Spontaneous Generation and Cell Theory

Spontaneous magazines and prison carrell Theory 1. Tradition thought is very hard to overcome- regular with solid evidence to support sweet ideas * Social pressure has onus on acceptance of scientific ideas and technological advancements * Science is a affectionate/political enterprise * New ideas often met with resistance * Sometimes ostracisms, persecution, decease * Microscope helped to overturn about strange ideas * Disease processes * w palsieding propagation Attitudes and skills of scientific inquiry (questioning, predicting, observing and recording) atomic number 18 inevitable to provide unbiased and existent info * Investigations must follow ethical guidelines and results must be ordered under controlled conditions * Example of way that science, technology and society are united is found in phylogenesis of the current understanding of the way accompaniment cadres function * Microscope provided technology to explore the world of microscopic particles and org anisms * Then attainable to obtain evidence for or against generally authentic opinions or theories somewhat donjon thingsSpontaneous Generation 2. Believed that brio can emerge from non-living matter 3. A superstition- people unaware of microscopic forms of living * e. g. mice created from mixing wheat husks with sweaty undergarments * Maggots and move emerge spontaneously from raw warmheartedness * Francesco Redi * Example of scientific method * Believed flies pose eggs on meat * Experiment to shew hypothesis Limited access to meat ( line of credit, no fresh air, flies, no flies) 4. Idea that life could emerge spontaneously from non-living matter = widely accepted from time of the Romans through and through to the 19th century * Even in time of Robert Hooke and Antoni van Leeuwenhoek * Believed that to produce mice, you put a sweaty underwear and husks of wheat in an pioneer jar and after 21 days, the sweat and husks would combine and spay the husks into mice 5. 668, Francesco Redi (Italian physician and poet) questioned belief that maggots appeared from raw meat * He believed that flies laid their eggs in the meat * Set up audition to raise his hypothesis * Set out flaskfuls containing raw meat but some were sealed, some were covered in gauze and some were open to the air * Controlled the access of flies to the meat * Maggots were found only in the flasks that were open and accessible to flies to lay their eggs * Despite evidence, idea of spontaneous propagation still thrived 6.John Needham (proving that living things could be produced from non-living matter) boiled chicken line and put it in a flask and sealed it * Everyone accepted that boil killed micro-organisms since boiling was a common method of removing substances that would make one ill * However, in his experiment, micro-organisms continue to appear * Suggested that there was a life guide that produced spontaneous generation 7.Lazzaro Spallanzani (Italian priest) claimed that th ere were micro-organisms in the air that were responsible for the new ontogenesis * Re-did Needhams experiment but drew off the air in the flask, nothing grew in the remaining broth * Critics suggested that all Spallanzani had shown was that air was required for spontaneous generation to occur * Spontaneous generation theory continued to be accepted 8. 859, French Academy of Sciences announced a oppose for the best experiment to prove or disprove spontaneous generation * Louis Pasteur used the doing of Needham and Spallanzani with important change * Before boiling meat broth in flask, Pasteur heated the neck of the flask and bent it into an S shape * Air could reach the broth but micro-organisms and other particles would occur caught in the S- bend * Nothing grew in this broth but if the flask were tipped so that the broth reached the S-bend in the neck, moulds would later appear 9.Pasteur controlled his experiment in that he used the corresponding broth, same type of flasks an d same light and temperature conditions * Controlled shiftings (conditions that are held constant throughout an experiment) broth type, flasks type, light, temperature * Manipulated ariable (condition deliberately changed in an experiment) access of dust to the flask * Responding variable (condition that changes in response to the manipulated variable in an experiment) ability to grow mould in the broth * Had observational control, a part of the experiment which the manipulated variable is not changed in some(prenominal) way from its everyday condition * Flask in which dust had normal access to the broth after boiling * Result moulds occurred * Experiment intervention Prevent the access of dust to the broth, resulting in evidence of no growth of mould * To allow access of dust to the broth very briefly, resulting in evidence of mould growth * Strong evidence that says that spontaneous generation doesnt occur, but also that micro-organisms are found in the air * His work opened new doors to microbiology, immunology, biochemistry and gave credibility and new importance to the processes of conducting controlled experiments, maintaining detailed records of observations, and connecting results to conclusionsThe Cell Theory 10. Importance of prison cell as the functional unit of life was recognized with the improvements in lens technology and increased number of observations do by scientists in several countries 11. 1833, Robert Brown identified an important cell structure, the nucleus, in study of orchids * Saw an shady granular spot within the cell * Others had seen it too but he was the first to recognize at this cell structure must have something for cell function 12. 1838, M. J.Schleiden notice that all plants were composed of cells and he proposed that the nucleus was the structure responsible for the development of the remainder of the cell * Discussed his work with a friend (Theodor Schwann), who was studying tool physiology * Schwann believed tha t there must be similarities btwn plant and animal tissue * When Schwann searched for opaque spots in animal tissue, he found structures that resembled the cells that botanists were studying in plant tissue and the nucleus structure that Brown and Schleiden had identified 13. 839, Schleiden and Schwann proposed the cell theory as a result of observations of plant and animal specimens through the microscopes * All plants and animals were composed of cells and that the cell was the basic unit of all organisms 14. 1859, cell theory was further extended by Rudolf Virchows statement that all cells renegade only from pre-existing cells Cell Theory 15. All living things are made up of one of more cells and the materials produced by these cells 16. All life functions take place in cells, making them the smallest unit of life 17.All cells are produced from pre-existing cells through the process of cell division 18. Applies to all living things regardless of size, shape or number of cells in volved * Subcellular particles (viruses and prions) fall into fellowship that is neither living nor non-living although they may exhibit certain characteristics of living cells 19. examine in support of cell theory came from Pasteurs experiment to investigate the design of spontaneous generation in micro-organisms * Cell theory has become the footing of the study of biology