ok, so here i think that i would be able to say that:
All nucleic acids are always made up of the same building blocks (monomers). Chemists and scientists call the monomers "nucleotides." The five pieces areuracil, cytosine, and thymine, and denine, and andguanine. No matter what science class you are in, you will always hear about ATCG when looking at the DNA.
hope that this helps.. =)