We have learned a great deal in the field of genetics over the last century. Many scientists have spent their whole lives studying genetics. These scientists discovered many vaccines and cures for diseases. We now have a better understanding of how heredity, DNA, chromosomes, and many other things play a part in every life. .

             The first group of scientists that started work with genetics was focused on working with vaccines. Edward Jenner started this with the discovery of a vaccine for small pox. That discovery impacted society greatly because many lives were saved. Many more vaccines came about after that discovery. Another great discovery of this time was the realization of how characteristics are inherited. Gregor Mendel discovered this. He also formed the theory of independent assortment, the principle of segregation, and invented the terms dominant and recessive. Mendel"s work later helped scientists with the discovery of chromosomes. .

             Through the late 1800"s and early 1900"s the work of the earlier scientists was expanded on. Many facts were discovered about chromosomes. Fleming started this work by seeing chromosomes and discovering Mitosis. He didn"t really know what the chromosomes were for. Edmund B. Wilson then discovered the sex chromosomes and the significance of X and Y-chromosomes. He realized that females have XX chromosomes, and the males have XY. More work was done by many scientists to understand what chromosomes were for and what they did.

             That work was then expanded on by the scientists of the mid 1900"s. Rosaline Franklin started the work done with DNA. She worked with x-ray diffraction and discovered the double helix. Her work was actually sold to Watson and Crick. They then expanded on her work and realized that the double helix was formed of pairs of proteins, such as adenine and guanine. We now began answering questions about DN@ what it was, why we have it, and what we could use it for.