What did Hershey-Chase experiments show about the genetic material in viruses?

What did Hershey-Chase experiments show about the genetic material in viruses?

• A. Protein coats carry genetic information.
• B. RNA carries genetic information.
• C. Carbohydrates carry genetic information.
• D. DNA carries genetic information.

Answer: (D)

The main point is identifying which molecule carries hereditary information in viruses. Hershey and Chase used bacteriophages and labeled DNA with radioactive phosphorus and protein coats with radioactive sulfur in separate experiments. After allowing infection, they split the virus shells from the bacterial cells and tracked which labeled material actually entered the cells and was passed to new viral progeny. They observed that the radioactive DNA entered the cells and became part of the new viruses, while the radioactive protein remained outside and did not appear in the offspring. This demonstrates that DNA is the genetic material in these viruses, not the protein coat. The other ideas—RNA carrying genetic information or carbohydrates doing so—are not supported by this experiment, and the data specifically argue against protein coats being the information-carrying molecule.

The main point is identifying which molecule carries hereditary information in viruses. Hershey and Chase used bacteriophages and labeled DNA with radioactive phosphorus and protein coats with radioactive sulfur in separate experiments. After allowing infection, they split the virus shells from the bacterial cells and tracked which labeled material actually entered the cells and was passed to new viral progeny. They observed that the radioactive DNA entered the cells and became part of the new viruses, while the radioactive protein remained outside and did not appear in the offspring. This demonstrates that DNA is the genetic material in these viruses, not the protein coat. The other ideas—RNA carrying genetic information or carbohydrates doing so—are not supported by this experiment, and the data specifically argue against protein coats being the information-carrying molecule.