Final answer:
If transformation did not occur in Griffith's experiment with the injection of live R and heat-killed S cells, the mouse would survive and only live R cells would be isolated.
Step-by-step explanation:
The expected outcome of Griffith's experiment if transformation did not occur, and the mouse was injected with only live R (non-virulent) cells and heat-killed S (virulent) cells of Streptococcus pneumoniae, would be that the mouse would survive. This is because the live R cells alone cannot cause pneumonia, and the heat-killed S cells are not capable of causing infection, since they are no longer viable. In absence of transformation, the R cells would not acquire the virulence factors from the S cells necessary to cause a lethal infection. Therefore, the correct answer is:
a) The mouse would survive, and only live R cells would be isolated.