The scientists who worked on biochemical nature of ‘transforming principle’ were:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Oswald Avery, Colin MacLeod and Maclyn McCarty
In 1928 Frederick Griffith saw that heat-killed S-strain pneumococci could change living R-strain bacteria. He called the cause a ‘transforming principle’. Avery, MacLeod and McCarty then worked out what it was made of. They purified the chemicals of the heat-killed S cells and found that DNA alone could transform the R cells.
(1) Oswald Avery, Colin MacLeod and Maclyn McCarty — Correct. They gave the biochemical characterisation of the transforming principle.
(2) Frederick Griffith and Oswald Avery — Incorrect. Griffith only discovered transformation. He did not find its chemical nature.
(3) Alfred Hershey and Martha Chase — Incorrect. Their experiments with bacteriophages showed that DNA, not protein, is the genetic material that enters the bacterium.
(4) Matthew Meselson and Franklin Stahl — Incorrect. They showed that DNA replication is semi-conservative.
NCERT Extract:
The Search for Genetic Material – …
