Genetic Timeline - DNA

By 14duker
  • Gregor Mendel

    Experiement - he test crossed pea plants
    Contribution - traits are inherited from parents
  • William Bateson and Reginald Punnett

    William Bateson and Reginald Punnett
    Experiment - tested 2 characteristics in pea plants; crossed double heterozygous plants
    Contribution - punnett squares; linked genes
  • Thomas Hunt Morgan

    Thomas Hunt Morgan
    Experiment - observing inheritance of traits in fruit flies
    Contribution - effects of crossing over
  • Archilbald Garrod

    Archilbald Garrod
    Experiment - observed inherited disease alkaptouria
    Contribution - genes dictate phenotypes through enzymes
  • Frederick Griffith

    Frederick Griffith
    Experiment - experimented with pathogenic and harmless bacteria; pathogenic killed, harmless had no effect, heated pathogenic and harmless mixed which killed.
    Contribution- discovered there must be a transforming factor
  • George Beadle and Edward Tatum

    Experiment - studied mold on surfaces; mold that couldn't grow on one surface lacked an enzyme, thus resulting in a defective gene.
    Contribution - genes dictated the production of enzymes
  • Erwin Chargaff

    Erwin Chargaff
    polynucleotide chains; A paired with T; C paired with G
    Contribution - Adedine amount = thymine amount
    Cytosone amount = Guanine amount
  • Alfred Hershey and Martha Chase

    Alfred Hershey and Martha Chase
    Experiment - radioactive isotopes in protein and DNA
    Contribution - DNA is the genetic material of a bacteriophage called T2
  • Maurice Wilkins and Rosalind Franklin

    Maurice Wilkins and Rosalind Franklin
    Experiment - x-ray crystallographic photo
    Contribution - basic shape of DNA is a helix
  • James Watson and Francis Crick

    James Watson and Francis Crick
    Experiment - made a model of a DNA strand to match a photograph with prior knowlegde
    Contribution - shape is a double helix; positiion of nitrogen bases; diameter of DNA = 2nm, Nitrogen bases are 1/3 nm apart
  • Marshall Nirenberg

    Experiment - synthesized RNA molecule by linking together identiical RNA nucleotides
    Contribution - dechiphered first codon