Which of the following is a prediction based on the cell theory that all organisms are made of cells, and all cells come from preexisting cells? 1. if you boil nutrient broth and place it in an air-tight flask, cells will appear in the broth2. cells are produced only from pre-existing cells3. if you boil nutrient broth and place it in an air-tight flask, no cells will appear in the broth4. cells arise spontaneously from nonliving material

3. If you boil nutrient broth and place it in an air-tight flask, no cells will appear in the broth.

Explanation:

Prior to cell theory, theory of abiogenesis was considered as a valid theory of evolution and it was believed that living forms come from non living forms gradually. In the bank of river, if there are so many frogs then it was believed that the small stones beside the river bank gradually evolved to become frogs.

But the findings of Louis Pasteur's experiment in which he boiled nutrient broth in an air tight flask gave a big blow to the theory of abiogenesis and it was discarded. Louis Pasteur proved that when the nutrient broth is boiled which killed all the existing micro-organisms and placed in an air tight flask then no micro-organism i.e. cell appeared in the broth. It simply indicates that living forms i.e. cell can only appear from pre-existing cell not from abiotic matter like nutrient broth.

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