Question 1

During which stage of bacterial growth is the culture growing exponentially?

Accepted Answer

A)  lag phase 
B)  log phase 
C)  growth phase 
D)  stationary phase 
E)  death phase 
A)  lag phase 
B)  log phase 
C)  growth phase 
D)  stationary phase 
E)  death phase

Question 2

MacConkey medium contains bile salts, crystal violet, lactose, and the pH indicator neutral red. Some organisms can ferment lactose, producing acids as a by-product. Is this medium likely to be selective and/or differential? Explain.

Accepted Answer

Since MacConkey contains bile salts and

Question 3

Which of the following statements is FALSE about the E. coli phosphotransferase system (PTS)?

Accepted Answer

A)  Enzyme II components are specific to the substrates being transported. 
B)  The substrate is phosphorylated during transport by PTS, making it different from the external substrate; thus, the substrate always travels down its concentration gradient. 
C)  The phosphate group transferred to the sugar comes from phosphoenolpyruvate (PEP). 
D)  The PTS transport requires energy in the form of ATP. 
E)  The system has a modular design that accommodates different substrates. 
A)  Enzyme II components are specific to the substrates being transported. 
B)  The substrate is phosphorylated during transport by PTS, making it different from the external substrate; thus, the substrate always travels down its concentration gradient. 
C)  The phosphate group transferred to the sugar comes from phosphoenolpyruvate (PEP). 
D)  The PTS transport requires energy in the form of ATP. 
E)  The system has a modular design that accommodates different substrates.

Question 4

Which of the following can consume glucose and, in the absence of oxygen, break it down into ethanol and carbon dioxide gas?

Accepted Answer

A)  E. coli 
B)  phototrophs 
C)  yeast 
D)  archaea 
E)  nitrogen fixers 
A)  E. coli 
B)  phototrophs 
C)  yeast 
D)  archaea 
E)  nitrogen fixers

Question 5

In order to grow unculturable environmental microbes, Kim Lewis and colleagues derived the iChip. What is the purpose of this device?

Accepted Answer

A)  Antibiotics from the environment could pass into the chamber. 
B)  Gram-positive organisms could not pass the semipermeable membrane. 
C)  The semipermeable membranes let environmental organisms into the agar. 
D)  Organisms from the environment grew in the chamber. 
E)  Nutrients and growth factors made by organisms in the soil diffused into the chamber. 
A)  Antibiotics from the environment could pass into the chamber. 
B)  Gram-positive organisms could not pass the semipermeable membrane. 
C)  The semipermeable membranes let environmental organisms into the agar. 
D)  Organisms from the environment grew in the chamber. 
E)  Nutrients and growth factors made by organisms in the soil diffused into the chamber.

Question 6

Which of the following is the best technique for counting only viable cells?

Accepted Answer

A)  direct microscopic count 
B)  spread plate 
C)  spectrophotometer 
D)  chemostat 
E)  dry weight measurements 
A)  direct microscopic count 
B)  spread plate 
C)  spectrophotometer 
D)  chemostat 
E)  dry weight measurements

Question 7

Why can't most organisms use the nitrogen gas that is so prevalent in the atmosphere? How do these organisms acquire a usable form of nitrogen?

Accepted Answer

Nitrogen gas has triple bonds holding th

Question 8

Using the figure below, explain the function of stages 2 and 3 in biofilm development and how they affect biofilm growth, function, and treatment.

Accepted Answer

The establishment of microcolonies trigg

Question 9

A problem with ________ of cell number is that dead cells also scatter light.

Accepted Answer

A)  direct microscopic counts 
B)  viable counts 
C)  spread plate counts 
D)  pour plate counts 
E)  optical density measurements 
A)  direct microscopic counts 
B)  viable counts 
C)  spread plate counts 
D)  pour plate counts 
E)  optical density measurements

Question 10

What are some specific problems that biofilms can cause in the medical field, and why are they so difficult to prevent and destroy?

Accepted Answer

Biofilms can grow in medical devices suc

Question 11

Bacteria divide at a constant time interval called the

Accepted Answer

A)  generation time. 
B)  growth time. 
C)  growth rate. 
D)  exponential rate. 
E)  log phase. 
A)  generation time. 
B)  growth time. 
C)  growth rate. 
D)  exponential rate. 
E)  log phase.

Question 12

Which of the following occurs when a sessile biofilm (or a part of it) begins to starve or experiences oxygen depletion?

Accepted Answer

A)  attachment 
B)  quorum sensing 
C)  EPS production 
D)  dispersal 
E)  biofilm maturation 
A)  attachment 
B)  quorum sensing 
C)  EPS production 
D)  dispersal 
E)  biofilm maturation

Question 13

Some bacteria form environmentally resistant dormant forms called

Accepted Answer

A)  endospores. 
B)  heterocysts. 
C)  colonies. 
D)  hyphae. 
E)  actinomycetes. 
A)  endospores. 
B)  heterocysts. 
C)  colonies. 
D)  hyphae. 
E)  actinomycetes.

