Answer:
The two examples of Nitrogen cycle re s follows-
- About 78% of the earth's atmosphere is comprised of Nitrogen and these can be carried to the oceans due to rainfall as well as by the rivers and streams from a particular area that ultimately connects the sea. This Nitrogen then undergoes the process of Nitrogen fixation, that are carried out by the bacteria which are commonly known as the cyanobacteria. After the process of Nitrogen fixation, these Nitrogen are suitable now for the phytoplanktons to use.
- The process of nitrification occurs after the conversion of ammonia. As a result of this, the ammonia then transforms into nitrite and nitrate. Due to the continuous upwelling and mixing of these nitrogen with the ocean water vertically it then carries these nitrate upward towards the sea level and photoplankton can use up this nitrogen.
This is how Nitrogen maintains a cyclicity.