Which of the following statements are correct for Griffth experiments?

(i) Frederick Griffith did experiments with Streptococcus pneumoniae.

(ii) Mice infected with the S strain die from pneumonia infection but mice infected with the R strain do not develop pneumonia.

(iii) Heat-killed S strain bacteria injected to mice did not kill them.

(iv) Mixture of heat-killed S and live R bacteria injected into mice then the mice died, and living S bacteria recovered from the dead mice.

(v) Some ‘transforming principle’ called genetic material transferred from the heat-killed S strain to R strain bacteria and enabled the R strain to become virulent.

(vi) The biochemical nature of genetic material was not defined from this experiment.