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Gregor Mendel~ "The Law of Heredity"
Gregor Mendel~ He gained posthumous recognition as the founder of the modern science of genetics. Mendel's work on pea plants, discovered the fundamental laws of inheritance. He tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. He observed the patterns of one generation going onto the next. Mendel's "Laws of Heredity" include "The Law of Segregation", "The Law of Independent Assortment", and "The Law of Dominance". -
Friedrich Miescher
Friedrich Miescher~ He isolated "nuclein," DNA with associated proteins, from cell nuclei. He was the first to identify DNA as a distinct molecule. He could be best known for his incorrect tetranucleotide hypothesis of DNA. Miescher had been given the task of researching the composition of lymphoid cells (white blood cells). He collected bandages from a clinic near him and wash off the pus. He began experimenting and isolated a new molecule (nuclein) from the cell nucleus. -
Frederick Griffith
Frederick Griffith~ Was a British bacteriologist whose focus was the epidemiology and pathology of bacterial pneumonia. Griffith's famous 1928 experiment showed that bacteria can distinctly change their function and form through transformation. When Griffith injected heat-killed S into mice, no disease ensued. When mice were injected with a mixture of heat-killed S and live R; pneumonia and death ensued. The live R had transformed into S—and replicated as such. -
Oswald Avery
Oswald Avery~ Avery was one of the first molecular biologists and a pioneer in immunochemistry, but he is best known for the experiment that isolated DNA as the material of which genes and chromosomes are made. Avery, along with his colleagues Colin MacLeod and Maclyn McCarty, reported that the transformation of pneumococcus bacteria from one type to another. They showed that DNA was the "transforming principle." -
Erwin Chargaff~ Was an Austro-Hungarian biochemist that immigrated to the United States during the Nazi era and was a professor of biochemistry at Columbia University medical school.
Discovered that in DNA the number of guanine units is equal to the number of cytosine units, & the number of adenine units is equal to the number of thymine units. This hinted at the base pair makeup of DNA. The relative amounts of guanine, cytosine, adenine & thymine bases vary from one species to another. This hinted that DNA rather than protein could be the genetic material. -
Rosalind Franklin
Rosalind Franklin~ She had produced the X-ray crystallography pictures of BDNA that Watson and Crick used to determine the structure of double-stranded DNA. Franklin was able to obtain two sets of high-resolution photos of crystallized DNA fibers. She used two different fibers of DNA, one more highly hydrated than the other. From this she deduced the basic dimensions of DNA strands, and that the phosphates were on the outside of what was probably a helical structure. -
Hershey & Chase
Hershey & Chase~ They worked with a DNA virus, called T2, which infects E. coli (and so is a bacteriophage). The two of them conducted multiple experiments that helped to confirm that DNA is genetic material. They concluded that DNA, not protein, was the genetic material. They determined that a protective protein coat was formed around the bacteriophage, but that the internal DNA is what conferred its ability to produce progeny inside a bacterium. -
Watson & Crick
They worked together on studying the structure of DNA. At that time Maurice Wilkins and Rosalind Franklin, both working at King's College, London, were using X-ray diffraction to study DNA. They showed that each strand of the DNA molecule was a template for the other. During cell division the two strands separate and on each strand a new "other half" is built, just like the one before. -
Collins & Venter
He was a biochemist-geneticist J. Craig Venter is acknowledged, along with geneticist Francis Sellers Collins,as being a primary force behind the Human Genome Project. Venter,with private funding,and Collins,with public funding, independently mapped and sequenced human DNA.Their reports appeared in 2001.A sheet of 5 stamps issued by Palau in 1999 provides an opportunity to honor J. Craig Venter indirectly.One of the stamps representing the Human Genome Project shows the overall structure of DNA.
