Question 1

In _____,bacteria return nitrogen to the atmosphere by converting nitrates to N2.

Accepted Answer

A)   nitrogen fixing
B)   nitrification
C)   denitrification
D)   respiration
E)   transpirationF) A) and B)
G) A) and D) C

Question 2

An example of a keystone species is a root-associated fungus that conifer trees need in order to survive and that supply food for rodents.

Accepted Answer

A) True 
 B)False

Question 3

An ecosystem is defined as

Accepted Answer

A)   all of the individuals of the same species living in an area.
B)   all of the members of all of the species living in an area.
C)   the physical place and environmental surroundings in which individual organisms live.
D)   the set of environmental resources that each organism requires for survival, growth, reproduction, etc.
E)   the sum of living organisms and nonliving environmental components in an area.F) B) and C)
G) A) and B)

Question 4

Mycorrhizal fungi obtain food from plants in exchange for water and nutrients.This is an example of

Accepted Answer

A)   herbivory.
B)   commensalism.
C)   predation.
D)   mutualism.
E)   parasitism.F) C) and D)
G) D) and E)

Question 5

The decline of the sea otter population in the Pacific Northwest has been attributed to

Accepted Answer

A)   pollution from an oil spill.
B)   a genetic mutation causing a decrease of fertility in male otters.
C)   predation by killer whales.
D)   an increase in the water temperature.
E)   predation by Steller sea lions.F) D) and E)
G) B) and D)

Question 6

Parasitism is a symbiotic relationship in which neither member of the relationship benefits.

Accepted Answer

A) True 
 B)False

Question 7

A food chain is a series of organisms that

Accepted Answer

A)   shares the same niche.
B)   exhibits mutualism with each other.
C)   shares the same energy source.
D)   succeeds one another as a climax community develops.
E)   successively eats one another.F) A) and B)
G) B) and C)

Question 8

Which of the following is not a type of symbiosis?

Accepted Answer

A)   predation
B)   mutualism
C)   None of the answer choices are correct.
D)   commensalism
E)   parasitismF) A) and D)
G) A) and E)

Question 9

The physical place where members of a population typically live is termed a

Accepted Answer

A)   symbiont.
B)   competitive zone.
C)   habitat.
D)   niche.
E)   community.F) C) and D)
G) A) and B)

Question 10

After developing a yeast infection in the urinary tract,and taking an antibiotic,the yeast infection declines in numbers of cells while the microbes that normally are present reestablish themselves.The reason for the decline of the yeast infection is explained by

Accepted Answer

A)   the competitive exclusion principle.
B)   predation.
C)   the co-inclusion principle.
D)   symbiosis.
E)   endosymbiosis.F) None of the above
G) A) and C)

Question 11

The total amount of energy trapped by the autotrophs of an ecosystem is called

Accepted Answer

A)   gross primary consumption.
B)   net primary productivity.
C)   net energy fixation.
D)   gross primary productivity.
E)   net primary consumption.F) A) and D)
G) A) and E)

Question 12

Your biology class takes a field trip near the campus,and you walk along a trail,starting on bare rock and gravel.You learn that the entire area was stripped clear of any life by quarrying that removed meters of soil and rock nearly a century ago.At first,where you are told the most recent quarrying took place,you can see lichens and mosses growing on larger rocks.Further on,you can see grasses and weeds.Further still,where the first quarrying activities ended decades earlier,you see shrubs and trees.After all the area had been cleared,and this gradient of biota have developed,this is an example of which ecological process?

Accepted Answer

A)   magnification
B)   completion
C)   climax
D)   conversion
E)   successionF) D) and E)
G) C) and D)

Question 13

An organism that can use energy and inorganic substances to produce all the organic material it requires is a(n)

Accepted Answer

A)   producer.
B)   heterotroph.
C)   heterotroph and producer.
D)   autotroph.
E)   autotroph and producer.F) A) and D)
G) B) and D) E

Question 14

Prior to 1972,a pesticide called DDT was used widely in the United States,but was found to pose risks to human health and wildlife.The concentration of the nonpolar pesticide DDT would have been highest in which of the following,when still in use?

Accepted Answer

A)   algae
B)   a seagull
C)   a minnow
D)   plankton
E)   a mosquito larvaF) A) and B)
G) A) and C)

Question 15

Mistletoe is a plant that grows in the branches of trees.Its roots penetrate the bark of the tree,allowing it to obtain water and nutrients.The tree is harmed,and can even die as a result of this interaction.This is an example of

Accepted Answer

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

Question 16

What was the purpose of repeatedly drying,freezing,and thawing some of the fungi?

Accepted Answer

A)   to kill the fungi
B)   to make the fungus more susceptible to the virus
C)   to remove the virus
D)   to prepare the fungi to infect the panic grass
E)   to prepare the fungi for growth at 65°CF) A) and E)
G) C) and E)

Question 17

A type of symbiosis in which both species benefit is

Accepted Answer

A)   commensalism.
B)   mutualism.
C)   intraspecific competition.
D)   parasitism.
E)   predation.F) A) and E)
G) B) and D) B

Question 18

The _____ cycle begins with the weathering of rock.

Accepted Answer

A)   nitrogen
B)   carbon
C)   phosphorus
D)   water
E)   energyF) A) and B)
G) A) and C)

Question 19

As an overall average,about _____ of the energy at one trophic level is available to the next-highest rank in the food chain.