Question 14

Compare and contrast the ABC transporters and group translocation in terms of energy requirements and concentration gradients.

Accepted Answer

Both forms of transport require energy.

Question 15

Which of the following is NOT true about the substrate-binding protein (SBP) of the ABC transport system?

Accepted Answer

A)  It floats in the periplasm of Gram-negative cells. 
B)  It is tethered to the cell surface in Gram-positive cells. 
C)  It binds to the periplasmic face of the channel and releases the solute. 
D)  It snags the appropriate solute. 
E)  It is required for both the uptake and efflux systems. 
A)  It floats in the periplasm of Gram-negative cells. 
B)  It is tethered to the cell surface in Gram-positive cells. 
C)  It binds to the periplasmic face of the channel and releases the solute. 
D)  It snags the appropriate solute. 
E)  It is required for both the uptake and efflux systems.

Question 16

Which of the following intercalates between DNA bases, causing dead cells to stain red under a fluorescence scope?

Accepted Answer

A)  propidium iodide 
B)  syto-9 
C)  bile salt 
D)  crystal violet 
E)  safranin 
A)  propidium iodide 
B)  syto-9 
C)  bile salt 
D)  crystal violet 
E)  safranin

Question 17

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

Accepted Answer

A)  lag 
B)  early log 
C)  late log 
D)  stationary 
E)  death 
A)  lag 
B)  early log 
C)  late log 
D)  stationary 
E)  death

Question 18

Which of the following is true of all biofilms?

Accepted Answer

A)  They only contain a single species. 
B)  The EPS are composed of proteins. 
C)  Cells in the biofilm are dormant until the bacteria leave the biofilm. 
D)  The EPS is secreted by the bacteria. 
E)  It is a continuous monolayer surface deposit. 
A)  They only contain a single species. 
B)  The EPS are composed of proteins. 
C)  Cells in the biofilm are dormant until the bacteria leave the biofilm. 
D)  The EPS is secreted by the bacteria. 
E)  It is a continuous monolayer surface deposit.

Question 19

Why do some members of a biofilm community live deep within the biofilm?

Accepted Answer

A)  They are not flagellated. 
B)  They produce fewer exopolysaccharides. 
C)  They were the first organisms to initiate attachment. 
D)  Antibiotics do not penetrate deep into biofilms. 
E)  Oxygen does not penetrate deep into biofilms. 
A)  They are not flagellated. 
B)  They produce fewer exopolysaccharides. 
C)  They were the first organisms to initiate attachment. 
D)  Antibiotics do not penetrate deep into biofilms. 
E)  Oxygen does not penetrate deep into biofilms.

Question 20

Metabolism of a microbe is best examined by growing the organism in a

Accepted Answer

A)  defined medium. 
B)  complex medium. 
C)  spread plate. 
D)  pour plate. 
E)  cell culture. 
A)  defined medium. 
B)  complex medium. 
C)  spread plate. 
D)  pour plate. 
E)  cell culture.

Exam 4: Bacterial Culture, Growth, and Development

During which stage of bacterial growth is the culture growing exponentially?

MacConkey medium contains bile salts, crystal violet, lactose, and the pH indicator neutral red. Some organisms can ferment lactose, producing acids as a by-product. Is this medium likely to be selective and/or differential? Explain.

Which of the following statements is FALSE about the E. coli phosphotransferase system (PTS)?

Which of the following can consume glucose and, in the absence of oxygen, break it down into ethanol and carbon dioxide gas?

In order to grow unculturable environmental microbes, Kim Lewis and colleagues derived the iChip. What is the purpose of this device?

Which of the following is the best technique for counting only viable cells?

Why can't most organisms use the nitrogen gas that is so prevalent in the atmosphere? How do these organisms acquire a usable form of nitrogen?

Using the figure below, explain the function of stages 2 and 3 in biofilm development and how they affect biofilm growth, function, and treatment.

A problem with ________ of cell number is that dead cells also scatter light.

What are some specific problems that biofilms can cause in the medical field, and why are they so difficult to prevent and destroy?

Bacteria divide at a constant time interval called the

Which of the following occurs when a sessile biofilm (or a part of it) begins to starve or experiences oxygen depletion?

Some bacteria form environmentally resistant dormant forms called

Compare and contrast the ABC transporters and group translocation in terms of energy requirements and concentration gradients.

Which of the following is NOT true about the substrate-binding protein (SBP) of the ABC transport system?

Which of the following intercalates between DNA bases, causing dead cells to stain red under a fluorescence scope?

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

Which of the following is true of all biofilms?

Why do some members of a biofilm community live deep within the biofilm?

Metabolism of a microbe is best examined by growing the organism in a

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Environmental Influences and Control of Microbial Growth

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

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Antimicrobial Therapy

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