2007-06-19 14:27:01 · 4 answers · asked by paritosh a 1 in Science & Mathematics ➔ Biology
cells in human body contain 65-90% water by mass which is the source of H and O.
Proteins r the building blocks that determine characteristics of a human. Proteins r organic compounds made up of amino acids. A its organic , it contains C and N because itis made up of amino acids.
2007-06-20 01:36:02 · answer #1 · answered by cherry 2 · 0⤊ 0⤋
Because they are organic molecules.
2, the air is made up of 73% nitrogen
3, plants produce oxygen(there are a lot of plants)
4, we breathe out COO.
2007-06-19 14:38:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Living organisms require DNA and RNA and those elements are all key ingredients of both those chemical chains.
2007-06-19 14:30:12 · answer #3 · answered by jxt299 7 · 0⤊ 0⤋
because we're carbon based life forms that interact with the air...
2007-06-19 14:29:17 · answer #4 · answered by Anonymous · 0⤊ 0⤋