AP Environmental Science - 1.5 The Nitrogen Cycle

Which is the main reservoir of nitrogen?

• The atmosphere

• The roots of legumes

• Plant and animal tissues

• Sedimentary rocks

Which of these converts nitrogen from the atmosphere into a form that is usable by plants?

• fixation

• assimilation

• denitrification

Which of these plays a significant role in the nitrogen cycle?

• bacteria

• viruses

• mammals

Describe one chemical transformation that occurs in the natural nitrogen cycle and explain the importance of that transformation to an ecosystem.