Remember, DNA polymerase also reads that DNA template from the three to five end and it synthesizes that DNA molecule from the five to three in the same way that RNA polymerase does. Now, the difference between RNA polymerase and DNA polymerase is in RNA polymerase. Notice we do not need a primer sequence to actually initiate the process. So in DNA polymerase we said that DNA polymerase requires that primer sequence but RNA polymerase does not. Now, unlike DNA polymerase which has the endonuclease activity has the ability to essentially correct the mistakes it makes. RNA polymerase cannot correct the mistakes it makes.