Group 4 - Cell Theory Timeline by Saachi Padasalgi https://padlet.com/spadasal/ueqfcb8hyo08xqbr By: Vedika, Saachi, Jason, and Siya en-us 2020-10-26 14:01:27 UTC 2023-05-14 10:59:49 UTC hello@padlet.com http://www.assignmentpoint.com/wp-content/uploads/2013/06/animal-cell.jpg Jean Baptiste Lamarck-1809 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861790330 Lamarck found that acquired traits were inherited. These characteristics could then be passed to their offspring. Lamarck's first law was "Philosophie zoologique". This law stated, "a change in the environment causes changes in the needs of organisms living in that environment, which in turn causes changes in their behavior. Altered behavior leads to greater or lesser use of a given structure or organ; use would cause the structure to increase in size over, whereas disuse would cause it to shrink/disappear. His second law stated that all of these changes were heritable.

Sources:
https://ucmp.berkeley.edu/history/lamarck.html#:~:text=Of%20these%2C%20Philosophie%20zoologique%2C%20published,states%20Lamarck's%20theories%20of%20evolution.&text=He%20also%20anticipated%20the%20work,not%20formed%20by%20cellular%20tissue.]]> 2020-10-26 14:08:10 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861790330 Louis Pasteur - 1859 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861791331 Louis Pasteur disproved spontaneous generation which is his contribution to cell theory. He was the first scientist to prove that cells can only form when pre-existing cells are found. He proved this through an experiment which showed that cells would only form in broth when it was exposed to the air.

Sources: 
]]> 2020-10-26 14:08:22 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861791331 Matthias Schleiden and Theodor Schwann - 1838 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861792161 Matthias Schleiden, a botanist, and Theodor Schwann, a zoologist, studied tissues and created the unified cell theory. This unified cell theory states that: all living things are composed of one or more cells, cells are the basic unit of life, and they come from existing cells. They found that cells are present in both animals and plants.

Sources:]]> 2020-10-26 14:08:32 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861792161 Fracesco Redi - 1668 spaliwal https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861793987 Fracesco Redi denounced the theory of spontaneous generation. Spontaneous generation is the hypothesis that living organisms can come from nonliving things. To rebuttal this hypothesis, Redi designed an experiment. He wanted to test the creation of maggots by putting fresh meat in three different jars. The first jar was open while the second was covered with gauze, the final jar had a cork lid covering the opening. A couple days later, the open jar had maggots inside and the other jar had maggots on the surface of the cloth, meanwhile the jar with the lid had no organisms in it. This experiment helped debunk the theory of spontaneous generation.

Sources: https://www.infoplease.com/math-science/biology/genetics-evolution/origin-of-life-spontaneous-generation

]]> 2020-10-26 14:08:54 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861793987 Robert Hooke - 1665 spaliwal https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861795223 In 1665 a scientist named Robert Hooke looked at a thin piece of cork under a microscope. He noticed the cork had these tiny little boxes, Hooke later named these boxes cells since they resembled monastery cells. Hooke was the first person to use the word "cell" to describe these tiny organisms. 



Sources: https://ucmp.berkeley.edu/history/hooke.html
https://bio.libretexts.org/Courses/Community_College_of_Vermont/Human_Biology_(Gabor_Gyurkovics)/03%3A_Cells/3.02%3A_Discovery_of_Cells_and_Cell_Theory

]]> 2020-10-26 14:09:10 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861795223 Rudolf Virchow-1855 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861800019 Rudolf Virchoow utilized the theory that all cells come from pre-existing cells is the base of cellular pathology (study of diseases in organs tissues and cells). He basically reasoned that all cells come from pre-exisisting from cell division through observing cells dividing (mitosis) and reproducing. His work proved that diseases occur at the cellular level. Thanks to his studies and work, scientists can now diagnose diseases more proficiently.  He was the first to correctly link the origin of cancer from normal cells with the thought that cancer is caused by the severe irritation in the tissues.      


Sources: 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5665122/ 
https://study.com/academy/lesson/rudolf-virchow-discovery-cell-theory-contributions.html#:~:text=Virchow%20used%20the%20theory%20that,to%20diagnose%20diseases%20more%20accurately.



]]> 2020-10-26 14:10:10 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861800019 James Hilier and Albert Prebus- 1938 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861801134 James Hillier and his colleague Albert Prebus worked on the construction of an electron microscope. Unlike an optical lens does, an electron lens focuses a beam of electrons. An electron microscope would be able to reveal smaller objects than any object raw to the eye. Moreover, Hillier also discovered the stigmator for correcting astigmatism of electron microscope objective lenses. Prebus however,  went on to an academic career, building a second microscope and becoming a respected expert on the atomic structure of materials.

Sources:
https://magazine.utoronto.ca/campus/history/seeing-new-worlds-first-north-american-electron-microscope-james-hillier-albert-prebus-janet-rowe/
https://www.the-scientist.com/daily-news/james-hillier-dies-46863
https://www.microscopy.org/images/posters/Hillier.pdf]]> 2020-10-26 14:10:24 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861801134 Anton van Leeuwenhoek-1676 vsingh25 https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861831459 Leeuwenhoek created a powerful simple microscope and was one of the first to observe living cells and describe them. His first findings were animalcules which were mostly single-called organisms that were found in bodies of water. In 1676, he made observations of many microscopic organisms including blood cells, sperm cells, and he egg cells of small insects such as fleas. His discoveries while observing fleas changed peoples thinking's on the idea of spontaneous generation. Spontaneous generation was the idea that fleas emerged spontaneously from sand or dust.

Sources:
https://www.nationalgeographic.org/article/history-cell-discovering-cell/]]> 2020-10-26 14:16:29 UTC https://padlet.com/spadasal/ueqfcb8hyo08xqbr/wish/861831459