ScienceClass 9CBSE
Q
The nitrogen molecules present in air can be converted into nitrates and nitrites by (a) a biological process of nitrogen fixing bacteria present in soil (b) a biological process of carbon fixing factor present in soil (c) any of the industries manufacturing nitrogenous compounds the plants used as cereal crops in field
A
Answer is (a) a biological process of nitrogen fixing bacteria present in soil
Explanation:
Cereal plants cannot fix the nitrogen on their own. They comprise of bacteria in their root nodules which will convert nitrates to nitrites. This process is called as nitrogen fixation.