Final answer:
The process by which mutualistic bacteria move nitrogen from the atmosphere to soil is called nitrogen fixation, a crucial step in the nitrogen cycle. Nitrogen-fixing bacteria convert atmospheric nitrogen into ammonia, differing from nitrification, ammonification, and denitrification, which are other steps of the cycle.
Step-by-step explanation:
The process (or set of processes) by which mutualistic bacteria move nitrogen from the atmosphere to soil is called nitrogen fixation. This is a part of the nitrogen cycle, where nitrogen-fixing bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which is then available for use by plants. Nitrogen fixation occurs in the root nodules of leguminous plants and by free-living soil bacteria.
In contrast, nitrification is the process by which ammonia (NH₃) is converted into nitrites (NO₂⁻) and then nitrates (NO₃⁻). This involves two steps and different types of bacteria. Ammonification, on the other hand, is the process by which organic nitrogen is converted into ammonia, while denitrification is the process where nitrates are converted back into nitrogen gas (N₂).
It's important to note that one of the statements provided is false. In nitrification, bacteria convert ammonia into nitrites and then to nitrates, not the other way around as stated incorrectly in one of the given statements.