210 likes | 224 Views
Learn about the Cell Theory, which states that all organisms are composed of cells. Explore the experiments that disproved spontaneous generation and the development of the Cell Theory through the invention of the microscope. Discover the differences between prokaryotic and eukaryotic cells and the importance of organelles.
E N D
Chapter 7 Section 1 Discovery of Cells
The Cell Theory • The Cell Theory states that all organisms are composed of similar units of organization called cells.
Before the Cell Theory people believed in spontaneous generation which means living things come from non living thingTwo scientist disproved spontaneous generation.
Francisco Redi proved that macroorganisms do not spontaneously generate People thought that maggots came from meat. • Redi disproved this in a controlled experiment
Pasture proved that microoganisms do not spontaneously generate
Development of Cell Theory • Theodor Schwann and Matthias Schleiden are credited with coming up with the Cell Theory
Schwann • Animal Cells
Schleiden • Plant Cells
The Cell Theory 1. All known living things are made up of cells. 2. The cell is structural & functional unit of all living things.. 3. All cells come from pre-existing cells by division.(No spontaneous generation ).
Microscopes • The Cell Theory would not exist if it wasn’t for the development of the microscope and the work of others.
Janssen • Invented the first compound microscope
Robert Hooke • In 1663 an English scientist, Robert Hook improved Janssen’s invention.
Hooke • Hooke observed cork – the remains of dead tree bark • Coined the word CELL • Derived from the Latin 'cellula' which means small compartment.
Van Leeuwenhoek • Ten years later Anton van Leeuwenhoek used his own single lens microscopes and was the first person to observe bacteria and protozoa.
Leeuwenhoek’s Microscope • Leeuwenhoek microscopes resemble high power magnifying lenses.
Compound Light Microscope • Ocular lens times objective lens give total magnification
Prokaryotic Cells Mainly single celled organisms Eukaryotic Cells Mainly multicellular organisms, although some are single celled (amoeba,algae, yeast) Two Basic Cell Types
Prokaryotic Cell • Prokaryotes have no membrane bound organelles. • Example – bacteria cell
Eukaryotic Cells • Eukaryotes – contain membrane bound organelles • Example – plant and animal cells
Organelles • An organelle is a small specialized structure inside of a cell. • An example of an organelle is the nucleus which controls cell functions.