Presentation on theme: "Griffith’s work on Pneumococcus. Frederick Griffith (1920) was a medical officer in London. He was looking for a way to fight pneumonia in the epidemics."— Presentation transcript:
Frederick Griffith (1920) was a medical officer in London. He was looking for a way to fight pneumonia in the epidemics after World War I. The discovery was made as he heated to 60°C instead of 100°C, killing the pneumococcus bacteria but not destroying their DNA. This scientist changed genetics. pneumococcus bacteria
Pneumococcus bacteria - a kind of Streptococcus bacteria - cause severe pneumonia, meningitis, septicaemia, and ear infections.
After the experiment, Frederick Griffith drew out two hypotheses : 1.The dead S strain had been reanimated/resurrected. 2.The Live R had been transformed into Live S by some "transforming factor" Transformation Principle
Further experiments led Griffith to conclude that number 2 was correct. In 1944, three other scientists revisited Griffith's experiment and concluded the transforming factor was DNA. Helix structure of DNA