-
Gregor Mendel Part 1
In 1865 Gregor Mendel started the thirst for genetic knowledge with his studies of heredity in pea plants. His discoveries showed that there were dominant and recessive characteristics in genes and that genetic traits don’t mix but some mask others. -
Gregor Mendel Part 2
He started by cross breeding two yellow pea plants and two green. He found that the first generation of peas were all yellow whereas in the second generation it was a ratio of three yellow to one green. Mendel did this with thousands of plants to find out all the possibilities and to test his theory to make sure it was constant. He is now referred to as the father of genetics and greatly enhanced our knowledge of how genes are inherited. -
Friedrich Miescher Part 1
In 1869 Friedrich Miescher became the first person to isolate DNA. He began his work with blood cells found in pus which he collected from the bandages of the local hospital. -
Friedrich Miescher Part 2
He used a salt solution to get the pus off the bandages and when he added alkaline to the salt and pus solution the cell nuclei were able to be seen. He named the substance nuclein. Although he thought the substance was a protein he was the first person to actually isolate DNA and it was a very important step towards our genetic studies today. -
Thomas Hunt Morgan Part 1
In 1911 Thomas Hunt Morgan confirmed Mendel’s theory of heredity with his studies on fruit flies and he also confirmed the chromosomal theory of inheritance. This showed that genes are found on chromosomes and that some genes are linked. Their main studies began when they found a strange white eyed fruit fly compared to the regular red eyed fly. -
Thomas Hunt Morgan Part 2
When they cross bred it with the red fly the first generation of offspring all had red eyes and the second generation had a ratio of three red eyes to one white eye. This was the same ration as Mendel’s pea plants proving that the trait of red eyes was dominant. Morgan’s proof of the chromosomal theory of inheritance gave people proof that traits must be inherited from the parents of offspring. -
Rosalind Franklin Part 1
Rosalind Franklin was one of the four people who together discovered the double helix structure of DNA. At the time however her contributions were overlooked as she died before the others were awarded with a Nobel Prize. Franklin discovered that DNA when crystallised can be in two different forms. -
Rosalind Franklin Part 2
Along with Maurice Wilkins she used X-ray crystallography to reconstruct the positions of atoms. J.D. Bernal referred to her photographs as “the most beautiful X-ray photographs of any substance ever taken”. When Wilkins showed Watson one of Franklin’s photographs he figured out the solution and published it before Franklin who never received the credit she deserved. Without her contributions to genetics we would not have found out about the double helix structure at that period in time. -
James Watson and Francis Crick Part 1
I am going to treat Watson and Crick as a pair and not individuals as they worked together and they both contributed to the same discovery. In 1952 Francis Crick and James Watson became the first people to publish the theory of the double helix. This stated that the structure of DNA looked like a twisting ladder. -
James Watson and Francis Watson Part 2
However even though Crick and Watson were the first people to propose the theory it is believed that they might have taken information from Rosalind Franklin. Franklin did not receive any recognition for her work because she died before the 1962 Nobel Prize was awarded. Crick’s and Watson’s contributions towards science were incredibly important finding out how human and all other life forms genetics work. -
Francis Collins Part 1
Francis Collins joined the NIH (National Institute of Health) in 1993. He was head of the Human Genome project during the crucial years of mapping and sequencing all human DNA. By 2000 a draft of the human genome sequence was released and a year later it was published. -
Francis Collins Part 2
Now all the information they gathered is available to the scientific public. Francis Collins’s contribution to the genome project has led to the discovery of different strands of type 2 diabetes and the genes that cause scystic fibrosis, neurofibromatosis, Huntington's disease and Hutchinson-Gilford progeria syndrome.
