Question

DNA is a genetic material - Prove it with the description of an experiment.

Hint:

Hershey-Chase experiment used radioactive labeling of DNA (³²P) and protein (³⁵S) to prove DNA is the genetic material.

Answer 1

The experiment that proved DNA as the genetic material was conducted by Avery, MacLeod, and McCarty, followed by confirmation through the Hershey-Chase experiment.

Hershey and Chase Experiment (1952):

• They used bacteriophages (viruses that infect bacteria) labeled with radioactive isotopes.
• DNA was labeled with radioactive phosphorus (³²P), and proteins were labeled with radioactive sulfur (³⁵S).
• The bacteriophages were allowed to infect bacterial cells, and the infected cells were analyzed.
• Radioactive phosphorus (³²P) was found inside the bacterial cells, whereas radioactive sulfur (³⁵S) remained outside.

Conclusion:

Since only DNA entered the bacterial cells and directed viral replication, it was concluded that DNA is the genetic material.