both DNA and RNA are polymers composed of subunits known as
Making the world better, one answer at a time. DNA and RNA are polymers. Collectively, DNA and RNA are called nucleic acids. The subunits of nucleic acids are called nucleotides. Nucleotide monomers form nucleic acid polymers.A nucleotide has 3 parts to it: a phosphate group, a sugar (ribose in RNA and deoxyribose in DNA), and a base (Adenine, Guanine, Cytosine, Thymine or Uracil-Thymine is found only in DNA and Uracil is found only in RNA, but the other 3 bases may be found in either.).NA is built of billions of subunits called nucleotides.  Nucleotides are organic compounds that are made up of a nitrogenous  base, a sugar, and a phosphate group.