Fill in the blanks in the table below summarizing terrestrial ­nutrient cycles.

Which of the following organisms is incorrectly paired with its trophic level?a. cyanobacterium—primary producerb. grasshopper—primary consumerc. zooplankton—primary producerd. fungus—detritivore

What is the main global reservoir of nitrogen?

Add labels to the figure that follows, which illustrates the interacting factors in a declining population that contribute to the extinction vortex.

Which of these ecosystems has the lowest net primary production per square meter?a. a salt marshb. an open oceanc. a coral reefd. a tropical rain forest

True or False: Most of the net primary productivity that is consumed is used for growth by primary consumers. Explain.

Which of the following is the longest-lived reservoir for carbon?a. atmospheric CO2b. marine plankton (primary producers and consumers)c. fossil fuelsd. wood

Nitrifying bacteria participate in the nitrogen cycle mainly bya. converting nitrogen gas to ammonia.b. releasing ammonium from organic compounds, thus returning it to the soil.c. converting ammonium to nitrate, which plants absorb.d. incorporating nitrogen into amino acids and organic compounds.

If you applied a fungicide to a cornfield, what would you expect to happen to the rate of decomposition and net ecosystem production (NEP)?a. Both decomposition rate and NEP would decrease.b. Neither would change.c. Decomposition rate would increase and NEP would decrease.d. Decomposition rate would decrease and NEP would increase.