The Development of the Cell Theory Biology 11 Prepared by: Ms. Bowie

The Cell Theory States: As written by Rudolph Virchow (1821-1902): All living organisms are made of one or more cells. Cells are the basic units of structure and function in all organisms. All cells come from previously existing cells. The activity of an entire organism depends on the total activity of its independent cells.

They pass on their understanding orally. Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 Ancient Times Ancient peoples are always on the look-out for ways that organisms can be used by them. They pass on their understanding orally. Some civilizations support “great thinkers” – and philosophers, but they rarely base their thoughts on observation or experiments.

Greek philosopher, Aristotle, begins to observe nature. Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 334 B.C.E - Aristotle Greek philosopher, Aristotle, begins to observe nature. He classifies all known organisms as either a Plant or and Animal. He writes that living things can arise spontaneously from non-living matter.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1268 – 1st Eyeglasses Roger Bacon, an English friar makes reference to a pair of eye glasses. This means that glass is being developed and used in a way that makes it easier to see small things.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1500’s Most European’s think that knowledge is unchangeable and should not be questioned. To find answers about nature, they look to the original teachings of Aristotle.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1590 – 1st Microscope Zacharias Janssen, a Dutch eyeglass maker, makes the 1st microscope by placing two lenses on top of one another to make extra-large images.

1600’s People start to question the origins of life. Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1600’s People start to question the origins of life. Many begin to suggest that life can only come from other forms of life rather than through spontaneous generation (as was suggested by Aristotle). This only took about 2000 years! William Harvey says that maggots do not come from the meat itself but from tiny eggs too small to be scene. William Harvey English Physician 1578-1657

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1665 – 1st Cells Seen Robert Hooke (1635-1703) publishes a book that shows illustrations of tree bark lining as seen through a simple compound (2 lens) microscope. William Harvey English Physician 1578-1657

The beginning of the end of spontaneous generation! Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1667 – Species Defined John Ray (1627-1705) defines a “species” as a set of individuals that can reproduce their own kind. The beginning of the end of spontaneous generation! William Harvey English Physician 1578-1657

1668 – 1st Experiments about origins of maggots Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1668 – 1st Experiments about origins of maggots Francesco Redi (1626-1697) conducts experiments to prove that maggots do not appear in meat if flies cannot land on it! William Harvey English Physician 1578-1657

1674 – 1st Microscopic Beasties Seen! Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1674 – 1st Microscopic Beasties Seen! Anton van Leeuwenhoek (1632-1723) reports being able to see tiny beasties (0.002 mm) using a simple single-lens microscope. William Harvey English Physician 1578-1657

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1700’s Microscope claimed to be an instrument of evil when a prominent person was horrified by the sight of a magnified flea! Scientists begin to doubt spontaneous generation, but the common people still believe in it!

1753 – Birth of Classification Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1753 – Birth of Classification Carolus Linnaeus (1707-1778) begins to show people the great diversity of living things by exploring methods of classifying them into 5 main Kingdoms.

1770 – Advancement of Microscopes Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1770 – Advancement of Microscopes Microscopes become sturdier and easier to use. Flaws in glass production still causes images to be blurry and have coloured halos.

1800’s – Support for Science Grows Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1800’s – Support for Science Grows Lots of interest in science Public lectures are popular The wealthy mount expeditions to collect new specimens The HMS Investigator goes on a 5 year voyage of discovery.

1809 – 1st Science Texts for Students Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1809 – 1st Science Texts for Students Jane Haldimand (1769-1858) writes textbooks for young people to learn about science. Terms such as “cell”, “cellular system” and “Cellular tissue” appear in the book.

1820’s – Better Glass = Better Lens Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1820’s – Better Glass = Better Lens Microscope quality improves with the production of better glass. Many English companies compete to produce the best microscope.

1825 – Book “Cells from Cells” Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1825 – Book “Cells from Cells” Francois Vincent Raspail (1794-1878) wrote a book called (translated from Latin) “Every cell is derived from a preexisting cell”. This again puts to rest the idea of spontaneous generation.

Scientists begin to study the cell extensively! Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1830 – Cells are studied Biology is becoming an important science and the body of knowledge is growing, especially since the improvement of microscopes. Scientists begin to study the cell extensively!

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1831 – Nucleus of Cell Found Robert Brown (1773-1858) is the 1st to consider the nucleus as a regular part of a living cell. The nucleus is still hard to see though without the invention of the electric light for his microscope.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1838 – Plant cells! Matthias Jacob Schleiden (1804-1881) makes the claim “All plants are made of cells”. Cells are alive!

“All living things are made of cells” Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1839 – Animal cells! Theodor Schwann (1810-1882) makes the claim “All animals are made of cells”. “All living things are made of cells” Cells are the basic building blocks of life!

“The cell is the basic unit of life”. Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1845 – Cell Basic Unit of Life Alexander Carl Heinrich Braun (1805-1877) makes the claim: “The cell is the basic unit of life”. Cells are made of protoplasm enveloped by a flexible membrane.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1850’s Biological knowledge advances, especially in the areas of medicine, botany and zoology!

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1856 – Staining technique developed 18 year old, William Henry Perkin (1838-1907) develops a new purple dye for staining cell parts making it easier to see cell parts with a microscope.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1858 – Article on Evolution Charles Darwin (1809-1882) & Alfred Wallace (1823-1913) read their article on “Tendency of species to form variations”.

Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1858 – Cell Theory Outlined Rudolph Virchow (1821-1902) develops his Cell Theory that is still largely accepted today.

1860’s – The end of the “Spontaneous Generation” debate Timeline of the discoveries, thoughts and technologies that led to the development of the Cell Theory 500 BCE 1000 1600 1800 300 BCE 1500 1700 1900 1860’s – The end of the “Spontaneous Generation” debate Louis Pasteur (1822-1895) conducts a series of experiments that once and for all put to rest the idea of spontaneous generation and concluding that living organisms do not arise from non-living matter. http://videos.howstuffworks.com/hsw/9699-cells-and-genetics-cell-theory-video.htm

Let’s see a recap of this info: http://www.youtube.com/watch?v=4OpBylwH9DU