Griffith's transformation experiment (1928)ग्रिफिथ का रूपांतरण प्रयोग (1928)

Class 12 Biology · Chapter 5 · interactive diagram

Parts and their functions

• Live S strain (जीवित S प्रभेद) — Smooth colonies; mucous (polysaccharide) coat; virulent — mice die of pneumonia.
• Live R strain (जीवित R प्रभेद) — Rough colonies; no coat; mice do not get pneumonia.
• Heat-killed S strain (ताप से मारा S प्रभेद) — Killed by heat; injected alone, mice live.
• Heat-killed S + live R (मारा S + जीवित R) — Mice die and live S bacteria are recovered: R was transformed by a "transforming principle" from dead S.

Steps

1. S strain kills the mouse.
2. R strain is harmless.
3. Heat-killed S is harmless.
4. Heat-killed S + live R kills the mouse; live S recovered — transformation.

Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake