Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


the cell theory and the scientists that contributed toward this theory

in this presentation the many contributions made by scientists towards the cell theory will be displayed.

sukhman chahal

on 17 September 2012

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of the cell theory and the scientists that contributed toward this theory

the cell theory all stared with an idea there were many and i mean many! contributions towards this theory the ancient greeks: the greeks were very advanced for there time which was about 400 B.C.
they were known for creating and making use of what we call the inquiry process. there was a particular philosopher by the name of Aristotle who had developed a cause and effect type of question called a "hypothesis" which in today's modern day is used by scientists as well to create a statement. many greek scientists rather thought about possible outcomes towards the questions they faced instead of testing them. but Aristotle made careful observations and did tests followed by reasoning and interpretation rather than think of an outcome which was what helped him leap from normal to extraordinary. Aristotle made careful observation and descriptions of more than 500 animal species! and set up a classification system which was supported by his observations. he used for runner of methods used by modern scientists.

But it wasn't until the microscope was created that scientist were able to see and understand the building blocks of life. Last step (cc) image by nuonsolarteam on Flickr Antoni van Leeuwenhoek: time of contribution
1674 Antoni van Leeuwenhoek was a linen merchant in the town of delft and was obsessed with lenses. he was actually a master lenses crafter able to craft lenses that were almost spherical. he also created his own "viewing machine" which allowed him to view single celled organisms he had named "animalcules" . the microscope Leeuwenhoek had created was the most powerful one of his time, up to 500x magnification! which was a major break through in the 1600's he was also the first man to ever be able to see a human sperm which congregated the idea of were did life come from? which also allowed our future scientists to discover how fertilization accrued. time of contribution
400 B.C. Robert Hooke: time of contribution:
1655 Robert Hooke was some what a microbiologist in the 1600's, he was part of the royal society in London. he also wrote a very famous book called "Micrographia" which contained detailed drawing of animalcules and small organism such as a flee. he used his own made microscope but it was not near as powerful as Leeuwenhoek but he did try many different things to improve it such as, cramming in more light into the microscope and trying different lenses. after many tries he finally managed to see the "little animals" for the first time, giving the royal society a chance to recruit Leeuwenhoek into there society and giving all the credit to Leeuwenhoek for his discovery of the animalcules. Aristotle: 384 B.C - 322 B.C 1632–1723 A.D 1635-1703 A.D Hans and Zacharias Janssen: time of contribution
1595 Zacharias (1580-1638) is generally believed to have been the creator of the compound microscope the accomplishment has been recorded around the 1590's. many believed that his father, Hans Janssen had also help Zachrias with his work. they both worked as spectacle makes in the town of Middleburg located in Holland. the microscope they had created wasn't very powerful up to 20x magnification but it was a scientific breakthrough because of this scientist could now observe small creatures such as insects more closely leading closer towards the cell. Zacharias Francesco Redi: time of contribution
1668 and thats the conclusion to..... cell theory! Franseco Redi (1626-1697) was a Italian physician and a poet. around his time there was and idea that was afloat, an idea about life just springing out of inanimate objects. this theory was called "spontanius generation" but Francesco questioned the belief that maggots appeared out of no where from raw meat so Redi set up an experiment to test his hypothesis. he set out 3 jars with raw meat put in them. one jar had a sealed lid another had been covered in a gauze and the last one was left open. he had then observed that the maggots were only found in the jar with the open lid because flies could access the meat through the open lid and lay there eggs but they couldn't enter the jars that were sealed. but despite the effort and evidence the idea of spontaneous generation
still boomed until the time of Louis Pasteur... Robert Brown: time of contribution
1831 in 1831 Robert Brown (Robert Brown 1773-1858) was a Scottish botanist and botanical explorer. he to an expidition to the land of Australia in which he discover around 3000 new species of plants including many types of orchids. he used his own created microscope. he was fascinated by the movements of pollen grain and how plants reproduced he also studied each and every one of his 300o specimens of plants he had collected on his trip. Robert had noticed that there was a distinctive shape in the middle of each cell. Robert named the so called "distinctive shape" the nucleus. He also claimed that all plant cells contained a nucleus which was a turning point in the field of biology. his work on every cell containing a nucleus is still being used today. Louis Pasteur: Louis Pasteur(1822-1895) in is well known for being able to pasteurize milk but he had also created a major breakthrough on the topic of spontaneous generation In 1745, a man named John Needham(1713-1781) who was a English clergyman, proposed what he considered the definitive experiment. Everyone knew that boiling killed microorganisms, so he proposed to test whether or not microorganisms appeared spontaneously after boiling. He boiled chicken broth, put it into a flask with the mouth open, and waited and sure enough, microorganisms grew. Needham claimed victory for spontaneous generation. but later on Louis stated that the microorganisms landed into the broth from dust particles and didn't just generate the flash and to prove Needhams experiment wrong he created a new flask that let air in but not dust particles. it was a flask with a long slender curved neck in the sahpe of a S which was called a "swan neck". after a period of time in his experiment the flask with the swan neck did not contain any microorganisms what so ever and with that simple experiment the idea of spontaneous generation was abolished. and the cell theory started to advance. time of contribution
1864 T.S Schwann Time of contribution
1838 and M.J Schleiden T.S Schwann(1810-1882) took a position at the university in Berlin because he wanted to make a name of himself. during his research he kept finding the same globular structure also know as red blood cells. the university had believed that the make up of animals were completely different from the make up of plants which lagged them behind in there studies. M.J Schlieden(1804-1881) had also been studying cells but he was studing them in plants. he spoke passionately to Shwann about his research and how the cell made up many of the different plants and in return Shwann revealed his work on the nerves of the edible frog. they figured out that they were both made of the same materials-cells! becuase they both used the nucleus as a way to identify the cell. this sparked the idea of which everything was made of cells,this idea united all living organism and this very act got them titled as the founders of cell theory. Robert Remak and Rudolph Virchow Robert Remak(1815-1865) was jewish which made him getting his degree a struggle, he had to do most of his research in an old attic. he used eggs to see the developing embryo becuase thats were he believed lots of cells formed. he discovered that some of the red blood cells have been spliting into two. Virchow stated to Remak that this was probably a rare event that only accrued to red blood cells in developing chicks. Remak then changed his approach he started to use frog eggs for his experiments. Robert was the first one to ever witness cell division he saw the frog egg multiply from 2 cells to 4 to 8 to 16 and so on this was the final frontier and the main idea of were cells came from - other cells! with this research Robert Remak had founded the field of embryology. the forward motion of this theory changed our view on were we came from
and how we were made for this very theory many scientist had counquerd each portion slowly one at a time. time of contribution
1855 Hans fast forward through time..... Virchow(1821-1902) realized his friend was right so he took all of the credit by useing Remak's research and putting it into one of his medical text books and simply claimed it as his own, he even created his own phrase "all cells from other cells" but from this betrayal came forth the idea of cells coming from other cells which finnaly completed the theory of cells: every thing is made of cells, every cell contains a nucleus and every cell came from another cell. the design for there microscope went a little something like this: the microscope consisted of three draw tubes with lenses inserted into the ends of the flanking tubes. The eyepiece lens was bi-convex, meaning both sides of the lens were curved outward (convex) and the objective lens was Plano-convex which means that one side of the lens was flat but the other one was curved out, this microscope was also hand held. this microscope was very advanced for its time
Full transcript