Final answer:
The statement is false; mice injected with the non-pathogenic R strain alone survived, while they died only when injected with a combination of live R strain and heat-killed S strain due to the transforming principle.
Step-by-step explanation:
The statement 'Mice injected with bacteria from rough colonies died' is false. In Frederick Griffith's transformation experiments, mice injected with the benign R (rough) strain bacteria survived. It was the combination of live R strain bacteria and heat-killed S (smooth) strain bacteria injected into mice that resulted in the death of the mice. Griffith concluded that there was a transfer of material ('transforming principle') from the heat-killed S strain to the live R strain, transforming the R strain into the pathogenic S strain and thus leading to the death of the mice when the transformed bacteria were virulent.
On the other hand, mice injected with the heat-killed S strain alone also survived, showing that the killed bacteria could not cause disease. Through these experiments, Griffith laid the groundwork for understanding that DNA is the substance that controls heredity and that there is a mechanism by which DNA can be transferred from one bacterium to another, changing its characteristics and virulence.