[Campbell Biology P.365] What was the primary conclusion drawn from the Hershey-Chase experi... | Practice Question

What was the primary conclusion drawn from the Hershey-Chase experiment regarding the genetic material of phage T2, and which radioactive isotopes were specifically used to label proteins and DNA, respectively?

  • A: DNA is the genetic material; proteins were labeled with ³²P and DNA with ³⁵S.
  • B: Protein is the genetic material; proteins were labeled with ³⁵S and DNA with ³²P.
  • C: DNA is the genetic material; proteins were labeled with ³⁵S and DNA with ³²P.
  • D: Both DNA and protein are genetic materials; both were labeled with ³²P.

Explanation

The Hershey-Chase experiment conclusively demonstrated that DNA, not protein, is the genetic material of phage T2. They used radioactive sulfur ³⁵S to label proteins because sulfur is present in proteins but not DNA, and radioactive phosphorus ³²P to label DNA because phosphorus is present in DNA but not proteins. The results showed that only ³²P entered the bacterial cells to reprogram them, confirming DNA as the genetic material.