Griffith experiment
Griffith used two types of bacteria in his experiment
1. R-type: it was non-virulent and cause no disease in mice
2. S-type: It was virulent and cause disease in mice which lead to death.
However when heat killed S-type was applied no disease was occurred in mice. Then he mixed heat killed S-type and live R-type and injected it into mice. He was expecting that no disease will be caused in mice.
Results
However, mice was died.
Conclusion
He was confused from this experiment. But later it was confirmed by other scientists that DNA from heat killed S-type was shifted to R-type. the progeny which formed from this transfer of DNA were virulent and cause the death of mice.
significance
It was concluded from this experiment that DNA is a hereditary material which transfer characters from parents to offspring.