DNA, short for deoxyribonucleic acid, is the molecule that contains the genetic code of organisms. ... Part of an organism's DNA is "non-coding DNA" sequences. They do not code for protein sequences. Some noncoding DNA is transcribed into non-coding RNA molecules, such as transfer RNA, ribosomal RNA, and regulatory RNAs.DNA is composed of four nitrogen-containing nucleobases; A, T, G, and C, or Adenosine, Thymine, Guanine, and Cytosine. Each base pairs up with another base to form complimentary base pairs, and it is these pairs that form the basis of DNA, as well as a sugar- deoxyribose- and a phosphate group.Three major forms of DNA are double stranded and connected by interactions between complementary base pairs. These are terms A-form, B-form,and Z-form DNA