AIM: What is the Cell Theory & How was it developed?? Discuss with your neighbor what the following quote tells us about the origin of new life. Quote: “Fireflies rise from the morning dew, fish and frogs from a muddy stew, maggot worms from rotting meat and mice shall come from sweat and wheat.”

What is Spontaneous Generation? the belief that living things can come from non-living things. Was once thought to be true, but is now known to be false! How was it disproved? - the following scientists with their combined experiments proved the theory of spontaneous generation to be false & helped develop the Cell Theory.

Who was… Francesco Redi? (1668) scientist whose experiments proved maggots did not come from rotting meat.

Who was…Robert Hooke? (1665) - English Scientist who discovered cells while looking at a thin slice of cork (tree bark) He described the cells as tiny rooms/boxes Thought that cells only existed in plants and fungi

Who was…Antonie van Leewenhooke? 1673 Used a handmade microscope to observe pond scum & discovered single-celled organisms He called them “animalcules” He also observed blood cells from fish, birds, frogs, dogs, and humans Therefore, it was known that cells are found in animals as well as plants

Who was…Matthias Schleiden? (1838) Onion cells Elodea cells studied numerous plant parts under the microscope and declared “ALL PLANTS ARE MADE OF CELLS!”

Who was… Theodor Scwhann? (1838) Cheek cells Amphibian Blood Used a microscope to observe numerous animal tissues and declared “ALL ANIMALS ARE MADE OF CELLS!”

Who was… Rudolf Virchow? (1839) - observed living cells dividing and declared “ALL CELLS COME FROM OTHER LIVING CELLS!”

These scientists discoveries led to the cell theory… What is the CELL THEORY??? Theory that states… All organisms are made of one or more cells. The cell is the basic unit of life which can perform life processes. All cells come from other living cells.