Which of following organisms cannot fix nitrogen?A. AzotobacterB. OscillatoriaC. AnabaenaD. VolvoxE. NostocChoose the correct answer from the options given below:

1. A only

2. D only

3. B only

4. E only

Doubtly Asked 30 Oct 2026 NEET UG 2025 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 2. D only

Key idea: Volvox is a green alga and cannot fix nitrogen.

Azotobacter (free-living bacterium) and Oscillatoria, Anabaena, Nostoc (cyanobacteria) fix atmospheric nitrogen. So D only.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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