Experiments timeline.

Francesco Redi's experiment involved placing decaying meat in jars. Jars covered with gauze allowed air but not flies to reach the meat, while others were left uncovered. Maggots appeared only in the uncovered jars, refuting the idea of spontaneous generation and supporting the concept that life comes from pre-existing life. This experiment challenged prevailing beliefs in the 17th century and contributed to the understanding of biogenesis

John Needham's experiment in the 18th century involved boiling nutrient broth and sealing it in containers. Despite his efforts, microorganisms still appeared in the broth, leading him to support the idea of spontaneous generation. However, his results were later challenged by Lazzaro Spallanzani's experiments, which suggested that Needham's contamination could have happened after boiling

Lazzaro Spallanzani's broth experiment in the 18th century involved boiling nutrient broth and sealing one set of flasks while leaving another open. The sealed flasks remained free of microorganisms, contradicting Needham's results. Spallanzani argued that microorganisms entered Needham's open flasks after boiling, supporting the idea that spontaneous generation wasn't possible

Louis Pasteur's experiment disproved the theory of spontaneous generation definitively. Pasteur used a specially designed flask with a long, curved neck that allowed air to enter but prevented microorganisms from reaching the nutrient broth. He boiled the broth to sterilize it and observed that no microorganisms grew, even after long periods. This experiment demonstrated that life does not spontaneously arise from non-living matter under these conditions