Spontaneous Generation- production of living organisms from nonliving matter Francesco Redi -In 1668, Francesco Redi, an Italian scientist, designed a scientific experiment to test the spontaneous creation of maggots by placing fresh meat in each of two different jars. Redi successfully demonstrated that the maggots came from fly eggs and thereby helped to disprove spontaneous generation
Louis Pastuer- Louis Pasteur designed an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing microbes. Doing this he discoverd the existence of Bacteria.
Biogeneis- the synthesis of substances by living organisms
Modern Ideas
Scientists hypothesize that two things happened before life could appear on Earth. The first is that there had to be organic molecules-molecules containing carbon. The second is that the organic molecules must have formed into more complex molecules such as proteins, carbohydrates, and nucleic acids. These are the materials that are absolutely necessary for life. Miller and Urey -In the 1950's, biochemists Stanley Miller and Harold Urey, conducted an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere
Evolution of Cells
life on Earth consisted of bacteria They converted our mostly carbon dioxide atmosphere into a largely oxygen-based atmosphere. Endosymbiont Theory- suggests that mitochondria and plastids in eukaryotic cells were once independent prokaryotic cells. Basically, this means that once upon a time, there were three prokaryotic cells: one that was capable of aerobic respiration and converting energy, one that was capable of photosynthesis and one that was incapable of doing either of these processes. The lazy cell that was incapable of doing respiration and photosynthesis engulfed - or ate - the other cells.