Question 1

Spoilage of food can alter the odor or taste of the food.Which of the following statements correctly matches a pathway to the spoilage that results?

Accepted Answer

A)   Acidic fermentation leads to a bitter flavor.
B)   Alkaline products from microbial metabolism leads to a sour flavor.
C)   Oxidation of fats leads to rancidity.
D)   Decomposition of proteins and amino acids leads to a salty flavor.E) A) and B)
F) None of the above

Question 2

What role do microbes play in the increase of atmospheric carbon dioxide seen in this graph?

Accepted Answer

A)   Microbial populations have been increasing since 1800,and this increase has led to increases in carbon dioxide levels.
B)   Microbes convert other elements in carbon dioxide and have caused increases in carbon dioxide levels.
C)   Microbial populations have been decreasing since 1800,and this decrease has led to increases in carbon dioxide levels.
D)   Microbes fix carbon dioxide and help limit increases of carbon dioxide in the atmosphere.E) None of the above
F) All of the above

Question 3

Which of the following statements correctly describes the relationship between biochemical oxygen demand (BOD) ,heterotrophic bacteria,and fish?

Accepted Answer

A)   The presence of fish increases the number of heterotrophic bacteria in an area,which decreases the BOD.
B)   Increases in the number of heterotrophic bacteria decrease the BOD,which decreases the number of fish.
C)   The BOD of a marine environment is independent of populations of heterotrophic bacteria and fish.
D)   Heterotrophic bacteria generate oxygen,which increases the BOD and increases the number of fish.E) A) and B)
F) A) and C)

Question 4

An end result of mixed-acid fermentation products being converted into a gas in cattle is production of the greenhouse gas ________.

Accepted Answer

The answer of An end result of mixed-acid fermentation products...

Question 5

A new species of human gut bacteria is discovered.Scientists find that during the process of breaking down and utilizing undigested plant fibers,the bacteria also produces a vitamin that is absorbed by humans.The relationship described is an example of

Accepted Answer

A)   amensalism.
B)   parasitism.
C)   commensalism.
D)   mutualism.E) A) and D)
F) None of the above

Question 6

What is the function of aeration basins at wastewater treatment facilities?

Accepted Answer

A)   Aeration encourages fermentation.
B)   Aeration maximizes microbial breakdown of pollutants to carbon dioxide and nitrates.
C)   Aeration limits free-floating populations of bacteria.
D)   Aeration allows filamentous methanogens to metabolize acetate within the interior of flocs.E) B) and C)
F) None of the above

Question 7

When carbon- and nitrogen-rich wastes are released into aquatic environments

Accepted Answer

A)   algae populations decrease.
B)   fish populations increase.
C)   invertebrate populations increase.
D)   bacterial populations increase.E) A) and B)
F) B) and D)

Question 8

CASE HISTORY
In the fall of 2008,several individuals,many of them children,were sickened from the common food pathogen Salmonella enterica.Most infected individuals developed diarrhea,fever,and abdominal cramps 12-72 hours after infection,and symptoms lasted 4-7 days.Over the next six months,cases were reported from nearly all U.S.states,ultimately totaling 700 people.The curve of the outbreak (cases rising and then falling)followed the profile of a single-source epidemic,in which all infections are ultimately traced to one source.All cases of illness showed a common strain of the pathogen S.enterica serovar typhimurium.CDC researchers investigated the outbreak by comparing the food intake histories of ill persons with that of matched controls.They found a statistical association between illness and intake of peanut butter,eventually narrowed to a specific brand of peanut butter sold to institutions.As the epidemic grew,cases emerged in which the contaminated food product turned out to be crackers filled with peanut butter cream.Ultimately,the peanut butter and cream were traced back to peanuts from a single factory in Georgia.
Describe some of the chemical and physical approaches normally used in the production and storage of a food like peanut butter,which are designed to reduce the possibility of outbreaks such as this one.Give an example of a common scenario in which these precautions might fail.

Accepted Answer

Students should choose methods that are ...

Question 9

In a wastewater treatment plant,the removal of large,solid debris such as sticks and dead animals occurs during ________ treatment.

Accepted Answer

The answer of In a wastewater treatment plant,the removal of...

Question 10

Bacteriocins are molecules that are produced by

Accepted Answer

A)   some bacteria and prevent pathogens from adhering to the gut lining.
B)   methanogens and cause flatulence in cows.
C)   digestive microbes in termites and allow digestion of cellulose.
D)   viruses and increase the virulence of zoonotic diseases.E) A) and B)
F) A) and C)

Question 11

Bacteria and archaea are the only organisms capable of converting the element ________ between its oxidation states.

