Review of the Nutrient Cycles
1) Why is it useful to study the cycling of matter in the biosphere?
2) Name the 4 main locations where carbon can found in the environment.
3) Where do all heterotrophs get their carbon and nitrogen from?
4) How does carbon in the air get into the bodies of living things? Name this process and
provide a word equation for it.
5) How does carbon get released into the atmosphere?
6) How does nitrogen get released into the atmosphere?
7) Why are carbon dioxide levels in the atmosphere higher today than perhaps ever before in
the earth’s known history?
8) The atmosphere consists of about 78% nitrogen. Why then is it often said that nitrogen is
a limiting factor in many terrestrial ecosystems?
9) What is meant by the term “nitrogen fixation”?
10) What is the difference between nitrogen fixing bacteria and denitrifying bacteria?
11) What role do decomposers play in the cycling of carbon and nitrogen?
12) We talked about nitrogen in 3 different forms: ammonia (NH4), nitrate (NO3) and gaseous
nitrogen (N2). Explain where each of these fits into the nitrogen cycle and how they relate
to each other.
13) a) What are the main consequences of burning fossil fuels?
b) What are some of the most important solutions to reducing fossil fuel usage while
continuing to meet our energy needs?
14) a) What are the main consequences of using artificial fertilizers?
b) What are some of the most important way to reduce the use of artificial fertilizer while
maintaining soil health?