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Gregor Mendel
Gregor mendel breed pea plants to determine how parents pass their genes onto their children. He used self-fertilization and cross-fertilization. Mendel discovered the fundamental principles of genetics, dominant and recessive alleles. -
Period: to
Genetics Timespan
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William Bateson and Reginald Punnett
They tested pea plants for flower color and pollen shape. By testing the pea plants, they discovered linked genes, genes located close together on the same chromosome. -
Thomas Hunt Morgan
Morgan crossed a wild-type fruit fry with a black body, vestigal wings fly. He found the ratio was different because linked genes and crossing over occured. He discovered the role of crossing over in heritance. -
Archibald Garrod
Garrod experimented with hereditary conditions like alkaptonuria. He discovered that an inherited disease reflects a person's inability to make a particular enzyme. -
Frederick Griffith
Griffith studied two varieties of the bacterium, one disease-causing and one harmless. He found that when he killed the disease causing bacteria with heat and mixed the cell remains with harmless bacteria. From this experiment, he found that some of the harmless bacteria turned to disease causing. -
George Beadle and Edward Tatum
Beadle and Edward discovered that each mutant was defective in a single gene. They found that one gene makes up one polypeptide, or protein. They studied strains of mold which caused mutations. -
Erwin Chargaff
Chargaff looked at the amount of adenine, thymine, guanine, and cytosine in different species. He discovered that the amount of adenine is equal to tyhe amount of thymine. Also the amount of guanine is equal to the amount of thymine. -
Alfred Hershey and Martha Chase
Hershey and Chase used different radio-active isotopes to label the DNA and protein in T2. Their experiment determined what the phage transferred to e. coli during infection was. They found that injected DNA molecules cause the cells to produce additional phages. -
Maurice Wilkins and Rosalind Franklin
Wilkins and Franklin discovered protein structures by mading a rope-ladder model of a double helix. -
James Watson and Francis Crick
Watson ansd Crick used wire models to construct a double helix. They determined the structure of DNA and that a double helix is made of two polynucleotide strands. They also found that adenine best bonds with thymine, and guanine with cytosine. -
Marshall Nirenberg
Nirenberg made a very simple nucleic acid composed of uracil. He deciphered the first codon, a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule. He found that RNA codon UU was the template for the amino acid phenylalanine.
