DNA contains the genetic code for all the proteins in the body. It is made up of nucleotides containing phosphate, deoxyribose sugar, and one of four nitrogenous bases (adenine, thymine, guanine, cytosine). The bases bond together following specific base pairing rules to form the famous double helix shape. The sequence of these bases along the DNA determines traits like hair and eye color by coding for different proteins. RNA carries copies of the DNA code to cellular structures called ribosomes to produce proteins according to the code.