Question

10. What purpose does nitrogen fixation and assimilation serve in the biosphere?

Answer 1

Hi there,

Nitrogen circulates through atmosphere, lithosphere and hydrosphere, as elemental nitrogen i.e. N2 cannot be used by plants so it is fixed to ammonia and nitrates and nitrites by nitrogen fixation. Nitrogen fixing bacteria fix these nitrogen and live in symbiotic association with plants and thus provide nitrogen for plants to assimilate and use it for formation of nucleic acids and proteins. When organisms die, certain microbes such as detritivores decompose nitrogen into ammonia, making it available to be utilised by plants.

Hope this helps.