Accepted Answer

The answer of Bacteria and archaea are the only organisms...

Question 12

This figure shows restriction-digested DNA fragments from Salmonella enterica that have been separated by electrophoresis.The Salmonella enterica was isolated from individuals with illness and two jars of peanut butter.Which of the following accurately describes these fragments?

Accepted Answer

A)   These fragments indicate food contamination in both jars of peanut butter.
B)   These fragments indicate no relationship between the ill individuals and peanut butter.
C)   These fragments indicate that individuals became ill after eating peanut butter from Jar 2.
D)   These fragments indicate food contamination in Jar 1,but not in Jar 2.E) B) and C)
F) A) and C)

Question 13

If bacteria and archaea are removed from an ecosystem,which of the following environmental services would be absent?

Accepted Answer

A)   nitrogen fixation
B)   capture of energy from sunlight
C)   decomposition of dead matter
D)   dissimilation of biomass by respirationE) B) and C)
F) A) and B)

Question 14

A high school student visiting Lake Erie reads a sign indicating that it is unsafe to swim at a beach because of a toxin called microcystin.The student does some research and finds the following relationship between fertilizer,algae,heterotrophic bacteria,and fish: fertilizer runoff causes

Accepted Answer

A)   algal blooms,which lead to an increase in heterotrophic bacteria and a decrease in fish.
B)   increases in heterotrophic bacteria,which leads to an increase in algal blooms and a decrease in fish.
C)   increases in fish populations,which leads to decreases in heterotrophic bacteria and algae populations.
D)   algal blooms,which lead to a decrease in heterotrophic bacteria and an increase in fish.E) A) and D)
F) A) and C)

Question 15

Describe any differences between the primary producers in the ocean versus the primary producers on land.

Accepted Answer

Primary producers fix carbon dioxide and...

Question 16

Which of the following illustrates a positive interaction between human microbiota and the immune system?

Accepted Answer

A)   down-regulation of cytokines within the colon
B)   production of short-chain acids within the colon
C)   conversion of hydrogen gas and carbon dioxide into methane
D)   secretion of acids that decrease pH within the colonE) B) and D)
F) A) and B)

Question 17

Curds from milk fermentation are particularly valuable because they

Accepted Answer

A)   are a source of concentrated protein.
B)   contain more vitamins than milk.
C)   contain acetic acid that can be used to preserve other foods.
D)   have an indefinite shelf life and do not require refrigeration.E) B) and D)
F) A) and C)

Question 18

Explain how the availability of oxygen in soil determines how microbes utilize organic compounds supplied by other organisms.

Accepted Answer

When oxygen is available,oxygen is used ...

Question 19

Shifting a cow's diet results in a(n)

Accepted Answer

A)   change in the pathway of digestion through the cow's four stomach chambers.
B)   change in the microbial populations present within the cow's gut.
C)   increase in antibiotic-resistant bacteria found in the environment.
D)   decrease in the amount of water and short-chain acids absorbed in the omasum.E) None of the above
F) A) and B)

Question 20

High salt concentrations limit the growth of microbes adapted to freshwater conditions because

Accepted Answer

A)   salt prevents microbes from using oxygen as an electron acceptor during aerobic cellular respiration.
B)   high salt concentrations increase the temperature of the environment above the range at which most microbes can survive.
C)   freshwater is a hypotonic solution and microbes living in freshwater do not have a need for mechanisms to reduce water loss.
D)   a high salt concentration leads to a sharp decline in the pH of the environment.E) A) and C)
F) All of the above

Exam 27: Environmental and Food Microbiology

Shifting a cow's diet results in a(n)

Correct Answer
verified

What role do microbes play in the increase of atmospheric carbon dioxide seen in this graph?

Correct Answer
verified

Bacteria and archaea are the only organisms capable of converting the element ________ between its oxidation states.

Correct Answer
verified

Describe any differences between the primary producers in the ocean versus the primary producers on land.

Correct Answer
verified
Primary producers fix carbon dioxide and...
View Answer

Explain how the availability of oxygen in soil determines how microbes utilize organic compounds supplied by other organisms.

Correct Answer
verified
When oxygen is available,oxygen is used ...
View Answer

Spoilage of food can alter the odor or taste of the food.Which of the following statements correctly matches a pathway to the spoilage that results?

Correct Answer
verified

A high school student visiting Lake Erie reads a sign indicating that it is unsafe to swim at a beach because of a toxin called microcystin.The student does some research and finds the following relationship between fertilizer,algae,heterotrophic bacteria,and fish: fertilizer runoff causes

Correct Answer
verified

Which of the following illustrates a positive interaction between human microbiota and the immune system?

