Question 1

High soil nutrient content usually leads to slower decomposition,because soil organisms have less need for nutrients of organic origin.

Accepted Answer

A) True 
 B)False

Question 2

The "denitrification" reaction converts nitrate (NO3-)to nitrogen gas (N2)under aerobic conditions.

Accepted Answer

A) True 
 B)False

Question 3

A normal distribution is assumed for which of the following statistical tests?

Accepted Answer

A)   Student's t-test
B)   95% confidence intervals
C)   regression analysis
D)   All of the choices are correct.
E)   both Student's t-test and 95% confidence intervalsF) C) and D)
G) A) and B)

Question 4

Nitrogen export was greatest in streams draining watersheds from

Accepted Answer

A)   forested areas.
B)   agricultural areas.
C)   suburban areas.
D)   urban areas.
E)   Nitrogen export was similar in streams from forested, agricultural, suburban, and urban areas.F) C) and D)
G) B) and D)

Question 5

The rate of decomposition of leaf litter in woodlands can be strongly influenced by

Accepted Answer

A)   moisture.
B)   nitrogen content.
C)   leaf toughness.
D)   All of the choices are correct.
E)   None of the choices are correct.F) A) and B)
G) All of the above D

Question 6

"Nitrogen fixation" refers to the conversion of
Rev: 12_06_2013_QC_42091

Accepted Answer

A)   carbon compounds to nitrogen compounds.
B)   nitrogen gas (N2)  to ammonia (NH3) .
C)   ammonia (NH3)  to nitrogen gas (N2) .
D)   ammonium (NH4+)  to nitrate (NO3-) .
E)   ammonium (NH4+)  to nitrite (NO2-) .F) B) and E)
G) B) and C)

Question 7

In aquatic ecosystems,leaves with high lignin content decompose

Accepted Answer

A)   rapidly because lignin is a nutrient-rich compound.
B)   rapidly because lignin enhances colonization by decomposing fungi.
C)   slowly because lignin reduces colonization by decomposing fungi.
D)   slowly because lignin is a carbon-poor compound.
E)   slowly because lignin-containing leaves sink rapidly.F) A) and D)
G) A) and C)

Question 8

Likens and Bormann found that over 90% of the nutrients in the Hubbard Brook Experimental Forest were in the soil organic matter.

Accepted Answer

A) True 
 B)False

Question 9

The process of denitrification is

Accepted Answer

A)   energy-yielding and aerobic.
B)   energy-releasing and aerobic.
C)   energy-yielding and anaerobic.
D)   energy-releasing and anaerobic.
E)   energy-neutral and anaerobic.F) None of the above
G) All of the above

Question 10

Streams with higher densities of stream invertebrates would be expected to have shorter spiraling lengths.

Accepted Answer

A) True 
 B)False

Question 11

The largest reservoir of phosphorus in most ecosystems is phosphorus

Accepted Answer

A)   in the atmosphere.
B)   dissolved in water.
C)   in rocks and sediments.
D)   bound in animal tissues.
E)   bound in plant tissues.F) B) and E)
G) B) and D) C

Question 12

The major pool of nitrogen in the atmosphere is the direct source of nitrogen for most organisms.

Accepted Answer

A) True 
 B)False

Question 13

The release of ammonium (NH4+)from decaying organic material is called ____________.

Accepted Answer

Question 14

A major perturbation of the carbon cycle by human activity is associated with

Accepted Answer

A)   release of carbon from carbonate rocks.
B)   release of carbon from fossil fuel deposits.
C)   removal of carbon from the atmosphere in the industrial production of fertilizers.
D)   accelerated removal of carbon from the atmosphere by forests.
E)   respiratory production of CO2 by the large human population.F) A) and B)
G) A) and C)

Question 15

Nitrate is converted to molecular nitrogen,N2,in a process called

Accepted Answer

A)   nitrogen fixation.
B)   ammonification.
C)   denitrification.
D)   nitrification.
E)   nitrogen assimilation.F) B) and D)
G) A) and E)

Question 16

Clearcutting at Hubbard Brook Experimental Forest sharply

Accepted Answer

A)   increased export of nitrate (NO3-)  in stream water.
B)   decreased export of nitrate (NO3-)  in stream water.
C)   increased rates of denitrification in soils.
D)   decreased deposition of ammonia (NH3)  from the atmosphere.
E)   increased deposition of ammonia (NH3)  from the atmosphere.F) B) and E)
G) A) and B)

Question 17

Phosphorus is an important constituent of

Accepted Answer

A)   DNA.
B)   bone tissue.
C)   RNA.
D)   ATP.
E)   All of the choices are correct.F) A) and D)
G) B) and C) E

Question 18

Nitrogen fixation is an energy-demanding process because of the strong _____ bond between the two nitrogen atoms in the N2 molecule.

