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Unformatted text preview: Cell theory All organisms made up of cells Robert Hooke First person to start looking at organisms under a microscope Looked at cork, saw it as a structure Came up with cell theory Antoine van Leeuwenhoek Studied infusions liquids ie rain drops, soup, saliva, pond water Discovered tiny organisms living in water Animacules microorganisms, bacteria, etc. 1 Supported idea of single-cell organisms Spontaneous generation Life can be generated from nonlife Francesco Redi Believed in Biogenesis Experimented to prove this theory Put steak in a jar and covered it with mesh, then left a control jar with steak but without mesh After a few days the jar with mesh did not have worms Concluded that worms come from the flies landing on the steak, the worms are not generated out of the dead steak Biogenisis Cells only come from other cells Life comes from life John Needham Believed that abiogenesis exists at a microscopic rather than macroscopic scale, for example: fermentation and putrefaction Experimented to prove this theory Boiled water, transferred it to a clean flask, and a few days later bacteria grew in the flask The new flask was contaminated by bacteria falling in through the neck Fermentation and putrefaction Fermentation the souring of wine to vinegar Putrefaction the rotting/decay of meat Lazzaro Spallanzani Redid Needhams experiment, but sealed the top of the new flask after transferring the boiled liquid and microbes did not grow Louis Pasteur Identified a problem with past experiments and educated himself on past approaches and experiments Formed his hypothesis based on that information Designed a very clear experiment o Reproduced Needham and Spallazanis experiments o But he used a swan necked flask so that cells would fall into a curved neck, not into the flask or boiled liquid o No microbes grew in the flask, they all collected in the curved neck Disproved spontaneous generation Abiogenic System Same theory as spontaneous generation Idea that life can come from nonlife Swan-necked flasks Type of flask designed by Louis Pasteur John Tyndall Heat labile Heat-resistant Spore (endospore) Autoclave Aseptic technique Neutrons Uncharged subatomic particles Protons Positively charged subatomic particles Element Pure substances...
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This note was uploaded on 01/27/2012 for the course BIOL 100-31 taught by Professor J.campanella during the Summer '11 term at Montclair.
- Summer '11
- Cell Theory