Which process describes the transfer of nitrogen through different environmental stages?

The correct answer is the nitrogen cycle, which is the process that describes the movement of nitrogen through various stages in the environment. This cycle involves several key steps: nitrogen fixation, where atmospheric nitrogen (N2) is converted into ammonia (NH3) by certain bacteria; nitrification, where ammonia is transformed into nitrites (NO2-) and nitrates (NO3-) that plants can absorb; and denitrification, where nitrates are converted back into atmospheric nitrogen, completing the cycle.

Understanding the nitrogen cycle is crucial because nitrogen is an essential nutrient for all living organisms, serving as a component of amino acids, proteins, and nucleic acids. The role of various organisms, including bacteria and plants, in this cycle illustrates the interconnectedness of environmental systems. The other processes—photosynthesis, carbon cycle, and phosphorus cycle—focus on different elements and do not specifically address the movement and transformation of nitrogen through ecosystems.