Final answer:
In the Hershey-Chase experiment, radioactive sulfur and phosphorus were used to label proteins and DNA, respectively. The results of the experiment indicated that DNA is the genetic material, not proteins.
Step-by-step explanation:
In the Hershey-Chase experiment, two radioactive isotopes were used to label different molecules. Radioactive sulfur (35S) was used to label proteins, while radioactive phosphorus (32P) was used to label DNA.
Since proteins contain sulfur and not phosphorus, only the viruses labelled with radioactive sulfur would cause the supernatant to become radioactive if protein was the molecule responsible for heredity. However, the supernatant did not become radioactive in the experiment, indicating that DNA is the genetic material.
Therefore, it was concluded that DNA, not proteins, is responsible for heredity.