Question

In 1861, Pasteur conducted his now-famous experiments using flasks with long necks bent into an S-shape. Imagine that you are a scientist working in Pasteur’s lab at this time. You decide to tip the flasks so that broth enters the long S-shaped neck. You then return the flask to its upright position. Predict the most likely outcome of tipping one of Pasteur’s S-necked flasks.

Microbes would grow in the broth because the tipping would introduce the oxygen necessary for microbial growth.
The broth would become contaminated with microbes because they were trapped in the neck.
Since the broth had been heated (effectively sterilizing it), no microbes would grow in the broth.
The broth would remain uncontaminated because no microbes could enter the long S-shaped neck of the flask.

Answer 1

The broth would become contaminated with microbes because they were trapped in the neck.

Step-by-step explanation:

When Pasteur heat the bottles, he made them sterilizing, and as the water was condensed in one part of the S neck, it will act as a sealing mouth, so in this way no microorganism could enter. But at the same time is open at the end, so in this way, the air with microorganism could enter, an pollute the water in the middle. The clue here is that this polluted water is not in contact with the broth. If the flask is tip, the broth and the water will be in touch, in this way it will pollute the broth and microbes will grow.