Question

Air contains 78% nitrogen, yet nitrogen in its gaseous form is almost entirely unusable to life forms. a) In which form do the plants use nitrogen? b) In nature which organism fixes nitrogen? c) Name the five steps involved in the nitrogen cycle.

Answer 1

Air contains 78% of nitrogen. Nitrogen is used up by plants in the form of nitrates and nitrites. Bacteria is the organism which fixes nitrogen in nature.
The five steps involved in the nitrogen cycle are :-
(1) Nitrogen fixation
(2) Nitrification
(3) Assimilation
(4) Ammonification
(5) Denitrification

hope this helps you.