Question 1

Biofilms

Accepted Answer

A) are a haphazard mixture of bacteria. 
B) are a polysaccharide-encased community of microorganisms. 
C) may enhance bioremediation efforts. 
D) may protect organisms against harmful chemicals. 
E) are a polysaccharide-encased community of microorganisms,may enhance bioremediation efforts,AND may protect organisms against harmful chemicals. 
A) are a haphazard mixture of bacteria. 
B) are a polysaccharide-encased community of microorganisms. 
C) may enhance bioremediation efforts. 
D) may protect organisms against harmful chemicals. 
E) are a polysaccharide-encased community of microorganisms,may enhance bioremediation efforts,AND may protect organisms against harmful chemicals.

Question 2

A pure culture in exponential growth phase has a bacterial concentration of 6.4 x 108 cells/ml.If the bacterium has a generation time of 1 h,how long ago was the cell concentration 8.0 x 107 cells/ml?

Accepted Answer

A) 1 h 
B) 2 h 
C) 3 h 
D) 4 h 
A) 1 h 
B) 2 h 
C) 3 h 
D) 4 h

Question 3

In microbiology,growth usually refers to an increase in size of the bacteria.

Accepted Answer

A) True 
 B)False

Question 4

A single bacterial cell may multiply to form a visible colony.

Accepted Answer

A) True 
 B)False

Question 5

Organisms that are indifferent to the presence of oxygen and do not use it are

Accepted Answer

A) aerotolerant anaerobes. 
B) facultative anaerobes. 
C) obligate aerobes. 
D) microaerophiles. 
A) aerotolerant anaerobes. 
B) facultative anaerobes. 
C) obligate aerobes. 
D) microaerophiles.

Question 6

Prokaryotic cells divide by a process known as

Accepted Answer

A) conjugation. 
B) mitosis. 
C) binary fusion. 
D) binary fission. 
A) conjugation. 
B) mitosis. 
C) binary fusion. 
D) binary fission.

Question 7

The enzymes that deal with toxic oxygen-containing molecules is/are

Accepted Answer

A) glycolase. 
B) superoxide dismutase. 
C) catalase. 
D) cytochrome oxidase. 
E) superoxide dismutase AND catalase. 
A) glycolase. 
B) superoxide dismutase. 
C) catalase. 
D) cytochrome oxidase. 
E) superoxide dismutase AND catalase.

Question 8

Organisms that use organic molecules as their source of carbon are called

Accepted Answer

A) chemotrophs. 
B) organoheterotrophs. 
C) heterotrophs. 
D) autotrophs. 
A) chemotrophs. 
B) organoheterotrophs. 
C) heterotrophs. 
D) autotrophs.

Question 9

Peptone

Accepted Answer

A) refers to a hydrolysate of carbohydrates used in growth media. 
B) refers to a hydrolysate of proteins used in growth media. 
C) consists of a water extract of beef. 
D) consists of a mix of monosaccharides and oligosaccharides. 
E) refers to a hydrolysate of proteins used in growth media AND consists of a water extract of beef. 
A) refers to a hydrolysate of carbohydrates used in growth media. 
B) refers to a hydrolysate of proteins used in growth media. 
C) consists of a water extract of beef. 
D) consists of a mix of monosaccharides and oligosaccharides. 
E) refers to a hydrolysate of proteins used in growth media AND consists of a water extract of beef.

Question 10

The optimal temperature for most human pathogens might be expected to range from

Accepted Answer

A) 35-40$\circ$C. 
B) 20-45$\circ$C. 
C) 15-25$\circ$C. 
D) 93-98.6$\circ$C. 
A) 35-40$\circ$C. 
B) 20-45$\circ$C. 
C) 15-25$\circ$C. 
D) 93-98.6$\circ$C.

Question 11

During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?

Accepted Answer

A) Lag phase 
B) Exponential phase 
C) Stationary phase 
D) Late log phase 
A) Lag phase 
B) Exponential phase 
C) Stationary phase 
D) Late log phase

Question 12

Agar

Accepted Answer

A) is a useful nutrient source for most bacteria. 
B) is a hydrolysate of proteins. 
C) stays liquid through the typical range of incubation temperatures. 
D) has chemical and physical properties that make it almost ideal for solidifying media. 
A) is a useful nutrient source for most bacteria. 
B) is a hydrolysate of proteins. 
C) stays liquid through the typical range of incubation temperatures. 
D) has chemical and physical properties that make it almost ideal for solidifying media.

Question 13

Bacteria may be stored

Accepted Answer

A) on a slant in the refrigerator. 
B) frozen in glycerol solution. 
C) freeze-dried. 
D) in broth at 37$\circ$C. 
E) on a slant in the refrigerator,frozen in glycerol solution,AND freeze-dried. 
A) on a slant in the refrigerator. 
B) frozen in glycerol solution. 
C) freeze-dried. 
D) in broth at 37$\circ$C. 
E) on a slant in the refrigerator,frozen in glycerol solution,AND freeze-dried.

Question 14

Organisms that require gaseous oxygen for metabolism are referred to as

Accepted Answer

A) facultative aerobes. 
B) obligate aerobes. 
C) facultative anaerobes. 
D) microaerophiles. 
A) facultative aerobes. 
B) obligate aerobes. 
C) facultative anaerobes. 
D) microaerophiles.

Question 15

You are working in a clinical laboratory in a hospital setting.You're handed a throat swab from a patient.You are told specifically that the physician is only interested in the presence and type of Gram positive cells.Identification isn't the main goal here-just a first step to work towards determining what Gram positive cells might be there.What might you do first to go about working towards this goal?

Accepted Answer

A) Perform a Gram stain. 
B) Streak the sample for isolation on a tryptic soy agar general purpose medium plate. 
C) Streak the sample for isolation on a medium that is selective for Gram positive cells while suppressing Gram negative cell growth. 
D) Grow the microbes on the swab by inoculating a tryptic soy broth liquid medium tube. 
E) Perform an acid-fast stain. 
A) Perform a Gram stain. 
B) Streak the sample for isolation on a tryptic soy agar general purpose medium plate. 
C) Streak the sample for isolation on a medium that is selective for Gram positive cells while suppressing Gram negative cell growth. 
D) Grow the microbes on the swab by inoculating a tryptic soy broth liquid medium tube. 
E) Perform an acid-fast stain.

Question 16

The optimum pH for growth of most species of bacteria is

Accepted Answer

A) pH 5. 
B) pH 7. 
C) pH 9. 
D) pH 6. 
A) pH 5. 
B) pH 7. 
C) pH 9. 
D) pH 6.

Question 17

Generally the proteins of thermophiles

Accepted Answer

A) resist denaturation. 
B) react more efficiently with DNA. 
C) are easily denatured. 
D) have a particular amino acid sequence that restricts bond formation. 
E) are easily denatured AND have a particular amino acid sequence that restricts bond formation. 
A) resist denaturation. 
B) react more efficiently with DNA. 
C) are easily denatured. 
D) have a particular amino acid sequence that restricts bond formation. 
E) are easily denatured AND have a particular amino acid sequence that restricts bond formation.

Question 18

Which of the following is/are obligate aerobes?

Accepted Answer

A) Clostridium botulinum 
B) Escherichia coli 
C) Micrococcus luteus 
D) Helicobacter pylori 
A) Clostridium botulinum 
B) Escherichia coli 
C) Micrococcus luteus 
D) Helicobacter pylori

Question 19

During which phase of growth are bacteria most susceptible to antibiotics?

Accepted Answer

A) Lag 
B) Stationary 
C) Exponential (log) 
D) Decline 
A) Lag 
B) Stationary 
C) Exponential (log) 
D) Decline

Question 20

You are in charge of water quality for your city's water treatment plant.Of the methods at your disposal,which will be the most efficient and cheapest method of determining the number of viable bacteria in the water coming out of your plant?

Accepted Answer

A) Direct counts using a microscope and a counting chamber. 
B) Using a Coulter counter machine. 
C) Performing serial dilutions of your samples and doing spread plate counts. 
D) Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation. 
E) Biochemical analysis of secondary metabolites in the water that are given off by bacteria. 
A) Direct counts using a microscope and a counting chamber. 
B) Using a Coulter counter machine. 
C) Performing serial dilutions of your samples and doing spread plate counts. 
D) Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation. 
E) Biochemical analysis of secondary metabolites in the water that are given off by bacteria.

Exam 4: Dynamics of Prokaryotic Growth

Biofilms

A pure culture in exponential growth phase has a bacterial concentration of 6.4 x 108 cells/ml.If the bacterium has a generation time of 1 h,how long ago was the cell concentration 8.0 x 107 cells/ml?

In microbiology,growth usually refers to an increase in size of the bacteria.

A single bacterial cell may multiply to form a visible colony.

Organisms that are indifferent to the presence of oxygen and do not use it are

Prokaryotic cells divide by a process known as

The enzymes that deal with toxic oxygen-containing molecules is/are

Organisms that use organic molecules as their source of carbon are called

Peptone

The optimal temperature for most human pathogens might be expected to range from

During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?

Agar

Bacteria may be stored

Organisms that require gaseous oxygen for metabolism are referred to as

The optimum pH for growth of most species of bacteria is

Generally the proteins of thermophiles

Which of the following is/are obligate aerobes?

During which phase of growth are bacteria most susceptible to antibiotics?

You are in charge of water quality for your city's water treatment plant.Of the methods at your disposal,which will be the most efficient and cheapest method of determining the number of viable bacteria in the water coming out of your plant?

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Control of Microbial Growth

Metabolism: Fueling Cell Growth

The Blueprint of Life, From DNA to Protein

Bacterial Genetics

Biotechnology and Recombinant DNA

Identification and Classification of Prokaryotic Organisms

The Diversity of Prokaryotic Organisms

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunologic Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Genitourinary Tract Infections

Filters

A pure culture in exponential growth phase has a bacterial concentration of 6.4 x 10⁸ cells/ml.If the bacterium has a generation time of 1 h,how long ago was the cell concentration 8.0 x 10⁷ cells/ml?