Transformation experiment was first performed on which bacteria : -
A
E. coli
B
Diplococcus pneumoniae
C
Salmonella
D
Pasteurella pestis
The answer is B.
Solution
Frederick Griffith (1928) performed the transformation experiment with Diplococcus (Streptococcus) pneumoniae. He used the virulent S strain (smooth, capsulated) and the non-virulent R strain (rough). Mice injected with heat-killed S strain mixed with live R strain died, and live S strain bacteria were recovered from them. So some 'transforming principle' from the dead S cells had changed the R cells into S cells. Avery, MacLeod and McCarty later showed that this principle is DNA. So transformation was first demonstrated in Diplococcus pneumoniae.
ConceptGriffith's transformation experiment
Molecular Basis of Inheritance in past papers
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