Which experiment confirmed that DNA is the genetic material in bacteriophages?

Which experiment confirmed that DNA is the genetic material in bacteriophages?

• A. Griffith Transformation Experiment
• B. Avery-MacLeod-McCarty Transformation Experiment
• C. Hershey-Chase Blender Experiment
• D. Meselson-Stahl Experiment

Answer: (C)

The key idea is identifying which molecule acts as the genetic material during phage infection. In the Hershey-Chase blender experiment, bacteriophages were labeled in two ways: one label marked the protein coats with radioactive sulfur, and another label marked the DNA with radioactive phosphorus. After allowing infection of bacteria and then using a blender to separate phage coats from the bacterial cells, only the DNA label was found inside the cells and passed into new phages. This shows that DNA, not protein, carries the genetic information in bacteriophages. Earlier work showed that genetic information can be transferred (Griffith) and that DNA can act as the transforming principle (Avery), but Hershey-Chase specifically demonstrated, in a viral system, that DNA is the molecule responsible for heredity. Meselson-Stahl, meanwhile, clarified how DNA replicates, not which molecule is genetic material.

The key idea is identifying which molecule acts as the genetic material during phage infection. In the Hershey-Chase blender experiment, bacteriophages were labeled in two ways: one label marked the protein coats with radioactive sulfur, and another label marked the DNA with radioactive phosphorus. After allowing infection of bacteria and then using a blender to separate phage coats from the bacterial cells, only the DNA label was found inside the cells and passed into new phages. This shows that DNA, not protein, carries the genetic information in bacteriophages.

Earlier work showed that genetic information can be transferred (Griffith) and that DNA can act as the transforming principle (Avery), but Hershey-Chase specifically demonstrated, in a viral system, that DNA is the molecule responsible for heredity. Meselson-Stahl, meanwhile, clarified how DNA replicates, not which molecule is genetic material.