DNA

By cassianne

  • Miescher

    Miescher
    Friedrich Miescher was the first person to identify DNA as a distinct molecule. He isolated DNA and proteins from the cell nucleus. This helps scientists now by initially proving that DNA exists as its own molecule.

  • Chargaff

    Chargaff
    Erwin Chargaff made three rules that DNA always followed. The first rule was that the number of adenine always would equal the number of thymine. The second rules stated that the number of guanine would always equal the number of cytosine. The third rule stated that the number of purines would always equal the number of pyrimidines. This helps scientists today by giving them crucial information about the basepairs inside the DNA.

  • Hershey & Chase

    Hershey & Chase
    Hershey and Chase discovered that the DNA is the active component of the bacteriophage that transmits the infective characteristic, and that there was a relationship between DNA and genetic information. This helped scientists by showing them the relationship between DNA and bacteria.

  • Watson & Crick

    Watson & Crick
    James Watson and Francis Crick found out that DNA had a double-helix structure by making a 3D model with all of the things that they could find inside the lab. They compared their model to X-ray diffraction data to make their model even more efficient. This helped scientists now because they use the structure of the sugar and phosphate backbone zipped together by basepairs when studying DNA.

  • Franklin

    Franklin
    Rosalind Franklin made X-ray images of DNA to use it to help her figure out the structure of DNA. One of her pictures, picture 51, was used by other scientist to make their models of the DNA. Her picture helped prove the double-helix shape of the DNA that we use today.

  • Meselson & Stahl

    Meselson & Stahl
    Meselson & Stahl demonstrated that DNA stayed semi-conservative when duplicating, which means that the DNA contained only one strand of new DNA. They first discovered this through E.coli, but they also discovered that this happens in all organisms.

  • Bibliography - Part 1

    Works Cited
    "Crick Writes His 12-year-old Son About DNA Model." The History Blog. N.p., 11 May 2013. Web. 21 Jan. 2017.
    "Friedrich Miescher (1844-1895)." DNA from the Beginning. N.p., n.d. Web. 21 Jan. 2017.
    The Hershey-Chase Experiment. Digital image. Topics in the History of Genetics and Molecular Biology. N.p., 2000. Web. 21 Jan. 2017.
    "The Hershey-Chase Experiment." Topics in the History of Genetics and Molecular Biology. N.p., 2000. Web. 21 Jan. 2017.

  • Bibliography - Part 2

    Lents, Nathan H. Semi-Conservative Model of DNA. Digital image. Visionlearning. N.p., 2011. Web. 21 Jan. 2017.
    "Matthew Stanley Meselson (1930-)." DNA from the Beginning. N.p., n.d. Web. 21 Jan. 2017.
    Mccarthy, Eugene M. "Erwin Chargaff." Macroevolution. N.p., n.d. Web. 21 Jan. 2017.
    "Mode of DNA Replication: Meselson-Stahl Experiment." Khan Academy. N.p., n.d. Web. 21 Jan. 2017.
    Murray, Larry. Photograph 51. Digital image. Berkshire on Stage and Screen. N.p., 2 May 2016. Web. 21 Jan. 2017.

  • Bibliography - Part 3

    "Rosalind Franklin." DK Find Out! N.p., n.d. Web. 21 Jan. 2017.
    "Rosalind Franklin." Famous Scientists. N.p., 12 Aug. 2016. Web. 21 Jan. 2017.
    Watson and Crick's 3D Model of DNA. Digital image. The History Blog. N.p., 11 May 2013. Web. 21 Jan. 2017.