RNA contains the nitrogenous base Uracil (B) instead of thymine which is found in DNA. RNA also contains ribose (D). This is the main difference between RNA and DNA. RNA is one of three biological molecules that is found in every cell in all forms of life. DNA and Proteins are the other two biological molecules. DNA and RNA carry the genetic material that allows organisms and cells to divide and multiply. Proteins are the hard workers of the cell.