Nitrogen cycle is one of the most important microorganisms-mediated chemical reactions in aquatic and soil environments. In this context consider the following statements :
- 1. Nitrogen fixation is the process of oxidising NH₃ to NO₃⁻.
- 2. Nitrification process causes reduction of NO₃ and NO₂⁻ to NO₂, followed by recycling of N₂ to the atmosphere.
- 3. Denitrification converts molecular N₂ into a fixed form as an organic nitrogen.
How many of the statements given above is/are correct ?
1
2
3
None
Answer is Right!
Answer is Wrong!
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UPSC Geoscientist – 2024
– Statement 2 is incorrect: The process described (reduction of NO₃⁻ and NO₂⁻ to NO₂, followed by recycling of N₂ to the atmosphere) is denitrification, which is the conversion of nitrates and nitrites back into nitrogen gas (N₂) under anaerobic conditions. Nitrification is the oxidation of ammonia compounds.
– Statement 3 is incorrect: Denitrification converts fixed nitrogen (like nitrates and nitrites) back into atmospheric molecular nitrogen (N₂). The process that converts molecular N₂ into a fixed form as organic nitrogen (via ammonia) is nitrogen fixation.