Question

In F.Griffith's experiment,how did the non virulent strain of streptococus pneumonia become virulent

Answer 1

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⬛ Griffith conducted this experiment using a bacteria that cause pneumonia ( Streptococcus Pneumoniae ). He watched them producing some colonies while they were cultured in the laboratory. There were smooth ( S ) and rough ( R ) colonies. S strained was injected on a mice and it died. But when R strain was injected nothing happened to the mice.

S strain ( virulent ) 〜> ⏩ mice died
R strain ( Non-virulent ) 〜> ⏩mice lived

⬛ When, heat killed S strain is mixed with live R strain and when it injected to a mice, it died. This is because R strain bacteria got transformed by mixing it with heat killed S strain bacteria. The genetic material in S strain got transfered in to R strain bacteria and made polysaccharide coating upon it too. The ‘‘ presence of this smooth polysaccharide was responsible in getting infected by pneumonia and there by killing the mice ’’

S strain ( Heat killed ) + R strain ( live ) 〜>⏩ Killed the mice

♣Kimmus♣