• Theory of abiogenesis or spontaneous generation was finally disapproved by Louis Pasteur.
• Louis Pasteur by careful experimentation demon strated that life comes only from pre-existing life.
• Swan-necked flask experiment was performed by Louis Pasteur.
• He showed that in pre-sterilised flasks, life did not come from killed yeast while in another flask open to air, new living organisms arose from ‘killed yeast’.