Question

Which of the following was NOT an aspect of Pasteur's experiments to disprove spontaneous generation?

a) He boiled the infusions to kill any microbes present.
b) The flasks were incubated for very long periods of time.
c) The flasks he used were sealed with corks.
d) The flasks were free of microbes until they were opened.

Answer 1

Louis Pasteur's experiments did not involve flasks sealed with corks; instead, he used open swan-neck flasks to disprove spontaneous generation.

Step-by-step explanation:

The aspect of Louis Pasteur's experiments to disprove spontaneous generation that was NOT an aspect of his methodology was (c) The flasks he used were sealed with corks. Instead, Pasteur used flasks with a special swan-neck design. These swan-neck flasks were left open to the air, but their shape prevented airborne microorganisms from contaminating the broth inside. This design was critical because it allowed air to enter the flask but prevented the introduction of airborne microbes, supporting Pasteur's argument against spontaneous generation. When the broth in these flasks was boiled and then allowed to cool, the sterility was maintained as long as the swan neck was intact. The moment these swan necks were broken, allowing microorganisms to enter the flasks, contamination occurred. Pasteur's careful design and observation irrefutably disproved spontaneous generation and supported the idea that all life comes from preexisting life, summarized in his statement 'Omne vivum ex vivo'.