-
Mendel's Experiment
Mendel bred two phenotypes of flowers purple and white, The first generation was all purple but the second generation had 3/4 purple and 1/4 white. He disproved blending theory and discoverd laws of segregation. Found out about dominent and reccessive genes -
William Bateson and Reginald Punnett's Discoveries
He was crossing traits of pea plants and expected the 9:3:3:1 ratio but discovered linked genes. He discovered exceptions to Mendel's rules and discovered linked genes -
Thomas Hunt Morgan
He crossed fruit flies to see how often they looked liked the parents and how oftern they looked different. With this he discovered recombination frequency. This also includes crossing over. -
Archibald Garrod's Hypothesis
He was able to hypothesise that genetic disabilities are caused by the inability to create a certain enzyme. He introduced the idea that genes dictated phenotypes through enzymes. The enzymes will catalyst a chemical process. -
Fredrick Griffith
He was testing phenonia on mice. One was lethal and one was harmless. He found when he heated the lethal the deadly bacteria were killed and the mouse lived. But when he heated the harmless and lethal one the mouse died. What he really discovered was transformation. -
George Beadle and Edward Tatum
Studied bread mold that could not grow on the usual growing curve of bread mold. They found that every single one that couldn't grow normally lacked the same enzyme. The found each mutant was defective in a single gene and enzymes caused genetic disorders. -
Edwin Chargaff
He discovered that the amound of adenine in DNA is equal to the amount of Thymine. This discovery lead us closer to finding what DNA looked like and lead us closer to finding out that they were linked (A linked with C) -
Alfred Hershey and Martha Chase
He used radio active isotopes to label DNA and protein. When they settled out after being mixed he found the changed cells contained the other DNA but not the proteins. He discovered that DNA not proteins was in control of phenotypes and genetics -
Maurice Wilkins and Rosalind Franklin
They saw an X-ray crystallography photograph of DNA. Found that it was 2 nm in diameter. Found that it was made up in two polynucleotide strands. With their new knowledge they found out that DNA was in a double helix. -
James Watson and Francis Crick
They constructed a model of DNA. They found out the the Sugar phosphate molecules were on the outside and the nitrogen bases were on the inside. Also discovered that if they were paired AA and CC it would cause bulges. Discovered A+C and B+D were paired -
Marshall Nirenberg
Sythesised an RNA molecule. He discovered that UUU which meant the 3 of these would produce a certain amino acid and that there is a different combination for every amino acid.
