Question

Azotobacter and Bacillus polymyxa are examples of

• A. Decomposers
• B. Non-symbiotic nitrogen fixer
• C. Symbiotic nitrogen fixer
• D. Pathogenic bacteria

Answer 1

The correct option is B Non-symbiotic nitrogen fixer

The atmospheric nitrogen is not available to plants. There are some nitrogen-fixing bacteria which converts atmospheric nitrogen into ammonia which is readily available to plants. Symbiotic nitrogen-fixing bacteria like Rhizobium lives in symbiotic association with the leguminous plants. Non-symbiotic nitrogen fixer converts atmospheric nitrogen into nitrogen compounds independently. Examples include Azotobacter, Bacillus polymyxa.

Thus, the correct answer is 'Non-symbiotic nitrogen fixer.'