Accepted Answer

A)   7%
B)   10%
C)   4%
D)   20%
E)   2%F) A) and C)
G) B) and D)

Question 20

A type of symbiosis in which one member of the relationship benefits with no effect on the other is

Accepted Answer

A)   mutualism.
B)   commensalism.
C)   parasitism.
D)   intraspecific competition.
E)   predation.F) A) and C)
G) B) and D)

Exam 38: Communities and Ecosystems

In _____,bacteria return nitrogen to the atmosphere by converting nitrates to N₂.

Correct Answer
verified
C

An example of a keystone species is a root-associated fungus that conifer trees need in order to survive and that supply food for rodents.

Correct Answer
verified

An ecosystem is defined as

Correct Answer
verified

Mycorrhizal fungi obtain food from plants in exchange for water and nutrients.This is an example of

Correct Answer
verified

The decline of the sea otter population in the Pacific Northwest has been attributed to

Correct Answer
verified

Parasitism is a symbiotic relationship in which neither member of the relationship benefits.

Correct Answer
verified

A food chain is a series of organisms that

Correct Answer
verified

Which of the following is not a type of symbiosis?

Correct Answer
verified

The physical place where members of a population typically live is termed a

Correct Answer
verified

After developing a yeast infection in the urinary tract,and taking an antibiotic,the yeast infection declines in numbers of cells while the microbes that normally are present reestablish themselves.The reason for the decline of the yeast infection is explained by

Correct Answer
verified

The total amount of energy trapped by the autotrophs of an ecosystem is called

Correct Answer
verified

Correct Answer
verified

An organism that can use energy and inorganic substances to produce all the organic material it requires is a(n)

Correct Answer
verified
E

Prior to 1972,a pesticide called DDT was used widely in the United States,but was found to pose risks to human health and wildlife.The concentration of the nonpolar pesticide DDT would have been highest in which of the following,when still in use?

Correct Answer
verified

Mistletoe is a plant that grows in the branches of trees.Its roots penetrate the bark of the tree,allowing it to obtain water and nutrients.The tree is harmed,and can even die as a result of this interaction.This is an example of

Correct Answer
verified

What was the purpose of repeatedly drying,freezing,and thawing some of the fungi?

Correct Answer
verified

A type of symbiosis in which both species benefit is

Correct Answer
verified
B

The _____ cycle begins with the weathering of rock.

Correct Answer
verified

As an overall average,about _____ of the energy at one trophic level is available to the next-highest rank in the food chain.

Correct Answer
verified

A type of symbiosis in which one member of the relationship benefits with no effect on the other is

Correct Answer
verified

Exam 38: Communities and Ecosystems

In _____,bacteria return nitrogen to the atmosphere by converting nitrates to N2.

Correct AnswerverifiedC

An example of a keystone species is a root-associated fungus that conifer trees need in order to survive and that supply food for rodents.

Correct AnswerverifiedShow Answer

An ecosystem is defined as

Correct AnswerverifiedShow Answer

Mycorrhizal fungi obtain food from plants in exchange for water and nutrients.This is an example of

Correct AnswerverifiedShow Answer

The decline of the sea otter population in the Pacific Northwest has been attributed to

Correct AnswerverifiedShow Answer

Parasitism is a symbiotic relationship in which neither member of the relationship benefits.

Correct AnswerverifiedShow Answer

A food chain is a series of organisms that

Correct AnswerverifiedShow Answer

Which of the following is not a type of symbiosis?

Correct AnswerverifiedShow Answer

The physical place where members of a population typically live is termed a

Correct AnswerverifiedShow Answer

After developing a yeast infection in the urinary tract,and taking an antibiotic,the yeast infection declines in numbers of cells while the microbes that normally are present reestablish themselves.The reason for the decline of the yeast infection is explained by

Correct AnswerverifiedShow Answer

The total amount of energy trapped by the autotrophs of an ecosystem is called

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

An organism that can use energy and inorganic substances to produce all the organic material it requires is a(n)

Correct AnswerverifiedE

Prior to 1972,a pesticide called DDT was used widely in the United States,but was found to pose risks to human health and wildlife.The concentration of the nonpolar pesticide DDT would have been highest in which of the following,when still in use?

Correct AnswerverifiedShow Answer

Mistletoe is a plant that grows in the branches of trees.Its roots penetrate the bark of the tree,allowing it to obtain water and nutrients.The tree is harmed,and can even die as a result of this interaction.This is an example of

Correct AnswerverifiedShow Answer

What was the purpose of repeatedly drying,freezing,and thawing some of the fungi?

Correct AnswerverifiedShow Answer

A type of symbiosis in which both species benefit is

Correct AnswerverifiedB

The _____ cycle begins with the weathering of rock.

Correct AnswerverifiedShow Answer

As an overall average,about _____ of the energy at one trophic level is available to the next-highest rank in the food chain.

Correct AnswerverifiedShow Answer

A type of symbiosis in which one member of the relationship benefits with no effect on the other is

Correct AnswerverifiedShow Answer

In _____,bacteria return nitrogen to the atmosphere by converting nitrates to N₂.

Correct Answer
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C

Correct Answer
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E

Correct Answer
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B

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