Marie Michelle Catule

May 6, 2004

ESL 91 D01B

Essay #2 Final Draft


                                                  The Discovery of DNA

       Genetics is the scientific study of how living things pass from generation to generation. Therefore, genetics has produced many important discoveries such as the structure and function of DNA. DNA is very important in the field of biology and genetics because it’s found in every cell in our bodies and all living things. DNA is very important in our lives because it identifies our blood types. There are two people named James Watson and Francis Crick who discovered DNA. This discovery has proven to be the key of biology and earned them a Nobel Prize for Physiology and Medicine.

    According to the website about DNA at DNA (deoxyribonucleic acid) is a double helix which contains all genetic information in the cell chromosomes, plants, and animals’ cell.  In DNA there are two strands twisted around each other. There are four bases of DNA with two different types. Purines are the first type of DNA which contains adenine (A) and guanine (G). Pyrimidines are the second type of DNA which consists of cytosine (C) and thymine (T). DNA is an acid that carries information to the genetic cell. DNA is very important because it’s located in the nucleus cell for all living things. Forensic scientists have been able to go further in the studies due to the existence of DNA. Forensic scientists can now find the evidence to prove a case through not only blood, but, through nails, hair, saliva, skin, and anything in which they can find DNA. Scientists believe that the DNA double helix is one of the greatest discoveries in science because DNA describes how nature works.


    According to the text DNA and Genetics, James Watson was an American geneticist, who was one of the most important researchers in the field of genetics. According to the website about James Watson at, he attended Horace Mann Grammar School for eight years and spent two years in the South Shore High School. He received a scholarship for the University of Chicago. In the summer of 1943, Watson entered a four year college.  In 1947, Watson received two degrees in Zoology. Watson was interested in bird-watching, and then he received a fellowship for graduate study in Zoology.  At the University of Chicago, he received his first bachelor’s degree in zoology.    At the University of Indiana Watson received his doctorate degree and became interested in genetics

Watson met Francis Crick, who was involved in archeology, in the Cavendish Laboratory in 1950.  In the lab, Watson and Crick were working together and they discovered that DNA consisted of two strands.  From 1953 to 1955, Watson went to the California Institute of Technology as a senior researcher in biology to collaborate with other researchers. In 1955-1956 Watson went back to Cavendish to continue working with Crick. In 1956, Watson was a member of the Harvard Biology Department first as an Assistant professor. In 1958, he was an Associate professor and became professor in 1961. His book on the discovery of DNA, titled “The Double Helix”, was published in 1968. 

Francis Crick was an English physicist. According to the website about Francis Crick at www.mnsuedu/emuseum he attended Grammar school in Northampton and then went to Mill high school in London. In 1937, Crick studied Physics at the University College in London and earned his bachelor’s degree in science. In 1937, he started researching for a PH.D but he was interrupted because of the war in 1939. He worked as a scientist for the British Admiralty during the war. In 1947, he left the Admiralty to study biology. In 1947, Crick started working on his PH.D at the Strangeways Laboratory in Cambridge. He studied the physical properties of cytoplasm in the cultured fibroblast cells. At the Caius College Crick became a research student in 1950, and then he received his PH.D on x-ray diffraction “polypeptides and proteins”. Crick had done many other discoveries, but his best discovery was in the double helix of DNA. After he discovered the double helix, he wanted to find the relationship between DNA and genetic coding. Crick transferred to the Medical Research Unit at Cavendish Laboratory after two years. As soon he got to Cavendish he met Watson and started comparing their work according to the research that each of them had done. Crick brought his experiment on x-ray diffraction and Watson brought his experiment on phage and bacterial genetics.

      Watson and Crick were the two scientists who determined the structure of molecule DNA. During the experiment, they found that DNA’s shaped is like a double helix. They both believed that by solving the structure of DNA, it can lead to self-replication of genes. Watson and Crick worked together to understand what role DNA played in the replication of genes which obtained information from many different sources. For Crick and Watson the historic discovery was to investigate the role of DNA in the genes.    

      In conclusion, James Watson and Francis Crick developed a great example for others who want to pursue a career in biology to get an understanding of how DNA works and their examples help people to discover the importance of learning about DNA.  Their discovery has been acknowledged and won a Nobel Prize in 1962, which they shared with one another. DNA has opened the door for many scientists, with many more discoveries in the near future.