Distinguish between nitrogen fixation and nitrification. Name one bacterium capable of carrying out each of these processes.

Nitrogen fixation — The process of conversion of atmospheric nitrogen into nitrates is called Nitrogen fixation. Nitrogen fixation is done by bacteria present in root nodules of leguminous plants. For example, Rhizobium is found in root nodules of legumes and convert the atmospheric nitrogen into nitrates.

Nitrification — The process of conversion of ammonia into nitrates is called Nitrification. For example, Nitrosomonas converts ammonia into nitrates which is used by the plants.