The primary role of DNA in living organisms is to serve as the genetic material that carries instructions for growth, development, and reproduction. It encodes the information necessary to produce proteins, which perform various functions within the cell. DNA consists of sequences of nucleotides arranged in a double helix structure. These sequences are organized into genes, which determine heritable traits. Overall, DNA plays a crucial role in maintaining the integrity of genetic information and facilitating the inheritance of characteristics from one generation to the next.