Question

Which result of Frederick Griffins experiments led him to believe in a transforming principle

A) mice inject with live S bacteria died
B) mice inject with live R bacteria lived
C) mice inject with dead S bacteria lived
D) mice inject with dead S and live R bacteria died

Answer 1

Mice injected with a combination of dead S bacteria and live R bacteria dying led Frederick Griffith to propose the transforming principle, implying genetic material transfer from dead S to live R bacteria made the latter virulent.Option b is the correct answer.

Step-by-step explanation:

The result of Frederick Griffith's experiments that led him to believe in a transforming principle was the observation that mice injected with a mixture of dead S (smooth) bacteria and live R (rough) bacteria died.

This occurred because the dead S bacteria had a capsule that could not alone cause death since the mice lived when injected with just the dead S bacteria.

However, when mixed with live R bacteria, which are typically nonvirulent, the mice unexpectedly died. The subsequent recovery of live S bacteria from the dead mice suggested to Griffith that something from the dead S strain had transformed the live R strain into a deadly S strain capable of causing pneumonia.