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Friedrich Miescher
Miesher isolated a unique chemical substance, called nuclein, by white blood cell. he found nuclein in every type of cell type he tested -
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levene and the components of DNA
Levene identified the component of DNA and RNA, and also proved that DNA molecules were made made of a sring of nucleotide unites linked together throught the phosfate groups. Levene tought that the chain was composed of only four nucleotides ( adenine,guanine, cytosine and thymin) in equal amounts, and he didn't realize that the DNA molecule carried genetic information -
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Oswald avery
Oswald Avery and his co-workers discovered that DNA is the material of which gene and chromosomes are made. -
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James Watson and Francis Crick
Watson and Crick published the first accurate model of DNA molecule. They tought that if DNA had a fixed, repetitive sequence, it would't be intelligent to carry information but the known that the DNA is intelligent so they tought that the order of nucleotide change -
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Rosalind Franklin
rosalind franklin contributed to the study of DNA providing an X-ray diffraction image of DNA ehuch led to the discovery of the DNA double helix