Final answer:
Nitrogen-fixing bacteria, like Rhizobium, convert atmospheric nitrogen into ammonia, which is used by plants to make nucleic acids and other biomolecules. This symbiotic relationship between bacteria and legume plants is important for sustainable agriculture.
Step-by-step explanation:
Nitrogen-fixing bacteria, such as Rhizobium, live in the roots of legume plants like clover, alfalfa, and peas. These bacteria convert atmospheric nitrogen into ammonia, a compound that plants can use to make nucleic acids and other essential biomolecules. This symbiotic relationship benefits both the bacteria and the plants. Nitrogen fixation is an important process in the nitrogen cycle and plays a key role in sustainable agriculture.