Chapter 51

Which of the following events would move energy and material from a detrital food web into a grazing food web? a. A beetle eats the leaves of a living plant. b. An earthworm eats dead leaves on the forest floor. c. A robin catches and eats an earthworm. d. A crow eats a dead robin. e. A bacterium decomposes the feces of an earthworm.

The total dry weight of plant material in a forest is a measure of the forest's: a. gross primary productivity. b. net primary productivity. c. cellular respiration. d. standing crop biomass. e. ecological efficiency.

Which of the following ecosystems has the highest rate of net primary productivity? a. open ocean b. temperate deciduous forest c. tropical rain forest d. desert and thornwoods e. agricultural land

Endothermic animals exhibit a lower ecological efficiency than ectothermic animals because: a. endotherms are less successful hunters than ectotherms. b. endotherms eat more plant material than ectotherms. c. endotherms are larger than ectotherms. d. endotherms produce fewer offspring than ectotherms. e. endotherms use more of their energy to maintain body temperature than ectotherms.

The amount of energy available at the highest trophic level in an ecosystem is determined by: a. only the gross primary productivity of the ecosystem. b. only the net primary productivity of the ecosystem. c. the gross primary productivity and the standing crop biomass. d. the net primary productivity and the ecological efficiencies of herbivores. e. the net primary productivity and the ecological efficiencies at all lower trophic levels.

Some freshwater and marine ecosystems exhibit an inverted pyramid of: a. biomass. b. energy. c. numbers. d. turnover. e. ecological efficiency.

Which process moves nutrients from the available-organic compartment to the available-inorganic compartment? a. respiration b. erosion c. assimilation d. sedimentation e. photosynthesis

Which of the following materials has a sedimentary cycle? a. water b. oxygen c. nitrogen d. phosphorus e. carbon

Nitrogen fixation converts: a. atmospheric molecular nitrogen to ammonia. b. nitrates to nitrites. c. ammonia to molecular nitrogen. d. ammonia to nitrates. e. nitrites to nitrates.