State the experimental question being tested in the Hershey-Chase experiment

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Explain the procedure of the Hershey and Chase experiment.

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Hershey and Chase (H&C) performed their experiments on viruses that infect bacteria called bacteriophages. They incorporated radioactive isotopes of phosphorus and sulfur into phages. DNA contains phosphorus, but not sulfur, whereas protein contains sulfur, but not phosphorus. Therefore, when H & C marked phages with radioactive isotopes of those elements, they placed separate, distinguishable tags on the protein and DNA parts of the phages.

They allowed the phages to replicate by infecting bacteria. By tracking the location of the radioactive tags, H&C showed that phages only injected their DNA into host bacteria, and that the DNA served as the replicating genetic element of phages. The phages did not inject their protein coats into the bacteria; the protein coats remained outside the bacteria adhered to the bacterial membranes.

Explain how the results of the Hershey and Chase experiment supported the notion of nucleic acids as the genetic material.

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The molecule of heredity must be passed from generation to generation. When Hershey and Chase demonstrated that radioactively tagged DNA is present across generations of bacteriophages and that radioactively tagged protein is not, they demonstrated that nucleic acids must be the genetic material.