A. Origin of Life- Scientists Hypotheses Disproving Spontaneous Generation (Word Bank: air, sealed, open, bacteria, gauze, spontaneously) Through the early 1800s, people believed organisms could develop, an idea known as spontaneous generation. In 1668, many believed maggots were spontaneous generated from rotting meat. Francis Redi’s experiment disproved this by experimenting with meat in open_jars, tightly snealed_jars and jars covered with cloth netting. It was also believed that bacteria spontaneously generated in broth. Lazzaro Spallanzani removed the from a flask, the broth and sealed the flask. No bacteria generated without exposure to the air. Some people still supported spontaneous generation but thought that air was a force, necessary for it to occur. In 1859, Louis Pasteur completely disproved spontaneous generation by using a special flask that allow in but captured bacteria before it could get to the broth. No grew in the flask after boiling = no spontaneous generation. 2. First Life (Word Bank: eukaryotes, prokaryotic, variety, self-replicating, organic, photosynthesis, oxygen) Earth’s atmosphere had to be very hot and with little oxygen for the first molecules to first form. Organic molecules clumped together for form structures that later evolved into cells. cells were the first to evolve. When cells gained the ability to do , they used up carbon dioxide and put more into the atmosphere.