Griffith's Transformation Experiment — NEET Biology
📚 Practice ConceptWhen Streptococcus pneumoniae (pneumococcus) bacteria are grown on a culture plate, some produce smooth shiny colonies (S) while others produce rough colonies (R). This is because the S strain bacteria have a mucous (polysaccharide) coat, while R strain does not. Mice infected with the S strain (virulent) die from pneumonia infection but mice infected with the R strain do not develop pneumonia.
Which of the following statements are correct regarding the outcomes and implications of Frederick Griffith’s transforming principle experiment? S1. Mice injected with live S strain bacteria developed pneumonia and died. S2. Mice injected with live R strain bacteria did not develop pneumonia and survived. S3. Heat-killed S strain bacteria, when injected alone, caused pneumonia and death in mice. S4. When a mixture of heat-killed S strain and live R strain bacteria was injected, the mice died. S5. Griffith recovered living S strain bacteria from the dead mice in the experiment involving the mixture of heat-killed S and live R strains. S6. The experiment conclusively identified DNA as the chemical basis of the transforming principle.
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