A
cell is the basic unit of life.
 The
development and enhancement of
microscopes made the observation
and description of microscopic
organisms and living cells possible.
 The
cell is the basic unit of life.
 All living things are made of cells.
 Cells come from pre-existing cells.
 1665
 Looked
at cork under the microscope and
saw tiny empty chambers that he called
cells.
 1674
 Improved
the microscope
 First to see single celled organisms
 1838
 All
plants are made up of cells.
 1839
 All
animals are made up of cells
 1855
 Proposed
that all cells come from existing
cells, completing the cell theory.
2
Types of Cells
Prokaryote
 Eukaryote

 The
simplest life forms
 Unicellular
 Exist in two major forms: eubacteria and
archaebacteria.
 Lack a nucleus and membrane bound
organelles.
 Example: Bacteria
 Eukaryotes
arose
from prokaryotes
and became larger
more complex.
 Eukaryotes contain a
nucleus and
organelles
surrounded by a
membrane.
 Can
be unicellular or multicellular
 Contain a nucleus in which their genetic
material is separated from the rest of the
cell.
 Examples: plants, animals, fungi, and
protists
EXAMPLES
OF
EUKARYOTIC
CELLS
 Robert
Hooke- observed that cork has small
chambers which he called “cells”.
 Anton van Leeuwenheok- helped improved
the first microscope
 Matthais Schleiden- all plants are made up of
cells.
 Theodor Schwann- all animals are made up of
cells.
 Rudolph Virchow- discovered that all cells
come from pre-existing cells.
 Basic
unit of life.
 Cell theory



All living things are composed of cells
Cells are the basic units of structure and function
in living things
New cells are produced from existing cells
 Prokaryotes





Do not contain a nuclei
Smaller and simpler than eukaryotes
Do contain genetic material
Unicellular only
Example: bacteria
 Eukaryotes




Contain a nucleus, which contains their genetic
material
Larger and more complex than prokaryotes
Unicellular and multicellular
Examples: plants, animals, fungi, and protists