Dna strand 303947

DNA Timeline

By antlk26

  • Oswald Avery

    Oswald Avery
    Oswald Avery showed that Fred Griffith’s “transforming principle” was DNA.

  • Erwin Chargaff

    Erwin Chargaff
    Erwin Chargaff isolated DNA from different organisms. He also measured the levels of each of the four nitrogenous bases and found that adenine and thymine are very close and that there is about the same amount of guanine and cytosine. Along with that, Chargaff found that Levenes tetranucleotide theory was incorrect.

  • Rosalind Franklin

    Rosalind Franklin
    Rosalind Franklin found that if you aim a stream of x-rays at a crystallized substance, some rays will be diffracted when they hit an atom, which can be recorded on photo film. The recorded photo is the “signature” of the molecule. She also discovered that the diffraction of the two fibers in DNA are different. Franklins information was then used to solve the 3D structure of DNA.

  • Hershey-Chase

    Hershey-Chase
    Alfred Hershey and Marsha chase did the blender experiment which proved phage DNA, not protein, was the genetic material.

  • James Watson and Francis Crick

    James Watson and Francis Crick
    James Watson and Francis Crick came up with the double helix structure for DNA.

  • Matthew Meselson

    Matthew Meselson
    Matthew Meselson worked on phage recombination and discovered that the enzymatic basis of host DNA protection recognizes its own DNA by adding methyl groups to it and that foreign DNA will be attacked and destroyed by restriction enzymes, but the host will still be intact. Meselson also discovered the process of DNA mismatch repair, which allows cells to fix mistakes in DNA.

  • Arthur Kornberg

    Arthur Kornberg
    Arthur Kornberg showed that life (DNA) can be made in a test tube by isolating DNA polymerase I.

  • Jacques Monod and Francois Jacob

    Jacques Monod and Francois Jacob
    Jacques Monod and Francois Jacob were the first to discover how genes were turned on and off.

  • Roy Britten

    Roy Britten
    Roy Britten showed that eukaryotic genomes have many repetitive, noncoding DNA sequences.

  • Mary-Claire King

    Mary-Claire King
    Mary-Claire King revolutionized the world of evolutionary biology with proof that chimpanzees and humans shared about 99% of their genetic material, which suggested that humans and chimps diverged from a common ancestor.