Read the the given statements and answer the questions that follow :-
When Streptococcus pneumoniae bacteria were grown on a culture plate some produced smooth shiny colonies and others produced rough colony. Mice infected with the S strain died from pneumonia infection but mice infected with the R strain didn't develop pneumonia. When Griffith heat killed the S strain bacteria and injected it into the mice, the mice did not die .While on the other hand when he injected S strain heat killed bacteria with live R strain into the mice ,they died.
When Streptococcus pneumoniae bacteria were grown on a culture plate some produced smooth shiny colonies and others produced rough colony. Mice infected with the S strain died from pneumonia infection but mice infected with the R strain didn't develop pneumonia. When Griffith heat killed the S strain bacteria and injected it into the mice, the mice did not die .While on the other hand when he injected S strain heat killed bacteria with live R strain into the mice ,they died.
Why did the mice die on adding of heat killed S strain with live R strain?
Answer & explanation
Correct answer: option 2
Griffith concluded that the R strain bacteria had somehow been
transformed by the heat-killed S strain bacteria. Some ‘transforming
principle’, transferred from the heat-killed S strain, had enabled the
R strain to synthesise a smooth polysaccharide coat and become virulent.
This must be due to the transfer of the genetic material.