APES Unit 1

In a given ecosystem, producers convert solar energy into of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers?

150 kcal

Algae in an aquatic food chain convert solar energy into kilocalories of plant tissue. Which of the following values best represents the amount of energy available for primary consumers in the food chain?

9,300 kilocalories

Algae in an aquatic food chain convert solar energy into kilocalories of plant tissue. Which of the following values best represents the amount of energy available for secondary consumers in the food chain?

930 kilocalories

Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers?

A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.

The diagrams above show an area that was once a pasture that has since undergone changes to the vegetation over time. Which of the following changes in the hydrologic cycle is most likely to occur as a result of the change in vegetation in the area?

A: Increased infiltration (Vegetation, such as trees and shrubs, increases infiltration by increasing the time of water penetration in the soil.)

Which letter correctly identifies a process of the hydrologic cycle in which the phase of water is changed from a liquid to a gas?

B. Evaporation

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. Infiltration

Which of the following pathways indicate how nitrogen is added to the largest nitrogen reservoir?

Denitrifying bacteria and volcanic activity

The table above shows the balanced chemical equations that represent three processes that are part of the nitrogen cycle. Which of the following is exemplified by the equations above?

Each biogeochemical cycle demonstrates the conservation of matter.

Which of the following best describes the movement of energy in an ecosystem?

Energy is harnessed by producers, and available energy decreases with each trophic level transfer.

Scientists calculated the net primary productivity at two different forest sites. Both forests have the same gross primary productivity. Forest has a net primary productivity of , and forest has a net primary productivity of . Which of the following statements is best supported by the data?

Forest A producers have lower rates of cellular respiration than forest B producers.

Which of the following statements is true of aquatic biomes?

Freshwater biomes are a vital source of drinking water.

Which of the following best describes gross primary productivity in an ecosystem?

Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.

Which of the following best describes the net primary productivity of an ecosystem?

Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem.

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

Phosphorus and nitrogen are both required for plant growth.

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?

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

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

STEP 3: Nitrification is the production of nitrates and nitrites by various species of bacteria.

Which of the following is the best explanation for why there is such a small amount of phosphorus that moves into aquatic systems?

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

Where is the majority of fresh water found on Earth?

ice caps and glaciers

Which of the following biomes is best characterized as an area that forms the narrow band along the coast that experiences a range of environmental conditions (including daily changes in sunlight, temperature, and water) ?

intertidal zones

Based on the diagram, which of the following reservoirs contains the most phosphorus?

sediments