Question 1

Describe the path of nitrogen as it moves from the atmosphere to the soil, plants, animals, and back to the atmosphere. Describe each process and the location and the form of nitrogen (including chemical formula) at each step.

Accepted Answer

The answer of Describe the path of nitrogen as it...

Question 2

In the Hubbard Brook Experimental Forest, researchers found a 90 percent reduction in nitrates leaving the watershed over a 5-year period. To what did they attribute the majority of this reduction?

Accepted Answer

A)  changes in species composition 
B)  recovery from past disturbances 
C)  increased soil pH 
D)  climate change

Question 3

Why is the phosphorus cycle described as less complicated than the nitrogen cycle?

Accepted Answer

The answer of Why is the phosphorus cycle described as...

Question 4

Which of the following is NOT a critical phosphorus-containing structure for organisms?

Accepted Answer

A)  bones 
B)  nucleic acids 
C)  ATP 
D)  lipids 
E)  teeth

Question 5

When terrestrial ecosystems are paved over, for example to construct a parking lot, how is the hydrologic cycle affected?

Accepted Answer

A)  Infiltration is decreased and runoff is increased. 
B)  Infiltration is increased and runoff is decreased. 
C)  Evapotranspiration is increased and runoff is decreased. 
D)  Evapotranspiration is increased and precipitation is decreased.

Question 6

Nitrogen fixation in the soil is carried out by

Accepted Answer

A)  anaerobic bacteria. 
B)  aerobic bacteria. 
C)  mycorrhizal fungi. 
D)  cyanobacteria. 
E)  archaebacteria.

Question 7

In the study of leaf decomposition in a stream in Germany using leaf litter enclosed in either fine- or large-mesh bags, researchers found that decomposition was strongly affected by

Accepted Answer

A)  invertebrates and lignin content. 
B)  vertebrates and lignin content. 
C)  nitrogen and phosphorus. 
D)  lignin and phosphorus.

Question 8

Current atmospheric carbon dioxide levels are approximately

Accepted Answer

A)  256 ppm. 
B)  410 ppm. 
C)  394 ppm. 
D)  385 ppm.

Question 9

Decomposition is more rapid in _____ forests because of _____.

Accepted Answer

A)  temperate; increased temperature and precipitation 
B)  temperate; increased pH and elevated potassium levels 
C)  tropical; increased temperature and precipitation 
D)  tropical; lower nutrient contents and low pH

Question 10

In aquatic ecosystems, most nutrients regenerate in

Accepted Answer

A)  surface waters. 
B)  algal biomass. 
C)  deep waters. 
D)  sediments.

Question 11

The chemical process NH4+ → NO2− → NO3−, is known as

Accepted Answer

A)  assimilation. 
B)  mineralization. 
C)  nitrification. 
D)  nitrogen fixation. 
E)  ammonification.

Question 12

Topic the breakdown of organic matter
Level: medium
Leaf litter with a _____ lignin composition should _____ k.

Accepted Answer

A)  high; increase 
B)  high; decrease 
C)  low; increase 
D)  low; decrease

Question 13

The leaf decomposition in a tropical forest

Accepted Answer

A)  increases with increasing leaf solubility. 
B)  decreases with increasing leaf solubility. 
C)  is unaffected by leaf solubility. 
D)  increases with soil pH.

Question 14

Weathering is important to the input of

Accepted Answer

A)  nitrogen. 
B)  carbon. 
C)  phosphorus. 
D)  water.

Question 15

Marine dead zones are formed when rivers that empty into oceans carry excess phosphorus and nitrate runoff. These dead zones are caused by

Accepted Answer

A)  precipitates of nitrate and phosphorus forming in the water. 
B)  bacterial blooms. 
C)  algal blooms. 
D)  nitrate and phosphorus poisoning. 
E)  increased acidity due to nitrates and phosphorus.

Question 16

The carbon cycle in ecosystems mostly follows the same paths as the movement of

Accepted Answer

A)  water. 
B)  nitrogen. 
C)  phosphorus. 
D)  energy. 
E)  heat.

Question 17

What are the six types of transformations in the carbon cycle?

Accepted Answer

A)  photosynthesis, respiration, combustion, infiltration, sedimentation, burial 
B)  combustion, precipitation, respiration, aeration, photosynthesis, exchange 
C)  respiration, aeration, condensation, photosynthesis, exchange, extraction 
D)  extraction, exchange, respiration, photosynthesis, sedimentation and burial, combustion 
E)  sedimentation and burial, photosynthesis, respiration, exchange, mineralization, combustion

Question 18

How does phosphorus lead to eutrophication of aquatic ecosystems?

