Question

which of the following is responsible for making nitrogen in the atmoshpere usable by living organisms?
A) Absorption of nitrogen rain
B) Conversion of nitrogen into carbohydrates by photosynthesis
C) Nitrogen-fixing bacteria
D) Decomposing bacteria

Answer 1

Answer:

A

Explanation:

It is absorption of nitrogen by rain. Thunderstorms and lightning convert atmospheric gaseous nitrogen to oxides of nitrogen. These oxides dissolve in water and form nitrous acid and nitric acid. The acid in turn combine with other salt to form "nitrates".

Note: Organisms cannot pickup gaseous nitrogen directly from atmosphere. It has to be converted into nitrates to be utilised.