APES 6-8

Which of the following would best describe X in the diagram above?

A Bacteria play an important role in the conversion of compounds from the atmospheric gas to the form of the compound taken up by plants. B Phosphorus and nitrogen are both required for plant growth. C Volcanic eruptions are a major source of non-anthropogenic inputs. D Processes include weathering and erosion.

Directions: Select the choice that best fits each statement. The following question(s) refer to the following processes. (A) Nitrification (B) Denitrification (C) Assimilation (D) Ammonification (E) Nitrogen fixation Ammonia is converted to nitrite, then to nitrate.

A Nitrification

Select the choice that best fits each statement. The following question(s) refer to the following processes. (A) Nitrification (B) Denitrification (C) Assimilation (D) Ammonification (E) Nitrogen fixation Plant roots absorb ammonium ions and nitrate ions for use in making molecules such as DNA, amino acids, and proteins.

Assimilation

The two major processes involved in the carbon cycle are A weathering and erosion B photosynthesis and respiration C evaporation and transpiration D erosion and deposition E fixation and denitrification

B photosynthesis and respiration

Which of the following best helps to explain why phosphorus is often a limiting factor in many ecosystems?

Under many conditions, phosphorus forms stable insoluble compounds.

(A) Photosynthesis (B) Eutrophication (C) Denitrification (D) Decomposition (E) Transpiration The process by which a soil nutrient is reduced and released to the atmosphere as a gas

denitrification

Which of the following is an example of a carbon sink? A Deposition of organic matter on the deep ocean floor B Clearing of trees in the Amazon forest C Combustion of fossil fuels in power plants D Decomposition of food waste by bacteria E Nutrient uptake by the roots of grasses in a suburban lawn

deposition of organic matter on the deep ocean floor

Based on the data in the table, which of the following pairs of organisms has two ecological relationships, both competition and predation?

hawks and snakes

Which of the following elements is most likely to limit primary production in freshwater lakes? A Oxygen B Calcium C Phosphorus D Carbon E Iron

phosphorus

In the nitrogen cycle illustrated above, nitrification occurs in which of the following steps?

step 3

The process in the hydrologic cycle in which water vapor is released from leaves into the atmosphere is called A infiltration B transpiration C sublimation D reflection E percolation

transpiration

Approximately what percent of the water on Earth is freshwater (liquid and solid)? A 75% B 25% C 2.5% D 0.25% E 0.025%

C 2.5%

A field is abandoned, and an invasive plant that can live in nutrient-poor soil moves into the field. If the land is later cleared of this invasive species and it is discovered that the soil has an abundance of nitrogen compounds, what conclusion can best be made? A The plants used up all of the phosphorus and potassium and left the nitrogen behind. B Primary succession always produces an abundance of nitrogen. C Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds. D The plants were able to produce nitrogen in their leaves. E More rock was weathered and broken down to release nitrogen compounds.

C Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds.

Which of the following is true of carbon as it cycles in nature? A Carbon dioxide is released during photosynthesis. B Carbon compounds rarely exist in the gaseous state. C Carbon sinks include forests and oceans. D The carbon dioxide concentration in the atmosphere is reduced by cutting trees. E Carbon is concentrated in igneous rocks.

C Carbon sinks include forests and oceans.

How does the burning of fossil fuels contribute to the net increase in atmospheric carbon? A Photosynthesis is reduced by virtue of increased smoke and haze. B Carbon released by the burning is not in a form that can be readily absorbed by plants, leaving residual carbon in the atmosphere. C Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere. D Carbon released by the burning is more easily absorbed in the atmosphere than that produced by natural means. E Carbon released by the burning increases plant growth, producing more carbon for the atmosphere.

C Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere.

Which of the following pathways indicate how nitrogen is added to the largest nitrogen reservoir? A Nitrifying bacteria and lightning B Decomposing plant and animal material C Denitrifying bacteria and volcanic activity D Nitrates taken up by plant roots

C Denitrifying bacteria and volcanic activity

Which letter correctly identifies the part of the hydrologic cycle that is most directly affected by impervious building materials, such as concrete and asphalt?

D

According to the diagram, the movement of phosphorus between biological organisms and soil is in a steady state in an undisturbed system. Which of the following best explains the reason for this steady movement?

D Readily available organic phosphorus in the soil is assimilated by plants.

Based on the diagram above, which process most directly results in the storage of carbon as coal and oil over millions of years? A Photosynthesis B Cellular respiration C Decomposition D Burning of fossil fuels

Decomposition

Directions: Select the choice that best fits each statement. The following question(s) refer to the following processes. (A) Nitrification (B) Denitrification (C) Assimilation (D) Ammonification (E) Nitrogen fixation Nitrate ions and nitrite ions are converted into nitrous oxide gas and nitrogen gas (N2).

Denitrification

Photosynthesis is the major source of which of the following gases in Earth's atmosphere?

O2

Which of the following most directly explains the periodic fluctuations of the curve?

Seasonal variations in photosynthetic activity

Which of the following is a limitation of using only the data in the table to complete an ecological footprint analysis of the different students? A The footprint for each individual is based on simple calculations to determine approximate resource use. B The footprint uses a top-down approach to provide a complete picture of resource use for comparison between individuals. C The footprint uses global hectares, rather than hectares, to determine the approximate proportion of Earth's surface needed to support the activities of an individual. D The footprint is a static analysis and does not include all environmental impacts of an individual.

The footprint is a static analysis and does not include all environmental impacts of an individual.

Which of the following should be included in a watershed map to best determine the non-point source of a pollutant, such as fertilizer, found in a river? A The total volume of groundwater in the aquifer B The total area and the average yearly precipitation of the watershed C The land use upstream of the river and water quality indicators in streams that run downstream into the river D The total volume of surface water of the river and the land use downstream of the riverThe land use upstream of the river and water quality indicators in streams that run downstream into the river

The land use upstream of the river and water quality indicators in streams that run downstream into the river

Which of the following is the best explanation for why there is such a small amount of phosphorus that moves into aquatic systems? A Phosphorus is highly stable in the atmosphere and remains there for long periods of time. B The amount of phosphorus in the cycle has been greatly reduced because of the use of catalytic converters in automobiles. C There is not a gaseous phase of the phosphorus cycle, and therefore the movement of phosphorus into oceanic reservoirs is very slow. D The phosphorus cycle occurs so rapidly that it does not exist in any one reservoir for a very long time.

There is not a gaseous phase of the phosphorus cycle, and therefore the movement of phosphorus into oceanic reservoirs is very slow.