DNA (deoxyribonucleic acid) strands are long, double-helix molecules that contain the genetic blueprint for living organisms. They are composed of four nucleotide bases: adenine, thymine, cytosine, and guanine. These bases pair in a specific manner (A-T and C-G) to form the rungs of the DNA ladder, while the sugar-phosphate backbone forms the sides. DNA strands carry the instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses.
