Final answer:
The nitrogen cycle involves nitrogen-fixing bacteria converting atmospheric nitrogen to ammonia, nitrification transforming it into nitrates, plant assimilation, transfer through food web, decomposition back to ammonium, and denitrification releasing nitrogen back to the atmosphere.
Step-by-step explanation:
The nitrogen cycle is a crucial ecological process where nitrogen moves between the atmosphere, organisms, and soil. In the cycle, nitrogen-fixing bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which is further transformed into ammonium (NH₄+). This ammonium is converted to nitrites (NO₂-) and nitrates (NO₃-) during nitrification. Plants assimilate these nitrates and incorporate them into organic compounds such as proteins and DNA. When animals consume these plants, the nitrogen is transferred through the food web. Decomposers play a critical role by breaking down dead organic matter and waste, converting organic nitrogen back into ammonium. Finally, during denitrification, some bacteria convert nitrates back into gaseous nitrogen (N₂), completing the cycle by releasing it into the atmosphere.