Genetic carriers are substances that contain genetic information and are responsible for the transmission of hereditary traits. The two most common genetic carriers are DNA and nucleic acids. DNA, or deoxyribonucleic acid, is a molecule composed of four nucleotide bases: adenine, thymine, guanine, and cytosine. Nucleic acids are large molecules composed of nucleotides, which are made up of a sugar, a phosphate group, and a nitrogenous base. Both DNA and nucleic acids are essential for the transmission of genetic information from one generation to the next.