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Biology · MICROBES IN HUMAN WELFARE

हिन्दी

Which of the following micro-organisms act as free-living nitrogen fixers in the soil?

  1. Rhizobium
  2. Azospirillum and Azotobacter
  3. Glomus
  4. Anabaena and Nostoc

Correct answer · Option 2

Azospirillum and Azotobacter

Explanation

Azospirillum and Azotobacter are free-living bacteria in the soil that can fix atmospheric nitrogen, whereas Rhizobium forms symbiotic associations in legume root nodules.

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