Accepted Answer

The answer of How does phosphorus lead to eutrophication of...

Question 19

In waterlogged conditions, anaerobic metabolism of carbon compounds can cause the production of the greenhouse gas

Accepted Answer

A)  hydrogen sulphide (H2S). 
B)  methane (CH4). 
C)  ozone (O3). 
D)  nitrous oxide (N2O). 
E)  carbon dioxide (CO2).

Question 20

Where does phosphorus originate in the phosphorus cycle?

Accepted Answer

A)  the atmosphere 
B)  ocean sediments 
C)  wastewater 
D)  rocks containing phosphate 
E)  aqueous phosphate

Exam 21: Movement of Elements in Ecosystems

Describe the path of nitrogen as it moves from the atmosphere to the soil, plants, animals, and back to the atmosphere. Describe each process and the location and the form of nitrogen (including chemical formula) at each step.

In the Hubbard Brook Experimental Forest, researchers found a 90 percent reduction in nitrates leaving the watershed over a 5-year period. To what did they attribute the majority of this reduction?

Why is the phosphorus cycle described as less complicated than the nitrogen cycle?

Which of the following is NOT a critical phosphorus-containing structure for organisms?

When terrestrial ecosystems are paved over, for example to construct a parking lot, how is the hydrologic cycle affected?

Nitrogen fixation in the soil is carried out by

In the study of leaf decomposition in a stream in Germany using leaf litter enclosed in either fine- or large-mesh bags, researchers found that decomposition was strongly affected by

Current atmospheric carbon dioxide levels are approximately

Decomposition is more rapid in _ forests because of _.

In aquatic ecosystems, most nutrients regenerate in

The chemical process NH₄⁺ → NO₂⁻ → NO₃⁻, is known as

Topic the breakdown of organic matter Level: medium Leaf litter with a _ lignin composition should _ k.

The leaf decomposition in a tropical forest

Weathering is important to the input of

Marine dead zones are formed when rivers that empty into oceans carry excess phosphorus and nitrate runoff. These dead zones are caused by

The carbon cycle in ecosystems mostly follows the same paths as the movement of

What are the six types of transformations in the carbon cycle?

How does phosphorus lead to eutrophication of aquatic ecosystems?

In waterlogged conditions, anaerobic metabolism of carbon compounds can cause the production of the greenhouse gas

Where does phosphorus originate in the phosphorus cycle?

Exam 21: Movement of Elements in Ecosystems

Describe the path of nitrogen as it moves from the atmosphere to the soil, plants, animals, and back to the atmosphere. Describe each process and the location and the form of nitrogen (including chemical formula) at each step.

In the Hubbard Brook Experimental Forest, researchers found a 90 percent reduction in nitrates leaving the watershed over a 5-year period. To what did they attribute the majority of this reduction?

Why is the phosphorus cycle described as less complicated than the nitrogen cycle?

Which of the following is NOT a critical phosphorus-containing structure for organisms?

When terrestrial ecosystems are paved over, for example to construct a parking lot, how is the hydrologic cycle affected?

Nitrogen fixation in the soil is carried out by

In the study of leaf decomposition in a stream in Germany using leaf litter enclosed in either fine- or large-mesh bags, researchers found that decomposition was strongly affected by

Current atmospheric carbon dioxide levels are approximately

Decomposition is more rapid in _____ forests because of _____.

In aquatic ecosystems, most nutrients regenerate in

The chemical process NH4+ → NO2− → NO3−, is known as

Topic the breakdown of organic matter Level: medium Leaf litter with a _____ lignin composition should _____ k.

The leaf decomposition in a tropical forest

Weathering is important to the input of

Marine dead zones are formed when rivers that empty into oceans carry excess phosphorus and nitrate runoff. These dead zones are caused by

The carbon cycle in ecosystems mostly follows the same paths as the movement of

What are the six types of transformations in the carbon cycle?

How does phosphorus lead to eutrophication of aquatic ecosystems?

In waterlogged conditions, anaerobic metabolism of carbon compounds can cause the production of the greenhouse gas

Where does phosphorus originate in the phosphorus cycle?

Decomposition is more rapid in _ forests because of _.

The chemical process NH₄⁺ → NO₂⁻ → NO₃⁻, is known as

Topic the breakdown of organic matter Level: medium Leaf litter with a _ lignin composition should _ k.