Chapter 23

Which of the following is not constantly recycled in the biosphere? a. energy b. water c. carbon d. nitrogen

Secondary succession is most likely to be found a. on rocky outcroppings. b. in areas that were clear-cut for timber. c. where an island has appeared. d. in areas where estuaries have filled in to form land.

Eutrophication a. is caused by an overabundance in nutrients that leads to an increase in algae in aquatic environments. b. usually occurs in deserts. c. is a process in which nitrogen is fixed. d. is a necessary part of the nitrogen cycle.

What is the original source of almost all the energy in most ecosystems? a. carbon dioxide b. water c. carbohydrates d. sunlight

Animals that eat both producers and consumers are called a. autotrophs. b. herbivores. c. omnivores. d. primary consumers.

Biogeochemical cycles a. include only abiotic processes. b. include only processes conducted by living organisms. c. transfer energy from one trophic level to the next. d. none of the above

The nitrogen cycle is important and complex. Why is nitrogen important? a. It is essential to photosynthesis. b. It is poisonous. c. It is a component of proteins and nucleic acids. d. It is a greenhouse gas that causes climate warming.

. An animal that eats an herbivore is called a(n) ____________.