Question

What properties of the bacteriophages made them ideal material for solving the controversy regarding the genetic material to be protein or DNA ?

Answer 1

Hershey and chase by their experiment confirmed that DNA is the genetic material.

The DNA of bacteriophage enters the host cell and carries the necessary information for the formation of new phages.

Two types of phage particle were taken, one with radioactive Sulphur and one with radioactive Phosphorus.

These were produced by growing the bacteria with radioactive Sulphur and radioactive Phosphorus these were then separated and made to infect normal bacterial cell.

When these normal bacterial cells were analysed by radioactivity, no radioactive sulphur was reported and only radioactive phosphate was reported in the bacterial cells, which were infected with radioactive phosphorous phages.

It is because sulphur does not form a part of DNA and phosphorus only forms a part of DNA.

Bacteriophages were selected for this procedure because of the ability to infect any host cell and carry the transformation in their genetic material.