What is the function of $Pseudomonas$ and $Thiobacillus$ in the $N_2$ cycle?

Which of the following soil microorganisms breaks down plant and animal protein into ammonia?

Nitrifying bacteria are those which can convert

Which of the following diagrams correctly depicts the $N_{2}$-cycle?

The process of conversion of $2 NO_{3}^{-} \rightarrow 2 NO_{2}^{-} \rightarrow 2 NO \rightarrow N_{2}O \rightarrow N_{2}$ is called and is carried out by:

Select the correct pair: