The answer is the second choice: variation, overpopulation, adaptation
They move by osmosis(a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.).
It’s because it’s been used when it’s appearing in all cells and it breaks down the interior of the cell.
Once purified, the isolated species can then be cultivated with the knowledge that only the desired microorganism is being grown.
A pure culture can be correctly identified for accurate studying and testing, and diagnosis in a clinical environment.
Testing/experimenting with a pure culture ensures that the same results can be achieved regardless of how many time the test is repeated.
