Q.O.D.: What invention revolutionized the discovery of cells and the organelles?
The Discovery of Cells
The invention of the microscope made it possible for scientist to view
and study cells.
Cells- basic units of all living organisms
Cell Theory
1. All living things are made of one or more cells
2. Cells are the basic units of structure and function in all living things.
3. All cells come from other cells.
Microscopes have helped scientists learn more about cells:
Electron Microscopes- allow objects to be magnified up to 500,000X using a beam
of electrons instead of light.
Scanning electron microscope (SEM)- can help scientists see a cells
3-D shape
Transmission electron microscopes (TEM)- allows scientists to see the
structures inside a cell.
Scanning probe microscopes – produce images by tracing surfaces of cells of
structures with a probe.
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All cells contain small structures called organelles.
Each organelle has a specific function in the cell.
Two Major classes of cells:
Prokaryotic cell
Lacks a nucleus and most other organelles
 Ex. Archaea and Bacteria
Eukaryotic cell
Has a nucleus surrounded by membrane-bound
organelles
 Ex. Protists, plants, fungi, and animals.
 Hint: when trying to figure out what type
of cells you have just remember :YOU are
Eukaryotic.