APES Mid-term Review

In a given ecosystem, producers convert solar energy into 15,000kcal15,000kcal of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers?

1,50kcal

Algae in an aquatic food chain convert solar energy into 93,00093,000 kilocalories of plant tissue. Which of the following values best represents the amount of energy available for secondary consumers in the food chain?

9,300 kilcalories

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?

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

How does the burning of fossil fuels contribute to the net increase in atmospheric carbon?

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?

Denitrifying bacteria and volcanic activity

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.

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 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

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.

An energy transformation occurs and results in increased disorder.

Second law of thermodynamics

Of the following ecosystems, which has the lowest net primary productivity, measured as kilocalories of energy produced per square meter per year?

Temperature grassland

Losses of usable energy between successive trophic levels in an ecosystem are best accounted for by which of the following?

The second law of thermodynamics

Marine sediments that form limestone are a major sink for this element.

carbon

Open oceans produce the largest share of Earth's biomass because the net primary productivity (NPP) of the oceans is

low, but the large expanse of the oceans supports enormous numbers of producers such as phytoplankton

Ammonia is converted to nitrite, then to nitrate.

nitrification

Which of the following terrestrial biomes has the highest net primary productivity?

tropical rain forest