Question

Describe the Hershey-Chase experiment with labelled diagram. Write the conclusion drawn by the scientists after this experiment.

Hint:

The Hershey-Chase experiment was a critical turning point in molecular biology, establishing DNA as the genetic material.

Answer 1

Step 1: Overview of Hershey-Chase Experiment. - The Hershey-Chase experiment (1952) was a landmark study that helped confirm that DNA, not protein, is the genetic material in living organisms.
Step 2: Experimental Procedure. - Hershey and Chase used radioactive isotopes to label DNA and protein in bacteriophages. - Phosphorus-32 (P-32) was used to label the DNA because DNA contains phosphorus but no sulfur. - Sulfur-35 (S-35) was used to label the protein coat because proteins contain sulfur but no phosphorus.
Step 3: Inoculation and Observation. - The labeled bacteriophages were allowed to infect E. coli bacteria. After infection, the bacteria were examined for the presence of radioactivity.
Step 4: Results. - It was observed that only the DNA entered the bacterial cell, while the protein coat remained outside. This indicated that DNA is the material that carries genetic information.
Step 5: Conclusion. - The Hershey-Chase experiment concluded that DNA is the genetic material responsible for inheritance in living organisms.

Final Answer: The Hershey-Chase experiment provided strong evidence that DNA, not protein, is the genetic material, as only labeled DNA entered bacterial cells during infection.