Deoxyribonucleic acid (DNA) is a complex polymer composed of nucleotide subunits, typically organized into a double helical structure. This molecule contains the genetic blueprint for the development, function, growth, and reproduction of all known life forms. The unique linear sequence of its nitrogenous bases—adenine, thymine, guanine, and cytosine—determines the specific genetic code. This code acts as a mechanism for storing inherited information and is replicated with high fidelity, ensuring the accurate transmission of biological instructions during cell division. The structural integrity and biochemical properties of the molecule are central to biochemistry and molecular biology.