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  • Khan Academy
    If you're seeing this message, it means we're having trouble loading external resources on our website If you're behind a web filter, please make sure that the domains * kastatic org and * kasandbox org are unblocked
  • The nitrogen cycle - Khan Academy
    Learn about the nitrogen cycle and how nitrogen moves from the atmosphere to living organisms through different chemical forms
  • The nitrogen cycle (apply) (practice) | Khan Academy
    Apply your understanding about the nitrogen cycle in this set of free, standards-aligned practice questions
  • 可汗学院 - Khan Academy
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  • The nitrogen cycle - Khan Academy
    Bacteria play a key role in the nitrogen cycle Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen— N 2 ‍ —into biologically usable forms in a process called nitrogen fixation
  • The nitrogen cycle (video) | Ecology | Khan Academy
    The nitrogen cycle is a crucial process that converts atmospheric nitrogen into a form that plants and other organisms can use This process, known as nitrogen fixation, is primarily carried out by bacteria Nitrogen is essential for life, forming a key component in amino acids, ATP, and DNA
  • Khan Academy
    Notre mission : apporter un enseignement gratuit et de qualité à tout le monde, partout Plus de 6 000 vidéos et des dizaines de milliers d'exercices interactifs sont disponibles du niveau primaire au niveau universitaire
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