IGCSE Biology / Ecosystems

The nitrogen cycle

Edexcel International GCSE Biology (4BI1), chapter 14: Ecosystems, specification point 4.11B. Part of the full course.

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The nitrogen cycle moves nitrogen between the air, soil and living things. Bacteria change nitrogen compounds into forms that plants can use, and return nitrogen to the atmosphere.

More lessons in Ecosystems

• Habitat, population, community, ecosystem
• Practical: quadrats and transects
• What biodiversity means and how it is measured
• Food chains and food webs
• Decomposers and decay
• Pyramids of number, biomass and energy
• Why energy is lost between levels
• The carbon cycle