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Friedrich Miescher
Miescher first discoverd the deoxyribonucleic acid. He discovered a substance containing both phosphorus and nitrogen in the nuclei of white blood cells found in pus. He proved that deoxyribonucleic acid is in a cell and today we can know more about that. -
Rosalind Franklin
Franklins photographs clearly demonstrated that DNA was a double helix a finding that flatly contradicted the widespread theory that the structure had three chains.She took X-ray diffraction photographs of DNA that showed a helical form of the molecule, a finding confirmed by James Watson and Francis Crick. This proves that Watson and crick were correct about the double helix and helps us with the understanding of DNA today. -
Rosalind Franklin
Franklin discovered even more proof that the DNA was a double helix. By using her expertise and X-ray diffraction techniques on DNA fibers. Studying DNA structure with X-ray diffraction she was able to make out the DNA's structure. this also shows that this has helped us know more about the DNA molecule than ever before. -
Erwin Chargaff
Through careful experimentation, Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA. The first and best known achievement was to show that in natural DNA the number of G units equals the number of C units and the number of A units equals the number of T units. The second rule is that the composition of DNA varies from one species to another, in particular in the relative amounts of A, G, T, and C bases. This shows today the amounts of the bases. -
Alfred Hershey and Martha Chase
A series of experiments conducted that helped to confirm that DNA is genetic material. Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Although the results were not conclusive, and Hershey and Chase were cautious in their interpretation, previous, contemporaneous, and subsequent discoveries all served to prove that DNA is the hereditary material. -
Matthew Meselson and Franklin Stahl
their experiment supported the hypothesis that DNA replication was semiconservative. In semiconservative replication, when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. Meselson and Stahl decided the best way to tag the parent DNA would be to change one of the atoms in the parent DNA molecule. Thus proves the hypothesis DNA replication was semiconservative. -
James Watson, Francis Crick
Watson and Crick discovered the double helix, the molecule that is the basis for heredity, DNA, contains the patterns for constructing proteins in the body, including the enzymes formed by several scientific breakthroughs: the progress made by X-ray crystallographers in studying organic macromolecules; the growing evidence supplied by geneticists that it was DNA in chromosomes that was responsible for heredity. Modern biotechnology also shows its basis in the structural knowledge of DNA. -
James Watson, Francis Crick
Watson and Crick discoverd the double helix, the molecule that is the basis for heredity and contains the patterns for constructing proteins in the body. Formed by several scientific breakthroughs: the progress made by X-ray crystallographers in studying organic macromolecules; the growing evidence supplied by geneticists that it was DNA, not protein, in chromosomes that was responsible for heredity. this is modern biotechnology which also has its basis in the structural knowledge of DNA.
