Louis-Pasteurs-Theory-of-Spontaneous-Generation.pptx

Cell theory

1. GROUP 4 Louis Pasteur’s Theory of Spontaneous Generation

2. Louis Pasteur’s Theory of Spontaneous Generation

3. Louis Pasteur’s Theory of Spontaneous Generation Louis Pasteur (1822-1895) was a French biologist regarded as he father of modern microbiology. He performed many experiments which provided important details and data, one of them focusing on ‘The Spontaneous Generation Theory’

4. Louis Pasteur’s Theory of Spontaneous Generation An experiment was conducted by Louis Pasteur to test whether microbes arise from pre-existing microbes or are generated spontaneously. In this experiment Pasteur designed and used a ‘Swan-Neck Flask’ for the experiment. The purpose of the flask was to exclude oxygen from entering the flask which stopped microorganisms in the air from contaminating the contents of the flask.

5. Louis Pasteur’s Theory of Spontaneous Generation To start the experiment, a ‘swan neck flask’ must be filled with an ‘infusion’ – which is a nutrient rich broth. The flask would then be boiled to eliminate the microorganisms present in the liquid and inside the flask – this process is called pasteurization. After that the infusion is left to rest. As the infusion cools down, it should be observed that there are no changes in the broth’s physical appearance.

6. Louis Pasteur’s Theory of Spontaneous Generation This scenario was explained by Pasteur as the microorganisms being trapped in the flask’s entrance. Therefore, it has not been contaminated