Accepted Answer

A)   single covalent
B)   double covalent
C)   triple covalent
D)   ionic
E)   hydrogenF) A) and B)
G) B) and C)

Question 19

Nitrogen enrichment of ecosystems by human activity is largely driven by

Accepted Answer

A)   addition of nitrogen fertilizers.
B)   nitrogen pollution from burning of fossil fuels.
C)   nitrogen fixation by bacteria in landfills.
D)   Both addition of nitrogen fertilizers and nitrogen pollution from burning of fossil fuels.
E)   Both addition of nitrogen fertilizers and nitrogen fixation by bacteria in landfills.F) A) and B)
G) B) and C)

Question 20

________________ is the process of increased nutrient inputs into an ecosystem resulting in increased primary productivity and reduced biodiversity.

Accepted Answer

The answer of ________________ is the process of increased nutrient...

Exam 19: Nutrient Cycling and Retention

High soil nutrient content usually leads to slower decomposition,because soil organisms have less need for nutrients of organic origin.

Correct AnswerverifiedShow Answer

The "denitrification" reaction converts nitrate (NO3-)to nitrogen gas (N2)under aerobic conditions.

Correct AnswerverifiedShow Answer

A normal distribution is assumed for which of the following statistical tests?

Correct AnswerverifiedShow Answer

Nitrogen export was greatest in streams draining watersheds from

Correct AnswerverifiedShow Answer

The rate of decomposition of leaf litter in woodlands can be strongly influenced by

Correct AnswerverifiedD

"Nitrogen fixation" refers to the conversion of Rev: 12_06_2013_QC_42091

Correct AnswerverifiedShow Answer

In aquatic ecosystems,leaves with high lignin content decompose

Correct AnswerverifiedShow Answer

Likens and Bormann found that over 90% of the nutrients in the Hubbard Brook Experimental Forest were in the soil organic matter.

Correct AnswerverifiedShow Answer

The process of denitrification is

Correct AnswerverifiedShow Answer

Streams with higher densities of stream invertebrates would be expected to have shorter spiraling lengths.

Correct AnswerverifiedShow Answer

The largest reservoir of phosphorus in most ecosystems is phosphorus

Correct AnswerverifiedC

The major pool of nitrogen in the atmosphere is the direct source of nitrogen for most organisms.

Correct AnswerverifiedShow Answer

The release of ammonium (NH4+)from decaying organic material is called ____________.

Correct AnswerverifiedShow Answer

A major perturbation of the carbon cycle by human activity is associated with

Correct AnswerverifiedShow Answer

Nitrate is converted to molecular nitrogen,N2,in a process called

Correct AnswerverifiedShow Answer

Clearcutting at Hubbard Brook Experimental Forest sharply

Correct AnswerverifiedShow Answer

Phosphorus is an important constituent of

Correct AnswerverifiedE

Nitrogen fixation is an energy-demanding process because of the strong _____ bond between the two nitrogen atoms in the N2 molecule.

Correct AnswerverifiedShow Answer

Nitrogen enrichment of ecosystems by human activity is largely driven by

Correct AnswerverifiedShow Answer

________________ is the process of increased nutrient inputs into an ecosystem resulting in increased primary productivity and reduced biodiversity.

Correct AnswerverifiedShow Answer

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The "denitrification" reaction converts nitrate (NO₃^-)to nitrogen gas (N₂)under aerobic conditions.

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D

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C

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The release of ammonium (NH₄⁺)from decaying organic material is called ____________.

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Nitrate is converted to molecular nitrogen,N₂,in a process called

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E

Nitrogen fixation is an energy-demanding process because of the strong _____ bond between the two nitrogen atoms in the N₂ molecule.

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