name the scientists who followed it to show that dna is the transforming principle?? How did they prove it??

Dear student,
Please find below the answer:

The scientist who studied the 'Transforming Principle of DNA' extensively was Griffith. He performed the following experiment:

Griffith performed experiments with  the bacteria  Streptococcus pneumoniae . This bacterium has two strains − S strain and R strain.

S strain Bacteria	R strain Bacteria
Produce smooth colonies on culture plate	Produce rough colonies on culture plate
Have a polysaccharide coat	Do not have a polysaccharid e coat
Virulent (causes  pneumonia)	Non-virulent (does not cause pneumonia)

Griffith’s experiment

Live R strain in the presence of heat-killed S strain produces virulence because somehow R strain bacteria is transformed by heat-killed S strain bacteria. Hence, it was concluded that there must be transfer of genetic material.

Biochemical  Nature of Transforming Material

• Avery,  McLeod, and McCarthy worked to determine the biochemical nature of genetic material responsible for transformation.

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• This suggests that DNA  has to be the genetic material.

R strain of Streptococcus pneumonia is not virulent as it does not produce polysaccharide coat (virulence factor).

S strain of Streptococcus pneumonia is virulent due to the presence of polysaccharide capsule .

Hope this clears your doubt.
Regards.