leakage of protons. 
D)  They are able to change the pH optima of their enzymes. 
E)  Acidophiles use Na+/H+ antiporters to remove internal protons. 
A)  They are relatively permeable to protons. 
B)  Protons can leak through directly when the difference in intracellular and extracellular pH is very high. 
C)  Membrane-permeant organic acids can prevent the leakage of protons. 
D)  They are able to change the pH optima of their enzymes. 
E)  Acidophiles use Na+/H+ antiporters to remove internal protons.

Question 2

The use of oxygen as the terminal electron acceptor is called

Accepted Answer

A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  fermentation. 
D)  oxygenic photosynthesis. 
E)  carbon dioxide fixation. 
A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  fermentation. 
D)  oxygenic photosynthesis. 
E)  carbon dioxide fixation.

Question 3

How are some organisms able to survive temporary exposures to elevated temperatures?

Accepted Answer

Some organisms exhibit heat-sh

Question 4

The fastest growth rate for a species occurs at temperatures where a cell's ________ work most efficiently.

Accepted Answer

A)  lipids 
B)  membranes 
C)  nucleic acids 
D)  proteins 
E)  polysaccharides 
A)  lipids 
B)  membranes 
C)  nucleic acids 
D)  proteins 
E)  polysaccharides

Question 5

Which of the following grows in the indicated pH range shown in the figure below?

Accepted Answer

A)  psychrophiles 
B)  mesophiles 
C)  piezophiles 
D)  alkaliphiles 
E)  acidophiles 
A)  psychrophiles 
B)  mesophiles 
C)  piezophiles 
D)  alkaliphiles 
E)  acidophiles

Question 6

Psychrophiles favor the cold, since their membranes are more fluid at low temperature as a result of the high proportion of ________ present.

Accepted Answer

A)  saturated fatty acids 
B)  unsaturated fatty acids 
C)  lipopolysaccharides 
D)  transport proteins 
E)  water 
A)  saturated fatty acids 
B)  unsaturated fatty acids 
C)  lipopolysaccharides 
D)  transport proteins 
E)  water

Question 7

Cyanobacterial blooms such as those shown in the figure below are typically due to human-caused

Accepted Answer

A)  antibiotic resistance. 
B)  warming. 
C)  oxygenation. 
D)  salinity increase. 
E)  eutrophication. 
A)  antibiotic resistance. 
B)  warming. 
C)  oxygenation. 
D)  salinity increase. 
E)  eutrophication.

Question 8

Why is moist heat more efficient at killing microbes than dry heat? How does an autoclave kill microbes so efficiently?

Accepted Answer

Moist heat is a more effective killer th

Question 9

The conditions used in an autoclave may be reproduced at home in

Accepted Answer

A)  a rice cooker. 
B)  a double-boiler. 
C)  a microwave. 
D)  a pressure cooker. 
E)  boiling water. 
A)  a rice cooker. 
B)  a double-boiler. 
C)  a microwave. 
D)  a pressure cooker. 
E)  boiling water.

Question 10

Describe the studies with Salmonella that showed that in vitro conditions do not always model what happens in vivo (in this case in the phagocytic vacuole).

Accepted Answer

Protein profiles were obtained in vitro

Question 11

Runoff from agricultural fields, lawns, and golf courses can cause an overgrowth of microbes due to

Accepted Answer

A)  eutrophication. 
B)  starvation response. 
C)  oligotrophy. 
D)  antisepsis. 
E)  pasteurization. 
A)  eutrophication. 
B)  starvation response. 
C)  oligotrophy. 
D)  antisepsis. 
E)  pasteurization.

Question 12

What is depicted in the following figure?

Accepted Answer

A)  Antibiotic production has inhibited bacterial growth. 
B)  A bacteriophage has preyed on the bacterial colonies. 
C)  Weak acid production has inhibited bacterial growth. 
D)  A biofilm has become resistant to disinfectants. 
E)  Starving cells have undergone programmed cell death. 
A)  Antibiotic production has inhibited bacterial growth. 
B)  A bacteriophage has preyed on the bacterial colonies. 
C)  Weak acid production has inhibited bacterial growth. 
D)  A biofilm has become resistant to disinfectants. 
E)  Starving cells have undergone programmed cell death.

