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Hooke first penned what came to be known as cell theory- the idea that all living things are composed of cells
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Redi attempted to disprove spontaneous generation.
Redi placed raw meat into two different containers. The first he sealed so that flies could not enter the container. The second container he left open. As expected, flies laid eggs in the meat which later became maggots. Some said that sealing the container kept out the "vital force" needed to make the maggots. Redi recreated the experiment, but only used cheescloth to cover the one container. The flies laid their eggs on the cheesecloth and no maggots were present on the meat. -
Leeuwenhoek was the first to create and use a microscope to see the microscopic world of what he called "animalcules."
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Carolus Linnaeus created the system of scientific nomenclature that we still use today.
Each organism has two names: the genus and the specific species. Spontaneous generation was still a very popular theory in Linnaeus' time. -
Needham experimented with boiled nutrient broth.
Needham, who was a believer in spontaneous generation, performed an experiment by boiling nutrient broth. He left the container of boiled broth open and later observed bacteria growth. He erroneously concluded that spontaneous generation did occur. -
Spallanzani recreated Needham's experiment, but sealed the flasks of nutrient broth.
Spallanzani did not agree with spontaneous generation and sought to correct errors in Needham's experiment by sealing the flasks of nutrient broth to prevent contamination. Many followers of spontaneous generation believed that the experiment was faulty because they claimed that air was needed for spontaneous generation. -
Jenner discovered that inoculation with cowpox could cause immunity to small pox.
Jenner experimented on his own son by inoculating him with cow pox. He then later exposed his son to small pox to see if he would contract the illness. He had first developed this theory after noticing that milk maids did not seem to get small pox. -
Bassi showed that silkworm disease was caused by a fungus.
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Semmelweis advocated that hand washing would prevent the spread of disease from one patient to another.
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Virchow claimed that all cells arise from preexisting cells.
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Joseph Lister used chemical antiseptic to prevent surgical wound infections.
Before this time, surgery would have most likely ended in death. Lister proved that by disinfecting the surgical environment, washing hands, and disinfecting surgical tools, disease could be prevented. -
Pasteur demonstrated that germs are in the air all around us.
Pasteur experimented with nutrient broth in long necked flasks. He first boiled the broth, then placed into flasks. He then bent the neck of the flask to created a place where the bacteria from the air would collect and not enter the broth. The flasks were left open to the air to appease those that argued that the absence of air interfered with spontaneous generation. Thus Pasteur ended all viable argument for spontaneous generation. -
Pasteur discovered that by boiling a liquid and then sealing it, you can prevent bacterial growth.
Pasteur is credited with creating the process that we now refer to as "Pasteurization." Because of his discovery, we can drink pasteurized milk without worrying about ingesting bacteria. -
Koch discovered that certain organisms cause a certain disease.
Koch did further research to prove what was later titled "Koch's Postulates." He stated that to prove that an organism was the cause of a disease, you must obtain an isolated specimen, culture it, inject it into a healthy test subject, and then see if the healthy test subject developed the same illness. -
Ehrlich developed a synthetic arsenic drug to treat syphilis.
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Alexander Fleming accidentally discovered penicillin.
Fleming noticed that mold inhibited the growth of certain bacteria that were growing on culture plates. -
Rebecca Lancefield classified streptococci based on their cell wall components.
Lancefield's contribution led to a major advance in immunology. -
Lederberg conducted experiments to study gene replication and recombination in bacteria.
Lederberg and Zinder showed that genetic material could be transferred from one strain of bacteria to another using transduction. -
Carl Woese established three domains for microbes.
Carl Woese (biogenesis) noted that there were many differences between bacteria and archaea and argued that there would be three domains- bacteria, archaea, and eukarya. -
Doherty discovered how the body's immune system distinguishes virus infected cells from normal cells.
