We trace the discovery of the genetic role of DNA back to 1928.
-While attempting to develop a vaccine against __, __studied Streptococcus pneumonia, a bacterium that causes pneumonia in mammals.
oHad two strains of the bacterium, one __(disease-causing) and one __(harmless).
oSurprised to find that then he killed the __bacteria with heat and then mixed the cell remains with living bacteria of the __strain, some of the living cells became __.
oFurthermore, this newly acquired trait of __was inherited by all the descendents of the transformed bacteria.
§Some chemical component of the dead pathogenic cells caused this heritable change, although the identity of the substance was not known.
- Frederick Griffith