Question 13

Human pathogens are

Accepted Answer

A)  halophilic. 
B)  psychrophilic. 
C)  mesophilic. 
D)  thermophilic. 
E)  extreme thermophilic. 
A)  halophilic. 
B)  psychrophilic. 
C)  mesophilic. 
D)  thermophilic. 
E)  extreme thermophilic.

Question 14

Why are thermophiles able to survive at temperatures that would quickly kill most mesophiles? Describe at least three adaptations.

Accepted Answer

Thermophilic proteins are more stable du

Question 15

During the starvation response, only a limited number of organisms can

Accepted Answer

A)  retool transport systems for the uptake of different nutrients. 
B)  form metabolically inactive endospores. 
C)  protect against reactive oxygen species. 
D)  protect against temperature extremes. 
E)  protect against pH extremes. 
A)  retool transport systems for the uptake of different nutrients. 
B)  form metabolically inactive endospores. 
C)  protect against reactive oxygen species. 
D)  protect against temperature extremes. 
E)  protect against pH extremes.

Question 16

The membrane needs to remain ________ so that it can expand as cells grow larger and so that proteins needed for solute transport can be inserted into the membrane.

Accepted Answer

A)  rigid 
B)  warm 
C)  fluid 
D)  hypertonic 
E)  polarized 
A)  rigid 
B)  warm 
C)  fluid 
D)  hypertonic 
E)  polarized

Question 17

What is biocontrol? Describe two examples.

Accepted Answer

Answers will vary. Biocontrol is the use

Question 18

A useful biocontrol alternative to antibiotics for treatment of biofilms that can potentially lead to chronic infections is

Accepted Answer

A)  phenolics. 
B)  high temperatures and pressures. 
C)  commercial disinfectants. 
D)  x-rays. 
E)  bacteriophages. 
A)  phenolics. 
B)  high temperatures and pressures. 
C)  commercial disinfectants. 
D)  x-rays. 
E)  bacteriophages.

Question 19

Which of the following are commonly used to control microbial growth in foods?

Accepted Answer

A)  weak acids 
B)  strong acids 
C)  weak bases 
D)  strong bases 
E)  enzymes 
A)  weak acids 
B)  strong acids 
C)  weak bases 
D)  strong bases 
E)  enzymes

Question 20

Most bacteria require water activity to be greater than

Accepted Answer

A)  0.10. 
B)  0.25. 
C)  0.74. 
D)  0.91. 
E)  1.0. 
A)  0.10. 
B)  0.25. 
C)  0.74. 
D)  0.91. 
E)  1.0.

Exam 5: Environmental Influences and Control of Microbial Growth

Which of the following is true of microbes and their membranes?

The use of oxygen as the terminal electron acceptor is called

How are some organisms able to survive temporary exposures to elevated temperatures?

The fastest growth rate for a species occurs at temperatures where a cell's ________ work most efficiently.

Which of the following grows in the indicated pH range shown in the figure below?

Psychrophiles favor the cold, since their membranes are more fluid at low temperature as a result of the high proportion of ________ present.

Cyanobacterial blooms such as those shown in the figure below are typically due to human-caused

Why is moist heat more efficient at killing microbes than dry heat? How does an autoclave kill microbes so efficiently?

The conditions used in an autoclave may be reproduced at home in

Describe the studies with Salmonella that showed that in vitro conditions do not always model what happens in vivo (in this case in the phagocytic vacuole).

Runoff from agricultural fields, lawns, and golf courses can cause an overgrowth of microbes due to

What is depicted in the following figure?

Human pathogens are

Why are thermophiles able to survive at temperatures that would quickly kill most mesophiles? Describe at least three adaptations.

During the starvation response, only a limited number of organisms can

The membrane needs to remain ________ so that it can expand as cells grow larger and so that proteins needed for solute transport can be inserted into the membrane.

What is biocontrol? Describe two examples.

A useful biocontrol alternative to antibiotics for treatment of biofilms that can potentially lead to chronic infections is

Which of the following are commonly used to control microbial growth in foods?

Most bacteria require water activity to be greater than

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

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