In the 1920s, the field of genetics saw many groundbreaking discoveries. The research of scientists such as Thomas Hunt Morgan and Hermann Joseph Muller proved the existence of chromosomes and genes as well as showed how mutations can be influenced and passed on to offspring. Geneticists from this decade used study results to form a more complete understanding of previously constructed theories. Genetic research in the 1920s significantly advanced scientific thinking and understanding regarding heredity and evolution of species. As a professor of biology at Columbia University, Thomas Hunt Morgan, along with his colleagues, used his research to confirm the theory that genetic material is carried on chromosomes. “[He] further discerned
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Morgan’s research not only made popular the use of Drosophila, or fruit flies, in genetic research, but it also paved the way for mapping of “genomic evolution, cancer, neurodegenerative diseases, alcoholism, learning and memory, and genetic diseases” (A). Alfred H. Sturtevant, another geneticist concerned with gene mapping, also studied Drosophila and found that certain mutations could be repaired by way of another mutation, which further complicated the manner in which genes could be mapped. His work allowed other geneticists to apply concepts of gene mapping and repairable mutations to more complex animals and eventually humans …show more content…
Fredrick Griffith’s 1928 experiments with Streptococcus pneumoniae demonstrated that an unknown component, later found to be DNA, existed inside every living thing and had the power to pass on its genetic material to other organisms (B). In his experiments, Griffith injected groups of mice with different versions of the pneumonia-inducing bacteria. One such strain (strain S), which he observed as encapsulated and having a smooth outer surface, was known to be lethal to mice unless killed under very high temperatures, in which case it would no longer be virulent. Conversely, another strain (strain R) had a rough surface and was nontoxic to mice. In a third group of mice, Griffith injected a mixture of the heat-killed S strain and the live R strain; these mice developed pneumonia and died. Bacteria collected from the third group of mice was of the live S strain (C). Griffith’s discoveries showed that genetic material of a dead virulent bacteria could be passed to a live non-toxic strain and transform the latter into live virulent bacteria
Morgan’s research not only made popular the use of Drosophila, or fruit flies, in genetic research, but it also paved the way for mapping of “genomic evolution, cancer, neurodegenerative diseases, alcoholism, learning and memory, and genetic diseases” (A). Alfred H. Sturtevant, another geneticist concerned with gene mapping, also studied Drosophila and found that certain mutations could be repaired by way of another mutation, which further complicated the manner in which genes could be mapped. His work allowed other geneticists to apply concepts of gene mapping and repairable mutations to more complex animals and eventually humans …show more content…
Fredrick Griffith’s 1928 experiments with Streptococcus pneumoniae demonstrated that an unknown component, later found to be DNA, existed inside every living thing and had the power to pass on its genetic material to other organisms (B). In his experiments, Griffith injected groups of mice with different versions of the pneumonia-inducing bacteria. One such strain (strain S), which he observed as encapsulated and having a smooth outer surface, was known to be lethal to mice unless killed under very high temperatures, in which case it would no longer be virulent. Conversely, another strain (strain R) had a rough surface and was nontoxic to mice. In a third group of mice, Griffith injected a mixture of the heat-killed S strain and the live R strain; these mice developed pneumonia and died. Bacteria collected from the third group of mice was of the live S strain (C). Griffith’s discoveries showed that genetic material of a dead virulent bacteria could be passed to a live non-toxic strain and transform the latter into live virulent bacteria