Answer:
spontaneous generation
Explanation:
Spontaneous generation is the idea that living organisms arise from nonliving matter. Louis Pasteur was a French chemist who designed a series of experiments to determine whether a sterile nutrient broth could spontaneously generate microorganisms. He added nutrient broth to two flasks, curved their necks into S shapes, and finally boiled the broth to eliminate any potential microorganism. Pasteur did not observe any microorganisms in the flasks with the S-shaped necks, thereby showing that microorganisms present in the air were responsible for contaminating nonliving material and thus rejecting the idea of spontaneous generation.