The amount of nitrogen fixed electrochemically and photochemically is:

Match Column $- I$ with Column $- II.$

Column $- I$	Column $- II$
$(a)$ Nitrococcus	$(i)$ Denitrification
$(b)$ Rhizobium	$(ii)$ Conversion of ammonia to nitrite
$(c)$ Thiobacillus	$(iii)$ Conversion of nitrite to nitrate
$(d)$ Nitrobacter	$(iv)$ Conversion of atmospheric nitrogen to ammonia

Choose the correct answer from the options given below.

The process of conversion of nitrogen gas into ammonia is called $P$,and the process of decomposition of organic nitrogen in plants and animals into ammonia is called $Q$.

Fishing and Guano birds assist the cycling of

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

Conversion of $NH_{3} \rightarrow NO_{2}^{-} \rightarrow NO_{3}^{-}$ is called: