Question

Micro-organisms responsible for nitrification are

• A. Nitrosomonas and Nitrobacter
• B. Nostoc and Anabaena
• C. Rhizobium and Azotobacter
• D. Clostridium and Pseudomonas

Hint:

Remember: Nitrification involves two steps – ammonia to nitrite (Nitrosomonas) and nitrite to nitrate (Nitrobacter).

Answer 1

The Correct Option is A

Step 1: Understanding nitrification.
Nitrification is the biological oxidation of ammonia (\( NH_3 \)) to nitrite (\( NO_2^- \)) and then to nitrate (\( NO_3^- \)).
Step 2: Micro-organisms involved.
- Nitrosomonas oxidizes ammonia into nitrite.
- Nitrobacter oxidizes nitrite into nitrate.
Thus, the micro-organisms responsible for nitrification are Nitrosomonas and Nitrobacter.
Final Answer: \[ \boxed{\text{Nitrosomonas and Nitrobacter}} \]