Question

In the Hershey and Chase experiment, how did labeling DNA and protein with different radioactive isotopes demonstrate that DNA, rather than protein, carried the genetic information in the T2 virus?

1) Researchers could track which part of the virus entered a bacterial cell.
2) Researchers could use radio labeling to inactivate DNA and protein in the bacteria.
3) Researchers could distinguish bacterial DNA from viral protein.
4) Researchers could better elucidate DNA or protein structure.
5) Researchers could monitor how DNA interacted with protein in the virus.

Answer 1

Hershey and Chase used radioactive isotopes to label the protein coat and DNA of the T2 bacteriophage, showing that only the DNA entered the bacterial cell, proving that DNA carried the genetic information in the virus.

Step-by-step explanation:

Hershey and Chase's experiment involved labeling the protein coat of the T2 bacteriophage with radioactive sulfur (³5S) and labeling the DNA with radioactive phosphorus (32P). By doing so, they were able to track the movement of the different radioactive isotopes in the virus.

When the bacteriophage infected the bacterial cell, only the 32P-labeled DNA entered the cell, while the ³5S-labeled protein remained outside. This demonstrated that DNA, not protein, carried the genetic information in the T2 virus.