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)
Griffith's experiments involved injecting different types of pneumococcus bacteria into mice to observe their effects. The two types of bacteria used were the rough strain (nonvirulent) and the smooth strain (virulent).
In Griffith's experiments, he injected the bacteria into the mice. The material being injected into the mouse was a suspension of the bacteria.
The rough strain of bacteria, when injected into the mice, did not cause any harm. The mice survived after being injected with the rough strain.
On the other hand, when the smooth strain of bacteria was injected into the mice, they died. The smooth strain of bacteria is virulent, meaning it is pathogenic and can cause illness or death.
To understand the effect of heat-killed bacteria, Griffith also injected mice with heat-killed smooth strain bacteria. In this case, the mice survived. The heat-killed bacteria are unable to cause infection or illness as their cellular components are denatured or destroyed by the heat.
Griffith made a significant observation when he injected a combination of the rough strain and heat-killed smooth strain bacteria into the mice. Surprisingly, the mice died. This observation led to the discovery of bacterial transformation, where the genetic material from the heat-killed smooth strain bacteria was taken up by the rough strain bacteria, making them virulent.
In summary, the mice injected with the rough strain survived, while those injected with the smooth strain died. Heat-killed smooth strain bacteria did not cause harm, but a combination of the rough strain and heat-killed smooth strain bacteria resulted in the death of mice due to bacterial transformation.