10/4/63 - DNA
Fritz Goro

One of nature's deepest mysteries, the transmission of the genetic code, the chemical control system that governs heredity and hence all life on earth, was suddenly, in a series of epic studies being conducted over the past few years being deciphered as scientists traced the secret to a substance called DNA.   The four colors in this plastic model of DNA symbolize the four chemicals that transmit all genetic data:  red for adenine, green for thymine, blue for guanine and yellow for cytosine.  For all its potency and complexity, the DNA molecule was found to weigh a mere two ten-trillionths of an ounce in a fertilized human egg.
