Questions: A sample of food is dehydrated, which kills all the bacteria. However, in a few days, bacteria-free water is added to the food in a bacteria-free environment. Nevertheless, microscopic investigations indicate that bacteria are in the food. How did the bacteria get there?

The bacteria likely got there through the process of spore formation. Some bacteria can form spores, which are highly resistant structures that can survive extreme conditions, including dehydration. When the food was dehydrated, the bacteria may have formed spores to survive the harsh conditions. Once bacteria-free water was added, the spores could have germinated into active bacteria, leading to their presence in the food despite the initial dehydration process.

In summary, the bacteria were likely present in the form of spores, which survived the dehydration and later germinated when conditions became favorable again.