Answer:
very interesting question. it all has to do with DNA, which is a long strand of molecules. basically, only certain parts of the DNA, called genes, are used to in every cells. for instance, a bone cell will only use genes that allow it to build or break down bone
Explanation:
 
        
             
        
        
        
Understandable, have a great day
 
        
             
        
        
        
1.Nucleic acids:Stores and transfers info
2.Carbohydrates:Store energy, provide fuel, and build structure in body, main source of energy, structure of plant cell wall
3.Lipid:Insulator and stores fat and energy
4.Protein:Provide structural support, transport, enzymes, movement, defense
        
             
        
        
        
  the answer is 21<span>% oxygen, </span>