Cells are the basic unit of life.
All living organisms are made of cells whether they are
one cell) or multi-cellular (containing many cells).An example of a unicellular organism is bacteria, and an example of a
multi-cellular organism is a human.
All cells vary in size, but their shape is directed to their function. An example
of this is a muscle or nerve cell, which are long in shape.
Discoverers of Cells:
1665- Robert Hooke published Micrographia, which contained drawings of cork cells and other objects he had observed
using the microscope. He called the chambers cells, because they reminded him of the empty rooms in the monastery.
1670- Anton van Leewonhoek modified the microscope and began to examin new materials.
1838- Schleiden concluded that all plants are made of cells.
1839- Schwann concluded that all living things are made of cells.
1855- Virchow infered that all new cells come from existing cells.
The Cell Theory: (3 parts)
- Cells are the basic unit of life
- Are organisms are made of one or more cells
- All cells arise from existing cells