Further Biology - Food and Drink from Microorganisms

Microorganisms, such as bacteria, cause changes in food. These are often bad but are sometimes useful and mean we can make foods we wouldn't have otherwise

The THEORY OF BIOGENESIS has been DEVELOPED over the years  

• People used to think that life could spontaneously generate from nin-living material
• Then evidence showed that this couldn't be the case - the theory supported the idea that living things are created from other living organisms - this is the theory of BIOGENESIS

HERE IS HOW THE ACCEPTED THEORY CHANGED TO FIT THE AVAILABLE EVIDENCE:

STAGE ONE

• Before 1765, it was believed that substances in foods were changed into microbes, which caused food to go off
• A scientist called Lazzaro Spallanzi boiled two sets of broth to kill the microbes then sealed one flask and left the other one open
• Only the open one went off
• This showed that microbes got into the food from the air, but opponents just thought it meant air from outside the flask was necessary to start the change

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