DNA polymerases is the enzyme that catalyzes DNA synthesis, but it is different from RNA polymerases. This particular type of polymerases have specific conditions and requirements that must be met for them to be produced. Without these enzymes, the nucleotides that are the building blocks of DNA cannot be made.
The enzymes work in pairs to create the two identical DNA strands needed to build the familiar double helix shape that the chromosomes have. The DNA polymerases being to add nucleotides to the 3' end of the DNA strand, which results in the elongation of the chain. There is no known way for these enzymes to begin a chain from nothing, but must add onto an existing 3'-OH group. This is why there has to be a primer in the steps so that the enzymes have something to start building on.
This is one of the many points where RNA can play a role in the reproduction of DNA by acting as a building primer for the DNA enzymes. Before any of this can occur, however, helicase must be created or brought into the nucleus to unzip the DNA strands so that they can be translated and then duplicated. If the DNA is not translated into a language the rest of the cell can understand, the replication process will not be possible.