Genetics Timeline

Timeline created by kylie_carlson
  • Gregor Mendel

    Gregor Mendel
    Experiment:
    cross-fertilized pea plants
    1. Removed stamens from purple flower
    2. Ttransferred pollen from stamens of white flower to carpel of purple flower
    3. Pollinated carpel matured into pod
    4. Planted seeds from pod Contribution
    -different alleles
    -two genes, one from each parent
    -allele pairs separate during meiosis
    -one allele fully expressed, other no noticeable effect
  • William Bateson and Reginald Punnett

    William Bateson and Reginald Punnett
    Experiment:
    crossed doubly heterozygous plants that exhibited the dominant traits (purple flowers and long pollen grains) the corresponding recessive traits are red flowers and round pollen.
    Contribution
    -discovered linked genes
  • Thomas Hunt Morgan

    Thomas Hunt Morgan
    Experiment:
    Cross between a wild type fruit fly and a fly with a black body and vestigial wings (test cross)
    Contribution:
    -discovered crossing over and genetic recombination
  • Archibald Garrod

    Archibald Garrod
    Experiment:
    observed that when exposed to air, the patients with alkaptonuria's urine turns dark which lead to his conclusion that alkaptonuris is a congenital disorder.
    Contribution:
    -inherited disease reflects a person's inability to make a particular enzyme
  • Frederick Griffith

    Frederick Griffith
    Experiment:
    Used mice to determine which bacteria would kill them
    Contribution:
    -discovered tranformation
  • George Beadle and Edward Tatum

    George Beadle and Edward Tatum
    Experiment:
    Used orange bread mold which was unable to grow on the usual simple growth medium
    Contribution:
    -one gene-one enzyme (the function of an individual gene is to dictate the production of a single enzyme.
  • Erwin Chargaff

    Erwin Chargaff
    Experiment:
    Noticed a pattern in the model that he made. Toook sample of different DNA cells to find out A=T and C=G.
    Contribution:
    -amount of adenine=amount of thymine
    -amount of cytosine=amount of guanine
    -base-pairing rules
  • Alfred Hershey and Martha Chase

    Alfred Hershey and Martha Chase
    Experiment:
    -Used bacteriophage composed of only DNA proteins
    -DNA tagged by radioactive phosphorus and protein was tagged with radioactibe sulfur
    Contribution:
    -determined DNA was genetic material
  • Maurice Wilkins and Rosalind Franklin

    Maurice Wilkins and Rosalind Franklin
    Experiment:
    -took a photograph of DNA
    Contribution:
    -DNA was a helix
  • James Watson and Francis Crick

    James Watson and Francis Crick
    Experiment:
    -used wire models, tried putting the backbones on the outside and forcing the nitrogenous bases to swivel to the interior of the model
    Contribution:
    -DNA was a double helix made of 2 polynucleotide strands
  • Marshall Nirenberg

    Marshall Nirenberg
    Experiment:
    -set up a "cell free system" with "sap" from E. coli cells containing enzymes and an energy system
    -added simple chains of RNA and amino acids
    Contribution:
    -discovered first "triplet"- sequence of three bases of DNA codes for one of the 20 amino acids that serve as building blocks of protein