Which statement best describes how organisms use nitrogen? a) certain bacteria living in the roots of plants convert nitrogen to a form plants can use, and animals obtain their nitrogen by eating those plants. b) plants absorb nitrogen from the air in photosynthesis and add it to the sugars they produce. c) certain bacteria convert nitrogen to a form animals can use, and animals obtain their nitrogen by inhaling this nitrogen. d) animals absorb nitrogen from the air they breathe and incorporate it into their tissues.

a) Certain bacteria living in the roots of plants convert nitrogen to a form plants can use, and animals obtain their nitrogen by eating those plants.

Explanation:

Biological nitrogen fixation is a process by which soil bacteria traps the atmospheric nitrogen and convert it into organic compounds such as ammonia, nitrates and nitrites. These compounds are easily absorbed by the plant roots from soil. The plants use these forms of nitrogen to produce amino acids required for the synthesis of proteins and nucleic acids necessary for the plant growth.The animals eat these plants and obtain nitrogen so as to obtain energy and maintain the cellular metabolism. The nitrogen in the plant food facilitates the synthesis of amino acids in the animals necessary for production of proteins and nucleic acids.

On the basis of the above description, a) Certain bacteria living in the roots of plants convert nitrogen to a form plants can use, and animals obtain their nitrogen by eating those plants is the correct option.

biology is the study of life. it is the study of living organism.