AP BIOLOGY

Detailed explanation-1: -Spallanzani found significant errors in the experiments conducted by Needham and, after trying several variations on them, disproved the theory of spontaneous generation.

Detailed explanation-2: -Needham, along with many other scientists of his time period, staunchly believed in spontaneous generation among microorganisms. He conducted an experiment in the hope of supporting the idea of spontaneous generation, and he published his results in 1750. His study concluded that spontaneous generation did occur.

Detailed explanation-3: -The Greek philosopher Aristotle (384–322 BC) was one of the earliest recorded scholars to articulate the theory of spontaneous generation, the notion that life can arise from nonliving matter. Aristotle proposed that life arose from nonliving material if the material contained pneuma (“vital heat”).

Detailed explanation-4: -In England, John Needham challenged Redi’s findings by conducting an experiment in which he placed a broth, or gravy, into a bottle, heated the bottle to kill anything inside, then sealed it. Days later, he reported the presence of life in the broth and announced that life had been created from nonlife.

Detailed explanation-5: -The experiments consisted of briefly boiling a broth mixture and then cooling the mixture in an open container to room temperature. Later, the flasks would be sealed, and microbes would grow a few days later. Those experiments seemed to show that there was a life force that produced spontaneous generation.