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Gregor Mendel
Experiement - he test crossed pea plants
Contribution - traits are inherited from parents -
William Bateson and Reginald Punnett
Experiment - tested 2 characteristics in pea plants; crossed double heterozygous plants
Contribution - punnett squares; linked genes -
Thomas Hunt Morgan
Experiment - observing inheritance of traits in fruit flies
Contribution - effects of crossing over -
Archilbald Garrod
Experiment - observed inherited disease alkaptouria
Contribution - genes dictate phenotypes through enzymes -
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
polynucleotide chains; A paired with T; C paired with G
Contribution - Adedine amount = thymine amount
Cytosone amount = Guanine amount -
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
Experiment - x-ray crystallographic photo
Contribution - basic shape of DNA is a helix -
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
