The word Gattaca derived from the 4 DNA nitrogen bases: G(Guanine) A(Andenine) T(Thymine) and C(Cytosine)
the n-containing bases of DNA are Adenine, Thymine, Guanine and Cytosine. These bases are complementary in the following arrangements: A-T Adenine and Thymine C-G Cytosine and Guanine