Final answer:
The question concerns the differential bacterial growth exhibited in two flasks with endospores of different ages exposed to a pollutant. Flask B, with 100-year-old endospores, is expected to have more prolific growth than flask A which contains 20-year-old endospores. This is because the older endospores may evolve resistance to the pollutant more rapidly upon first exposure.
Step-by-step explanation:
The question relates to the expected growth of bacteria in two different flasks, A and B, containing endospores from different time periods in a controlled experimental setting. According to the scientific context provided, the 100-year-old endospores in flask B will show more prolific growth compared to the 20-year-old endospores in flask A when both are introduced to a growth medium and a pollutant. This expectation is based on the assumption that the older endospores formed before the marsh was contaminated with the pollutant, hence, they are initially not resistant to it. However, once exposed, they would potentially evolve resistance to the pollutant more quickly than the endospores that had already been exposed to the pollutant during their formation (the 20-year-old ones), leading to a greater growth in flask B.
This scenario echoes the principles observed in Pasteur's experiment, where a flask's content remains sterile until it is directly exposed to microorganisms after breaking the protective neck of the flask, thus allowing microbial growth.