Pasteur used swan-neck flasks in his experiments to test the validity of spontaneous generation.Suppose that after allowing the flasks to sit for a day, he had tilted one of these flasks so that the sterile broth entered the swan neck.Suppose he had then tilted the flask back to allow the broth to settle back into the round bowl of the flask before leaving it to sit undisturbed for another few days.What would have happened, and how would these results have affected conclusions about spontaneous generation?
A) The broth would have become cloudy from growth of microbes present in the flask neck, and that would have supported the idea that life comes from preexisting life.
B) The broth would have become cloudy from growth of microbes present in the flask neck, and that would have supported the concept of spontaneous generation.
C) The broth would have become cloudy as the result of microbes present in the original broth, and that would have supported the idea that life comes from preexisting life.
D) The broth would have remained clear as the result of sterilization by high heat, and that would have supported the idea that life comes from preexisting life.
E) The broth would have remained clear as the result of sterilization by high heat, and that would have supported the concept of spontaneous generation.

Question

Quizplus · Accepted Answer

Tipping the flask and allowing the broth to enter the swan neck would have allowed microbes present in the neck to enter the sterile broth. When the flask was tilted back, these microbes would have settled back into the round bottom of the flask with the broth. After a few days, the broth would have become cloudy due to the growth of these microbes, which would have been evidence that life comes from preexisting life rather than spontaneous generation.

Pasteur Used Swan-Neck Flasks in His Experiments to Test the Validity