DNA, an abbreviation for deoxyribonucleic acid, is a molecule that provides the genetic instructions for the growth, functioning, development, and reproduction of all known organisms and many viruses. It is a polymer composed of two polynucleotide chains that coil around each other to form a double helix.
Each strand of a DNA molecule is composed of a long chain of monomer nucleotides. Each nucleotide of DNA is composed of a deoxyribose sugar molecule, a phosphate group, and one of four nitrogenous bases: Adenine [A], Guanine[G], Cytosine [C], and Thymine[T].