Question

Nitrogen is an essential element for living organism. The cycling of nitrogen through the ecosystem is complex. Further, not all forms of nitrogen are usable by living organism.

e) The process of converting nitrogen gas in the atmosphere to a form usable by plants and animals is called _____________________ .

Answer 1

Athmospheric nitrogen cannot be used by the plants. It must be transformed into usable form either by lighting or by the microoragnism.

Athmospheric nitrogen first transformed into nitrites and nitartes ions by the lighting or by microorganism.

In first stage nitrogen is transformed into ammonia and fixed in the soil. Then the microorganism transformed it into nitrites ion. This process is called the Nitrogen Fixation.

The nitrobacter then transformed the nitrites ion to nitrate which is absorbed by the plant roots. These nitrate ions then used by plants to produce various amino acid to form essential protein. This process is called Assimilation of nitrogen.

So the right answer is NITROGEN FIXATION. By this process the nitrogen is first transformed into the usable form.

In assimilation the usable form of nitrogen is absorbed by the plants.