Answer: DNANitrogen is a natural occurring element that is required by the living organisms such as plants and animals for growth and reproduction. It is an important ingredient of the genome of the living organisms. The DNA is a thread like structure which is produced inside the cells of the plants, animals and in some microbes. It is a hereditary material that is transmitted from generation to generation of the living organisms. Hence, it is importance for the existence of diversity of life forms on earth.
Well, nitrogen is the gas that makes up 78% of the earth's atmosphere.
I would guess its in the air that we breathe. I am not really sure. Just basing this answer off of research.