Q. Which of the following elements play important role in Biological Nitrogen Fixation?
  1. Iron 
  2. Molybdenum 
  3. Magnesium 
Select the correct option from the codes given below:

Answer: Only 1 & 2
Notes: Only Iron and Molybdenum play important role in BNF. The enzyme used is called nitrogenase. The nitrogenase enzyme has two kinds of proteins viz. Iron Protein, and Iron-Molybdenum protein.