Which of these most accurately describes the role of certain bacteria living in and around plant roots in the soil? A) They aera
te the soil, providing necessary oxygen for the plant. B) They convert carbon dioxide into starch, a usable form for the plant. C) They accelerate weathering to allow ready access to phosphorous for the plant. D) They convert elemental nitrogen into ammonia and nitrates for uptake by the plants.
The correct answer is D) They convert elemental nitrogen into ammonia and nitrates for uptake by the plants.
Explanation:
Plants and crops are not able to use elemental nitrogen. Most of the microorganisms that live around the roots of the plant helps in converting the elemental nitrogen into ammonia and nitrate so that plants can use and uptake the nitrogen from soil.
These bacteria are called nitrogen-fixing bacteria. They invade the roots of plants and crops and form root nodules where they grow and convert nitrogen into ammonia and nitrate which is taken by plants. Some nitrogen-fixing bacteria are <em>Rhizobium , Nostoc, Azotobacter, Beijerinckia,</em> etc. So the right answer is D.
