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Gregor Mendel
Gregor Mendel self pollinated P-generation pea plants, then cross pollinated P-generation to get the F1-generation. He self pollinated F1 to get the F2 generation. In this experiment he discovered the Principle of Segregation and the Principle of Independent Assortment. -
William Bateson and Reginald Punnett
These two men crossed a purple flower with a white flower and found a 3:1 phenotypic ratio, but when group data was combined they did not find a 9:3:3:1 ratio like suspected. Instead, they found flower color and pollen shape located on the same chromosome, much later their discovery was called linked genes. The Chromosomal Theory of Inheritence was a result of their experiment. -
Thomas Hunt Morgan
Thomas Hunt Morgan crossed a heterozygous female fruit fly and a homozygous recessive male to find a 25% chance for each type of fly. When he combined group data he found 17% of the results were off. This led him to discover genetic variations such as crossing over and genetic recombinations. The Chromosomal Theory of Inheritence was the big discover in his experiment. -
Archibald Garrod
Archibald Garrod looked at urine samples and analyzed alkaptonuria, which makes urine black. He made a hypothesis that genes dictate phenotypes through enzymes, and that the proteins catalyze the chemical process. His hypothesis was later proven correct. This experiment he proformed gave us the ideas of transcription and translation. -
Frederick Griffith
Frederick Griffith took 2 varities of bacterium (pathogenic and harmless), and he heated the pathogenic pnemonia and killed it. He mixed that with harmless living bacteria and discovered some of the cells were converted into pathogenic form after injected into mice. All the offspring of that bacteria was injected into more mice, who all died, proving that the bacteria's offspring inherited the pathogenic form. With this experiment he was able to prove the genetic role of DNA. -
George Beadle and Edward Tatum
George Beadle and Edward Tatum let mold grow very large on bread and then observed it. They let the mold reproduce, and then observed their offspring. They next exposed the mold to x-rays to cause mutations and concluded with a hypothesis that one gene specifies the production of one enzyme. -
Erwin Chargaff
Erwin Chargaff studied all different types of organisms and examined the proportions of different DNA bases. He discovered that all organisms have the same amounts of thymine as adenine and the same amounts of cytosine as guanine in their DNA. -
Alfred Hershey and Martha Chase
Alfred Hershey and Martha Chase mixed radioactive phages with bacteria and infected them. They next seperated phages, in a blender, from bacteria. After that they put it in a centrifuge (large very fast merry-go round) to seperate the particles. After the particles had seperated, they measured the amount of radioactivity in each level. They found the most radioactivity was found in DNA for one, and in proteins in the other. This was the experiment that proved that DNA was genetic material. -
Maurice Wilkins and Rosalind Franklin
While in a lab run by Maurice Wilkins at King's College in London, Rosiland Franklin took many x-ray crystallography pictures that revealed the basic helix shape of DNA. Wilkins was credited with the discovery, until many years later Franklin was finally credited for her discovery. -
James Watson and Francis Crick
Watson and Crick used the images taken by Rosiland Franklin and all the other past descriptions of DNA to create a large wire model of nucleotides. They successfully created a double helix model, in their experiment, and are created with the idea of the double helix shape of DNA. -
Marshall Nirenberg
Marshall Nirenberg synthesized the amino acid phenylalanine using the RNA codon UUU, to find out that U matched up with DNA's A. This experiment credited Nirenberg with the discovery of how genetics operates in protein synthesis.
