Question

what happened when griffith mixed heat - killed bacteria with the live harmless culture of bacteria? there was no change. the harmless bacteria caused pneumonia. the harmless bacteria died.

Explanation:

In Griffith's experiment, the heat - killed pathogenic bacteria transferred a 'transforming principle' to the live harmless bacteria, making the harmless bacteria pathogenic and able to cause pneumonia.

Answer:

The harmless bacteria caused pneumonia.