The letters DNA stand for deoxyribonucleic acid, the cellular material that stores and transmits genetic information. The information contained in DNA directs the synthesis of countless proteins. These proteins provide the structural and functional foundations necessary for life.

DNA was discovered in 1869 by German scientist Johann Friedrich Miescher (1844- 1895). He called this newly discovered molecule nuclein, otherwise known as nucleic acid, because it was found in the nucleus of cells. (The nucleus is a structure inside plant and animal cells.) Just a few years previous to Miescher's discovery, an Austrian monk named Gregor Johann Mendel (1822-1884) had made his first reports concerning the laws of genetics. However, it wasn't until the middle of the twentieth century that the two discoveries were joined and DNA was definitively accepted as the basis for genetic inheritance.

By the late nineteenth century, most scientists accepted the idea that inheritable characteristics were somehow...