History & Discovery of DNA Major Events

I) Are genes made up of DNA or proteins? A) Mendel’s work brings about a new way of looking at inheritance.

II) Friedrich Miescher A)Using microscopes, saw that the material inside the nucleus is half protein & half something other than protein 1868

III) Frederick Griffith A)Used Strep. pneumoniae to push favor towards DNA being the genetic material of choice 1928

III) Frederick Griffith B) Transformation 1)The process during which bacteria are changed by absorbing genetic material from an outside source

IV) Oswald Avery, Maclyn McCarty, & Colin MacLeod A)Used DNA- destroying & protein- destroying enzymes to show DNA was the transforming agent in Griffith’s experiment 1944

V) Alfred Hershey & Marsha Chase A)Settled the DNA/protein debate by proving that DNA was the genetic material B) Used viruses, which are made of only protein and DNA, in their experiment 1952

VI) P.A. Levine A) DNA is made-up of 4 nitrogenous bases, a phosphate group, & deoxyribose sugar

VII) Erwin Chargaff A)Looked for patterns in the chemical composition of DNA B)Analyzed four chemicals found in DNA: Adenine, Cytosine, Guanine, & Thymine Early 1950’s

C) Chargaff’s Rule

VIII) Franklin & Wilkins A) Rosalind Franklin, who worked for Maurice Wilkins, was working with X-rays and their applications B) She took x-ray diffractions pictures of DNA molecules 1951

IX) James Watson & Francis Crick A)Using all of this previous information, Watson & Crick solved the mystery of DNA’s structure 1953

Nobel Prize winners (left to right), December 1962 Maurice Wilkins, Max Perutz, Francis Crick, John Steinbeck, James D Watson, John Kendrew

X) 1960’s-Reading the Genetic Code A)Scientist learn how DNA is read into RNA & how RNA is made into proteins within the body

XI) 1970’s-Recombinant DNA A)Recombinant DNA technologies involves the joining of DNA from different species, DNA cloning, & DNA sequencing

XII) 1980’s-Trangenic Animals A)In the early 1980s, scientists figured out how to add new genes to animals B)Possible uses include medicines & organ transplants

XIII) 1990’s-Human Genome Project A)The Human Genome Project is launched. This is an attempt to read the entire three billion A, T, G, & C letters in human DNA B) Animals are cloned, starting with Dolly the Sheep

XIV) 2000 & Beyond-Human Genome Project A)Work is being done to save endangered species. B)The ultimate goal is to sequence every organism on the planet. C)The Human Genome Project is likely to affect the course of science and medicine throughout the 21st century.