Correct Answer
verified

What is the function of aeration basins at wastewater treatment facilities?

Correct Answer
verified

In a wastewater treatment plant,the removal of large,solid debris such as sticks and dead animals occurs during ________ treatment.

Correct Answer
verified

Bacteriocins are molecules that are produced by

Correct Answer
verified

This figure shows restriction-digested DNA fragments from Salmonella enterica that have been separated by electrophoresis.The Salmonella enterica was isolated from individuals with illness and two jars of peanut butter.Which of the following accurately describes these fragments?

Correct Answer
verified

When carbon- and nitrogen-rich wastes are released into aquatic environments

Correct Answer
verified

Curds from milk fermentation are particularly valuable because they

Correct Answer
verified

A new species of human gut bacteria is discovered.Scientists find that during the process of breaking down and utilizing undigested plant fibers,the bacteria also produces a vitamin that is absorbed by humans.The relationship described is an example of

Correct Answer
verified

Correct Answer
verified
Students should choose methods that are ...
View Answer

High salt concentrations limit the growth of microbes adapted to freshwater conditions because

Correct Answer
verified

If bacteria and archaea are removed from an ecosystem,which of the following environmental services would be absent?

Correct Answer
verified

Which of the following statements correctly describes the relationship between biochemical oxygen demand (BOD) ,heterotrophic bacteria,and fish?

Correct Answer
verified

An end result of mixed-acid fermentation products being converted into a gas in cattle is production of the greenhouse gas ________.

Correct Answer
verified

Exam 27: Environmental and Food Microbiology

Shifting a cow's diet results in a(n)

Correct AnswerverifiedShow Answer

What role do microbes play in the increase of atmospheric carbon dioxide seen in this graph?

Correct AnswerverifiedShow Answer

Bacteria and archaea are the only organisms capable of converting the element ________ between its oxidation states.

Correct AnswerverifiedShow Answer

Describe any differences between the primary producers in the ocean versus the primary producers on land.

Correct AnswerverifiedPrimary producers fix carbon dioxide and...View AnswerShow Answer

Explain how the availability of oxygen in soil determines how microbes utilize organic compounds supplied by other organisms.

Correct AnswerverifiedWhen oxygen is available,oxygen is used ...View AnswerShow Answer

Spoilage of food can alter the odor or taste of the food.Which of the following statements correctly matches a pathway to the spoilage that results?

Correct AnswerverifiedShow Answer

A high school student visiting Lake Erie reads a sign indicating that it is unsafe to swim at a beach because of a toxin called microcystin.The student does some research and finds the following relationship between fertilizer,algae,heterotrophic bacteria,and fish: fertilizer runoff causes

Correct AnswerverifiedShow Answer

Which of the following illustrates a positive interaction between human microbiota and the immune system?

Correct AnswerverifiedShow Answer

What is the function of aeration basins at wastewater treatment facilities?

Correct AnswerverifiedShow Answer

In a wastewater treatment plant,the removal of large,solid debris such as sticks and dead animals occurs during ________ treatment.

Correct AnswerverifiedShow Answer

Bacteriocins are molecules that are produced by

Correct AnswerverifiedShow Answer

This figure shows restriction-digested DNA fragments from Salmonella enterica that have been separated by electrophoresis.The Salmonella enterica was isolated from individuals with illness and two jars of peanut butter.Which of the following accurately describes these fragments?

Correct AnswerverifiedShow Answer

When carbon- and nitrogen-rich wastes are released into aquatic environments

Correct AnswerverifiedShow Answer

Curds from milk fermentation are particularly valuable because they

Correct AnswerverifiedShow Answer

A new species of human gut bacteria is discovered.Scientists find that during the process of breaking down and utilizing undigested plant fibers,the bacteria also produces a vitamin that is absorbed by humans.The relationship described is an example of

Correct AnswerverifiedShow Answer

Correct AnswerverifiedStudents should choose methods that are ...View AnswerShow Answer

High salt concentrations limit the growth of microbes adapted to freshwater conditions because

Correct AnswerverifiedShow Answer

If bacteria and archaea are removed from an ecosystem,which of the following environmental services would be absent?

Correct AnswerverifiedShow Answer

Which of the following statements correctly describes the relationship between biochemical oxygen demand (BOD) ,heterotrophic bacteria,and fish?

Correct AnswerverifiedShow Answer

An end result of mixed-acid fermentation products being converted into a gas in cattle is production of the greenhouse gas ________.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Primary producers fix carbon dioxide and...
View Answer

Correct Answer
verified
When oxygen is available,oxygen is used ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Students should choose methods that are ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified