Overview

"Cracking" the genetic code was one of the most exciting discoveries of the twentieth century. Although philosophers and early scientists had long pondered the nature of inheritance, it was not until 1953 that James Watson (1928- ) and Francis Crick (1916- ) announced that they had determined that the code for life resides in the molecular structure of deoxyribonucleic acid (DNA). This announcement began a frenzy of investigation that still continues today. One of the hottest topics in science at the end of the twentieth century is molecular biology.

Many scientists have added to the knowledge of the genetic code. In 1955 Mahlon B. Hoagland (1921- ) isolated transfer ribonucleic acid (tRNA) while Robert Holley (1922-1993) described the complete structure of tRNA in 1965. In 1956 George Palade (1912- ), working with the small structures (organelles) within the cytoplasm of the cell, discovered ribosomes, the protein factories of the...