Examine the experiments that Griffith performed using rough and smooth pneumococcus bacteria.

what type of material is being injected into the mouse

And

what effect it has on the mouse.

(There is a picture from left to right:

Rough strain (nonvirulent) = mouse survives

Smooth strain (virulent) = death of mouse

Heat-killed smooth stain = mouse survives

Rough strain & heat-killed smooth strain = Death of mouse)