Question

Unequivocal proof that DNA is the genetic material was first proposed by

• A. Alfred Hershey and Martha Chase
• B. Avery, Macleoid and McCarthy
• C. Wilkins and Franklin
• D. Frederick Griffith

Answer 1

The Correct Option is A

The unequivocal proof that DNA is the genetic material was first provided by Alfred Hershey and Martha Chase. Their famous experiment, conducted in 1952, is known as the Hershey-Chase experiment. It used bacteriophages, which are viruses that infect bacteria, to demonstrate that DNA, not protein, is the genetic material.

In their experiment, Hershey and Chase labeled the DNA of the bacteriophages with radioactive phosphorus-32 and the protein coat with radioactive sulfur-35. After allowing the bacteriophages to infect E. coli bacteria, they used a blender to separate the phage coats from the bacterial cells. They then measured the radioactivity in the bacteria and found that only the phosphorus-32 entered the host cells, indicating that DNA was the material responsible for carrying genetic information. This experiment provided definitive evidence that DNA was indeed the genetic material.

Answer 2

In the Hershey-Chase experiment conducted in 1952, Alfred Hershey and Martha Chase used bacteriophages (viruses that infect bacteria) to show that DNA, rather than protein, is the genetic material. The experiment provided strong evidence that DNA carries the genetic information needed for viral replication within bacterial cells.

Therefore, The correct option is (A): Alfred Hershey and Martha Chase