Which biogeochemical cycle describes how nitrogen moves through an ecosystem?

• A. Phosphorus cycle
• B. Carbon cycle
• C. Nitrogen cycle
• D. Water cycle

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the concept of a biogeochemical cycle, which refers to the movement of chemical elements and compounds through living organisms, the atmosphere, water, and soil within an ecosystem.
2. Step 2: Recognize that the nitrogen cycle specifically describes how nitrogen moves through the ecosystem, including processes such as nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.
3. Step 3: Compare the nitrogen cycle to other biogeochemical cycles mentioned in the problem (e.g., phosphorus cycle, carbon cycle, water cycle) to understand their distinct roles in ecosystems. For example, the carbon cycle involves carbon dioxide and organic compounds, while the phosphorus cycle focuses on phosphorus movement, and the water cycle deals with water's physical states and movement.
4. Step 4: Identify key components of the nitrogen cycle, such as nitrogen-fixing bacteria, which convert atmospheric nitrogen (N₂) into ammonia (NH₃), and other processes that make nitrogen available to plants and animals.
5. Step 5: Conclude that the nitrogen cycle is the correct answer because it specifically addresses the movement of nitrogen through the ecosystem, unlike the other cycles listed.