Answer:
Nitrogen is converted from atmospheric nitrogen (N2) into usable forms, such as NO2-, in a process known as fixation. ... This occurs in two steps: first, bacteria convert ammonia in to (nitrites) NO2-, and then other bacteria species convert it to NO3- (nitrate). Nitriates are a form of nitrogen that is usable by plants.
Explanation:
1859
On the Origin of Species (or more completely, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life), published on 24 November 1859, is a work of scientific literature by Charles Darwin which is considered to be the foundation of evolutionary biology.
Answer: scientific theory is an explanation of observations or events that is based on knowledge gained from many observations or events.