Final answer:
Ammonification is the release of ammonium ion from decomposing organic compounds in the nitrogen cycle, and the statement that nitrification converts nitrates to nitrites is false.
Correct option is b) Bacteria convert ammonia into ammonium ions
Step-by-step explanation:
Ammonification is the process by which ammonium ion (NH4+) is released from decomposing organic compounds. This is a key part of the nitrogen cycle, which also includes other processes like nitrification, denitrification, and nitrogen fixation. Nitrification involves the conversion of ammonium ions to nitrites (NO2-) and then to nitrates (NO3-), not the other way around. Therefore, the statement that nitrification by bacteria converts nitrates to nitrites is false. Nitrogen fixation is the conversion of nitrogen gas (N2) into ammonia (NH3), which can then be used by plants. This is typically carried out by nitrogen-fixing bacteria found in the soil or associated with the root nodules of legumes. Conversely, denitrification by bacteria converts nitrates back to nitrogen gas, which is then released into the atmosphere.