DNA
...e up of three units: a sugar molecule, a phosphate group, and one of four nitrogen based compouds, called bases. The bases are adenine (A), guanine (G), thymine (T), and cytosine (C). These are the "rungs" of the ladder. A always links to T, and G always links to C. When the cell multiplies into other cells, the DNA has to be "photocopied." This process of cell fragmentation is called mitosis. A special molecule called messenger ribonucleic acid, or mRNA is the photocopy of the original DNA and is transfered to the nucleus of the new cell by another type of molecule called transfer ribonucleic acid, or tRNA. You could think of tRNA as a person who takes the photocopy and puts it in a filecabinet. The two main scientists who discovered the double helix of DNA are James Watso and Francis Crick. They discovered it in February of 1953, and in 1962 they both were awarded the Nobel Prize for physiolgy or medicine for their work. James D. Watson was born in 1928 and is still alive today. He was a biochemist and Nobel Prize winner, who helped determine the structure of DNA today. He was born in Chicago, Illinois and went to co...