3.1 The Cell Theory
KEY CONCEPTS
1. Who were the Scientists that
contributed to the cell theory?
2. What are the parts of the cell
theory?
3. What are the 2 types of cells?
VOCABULARY
• PROKARYOTE
• EUKARYOTE
Robert Hooke (1635-1703)
• English scientist.
• Developed the first compound microscope.
Robert Hooke – Discovered CELLS
• In 1665, he used
his microscope to
look at cork cells.
• Hooke coined the
term “cell”
– What he saw under
the microscope
reminded him of the
living quarters of
the monks (cells).
Anton van Leeuwenhoek
(1632-1723)
• Dutch curtain maker who
ground lenses as a hobby.
• Improved and perfected the
microscope.
• The first to observe living cells
- (blood cells and bacteria
from his teeth.)
Mathias Schleiden (1804-1881)
• German Botanist
• Observed that all plants are made up of
cells.
Theodor Schwann (1810-1882)
• German Zoologist
• Observed that all animals are made up of
cells.
Rudolf Virchow (1821-1902)
• German Doctor
• The first to observe
cells reproduce.
• Deduced that
animal cells come
only from animals,
plant cells come
only from plants.
The Cell Theory
The observations of these scientists led to the
cell theory.
The modern cell theory has 3 parts:
a. Cells are the basic units of life
b. All living things are made of one or
more cells.
c. All cells come from preexisting cells.
Organization of Life
• Organisms can be
uni-cellular (singlecelled) or
multicellular.
• Multicellular
organisms are
organized into
complex
structures.
• Multicellular organisms:
have specialized cells
to perform a single
function.
– Ex. Red blood cells
carry oxygen; muscle
cells provide movement
Molecules
COMBINE TO FORM
Cells
Make up
Red blood cells
Tissues
Make up
Cardiac muscle
Organs
Make up
Heart
Systems
Make up
Circulatory System
Organisms
POPULATIONS
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Types of Cells
• Prokaryotic cells – the first cells that have
little internal structure. DO NOT HAVE A
NUCLEUS
• Eukaryotic cells – evolved from prokaryotic
cells & have “mini organs called organelles.”
– HAVE A NUCLEUS
Organelles – structures in the cell responsible
for carrying out specific functions. “cell organs,”
Prokaryotic Cells
• Prokaryotic cells are always single-celled
organisms.
– Ex. Bacteria
• Very simple structure – cell wall and
membrane surrounding cytoplasm.
Eukaryotic Cells
• Eukaryotic cells:
Can be singlecelled or
multicellular
organisms.
Ex. Algae (single)
or plants (multi)
Eukaryotic Cells
• Structure divided into 3 areas: NUCLEUS,
CYTOPLASM, AND CELL MEMBRANE.
• Eukaryotic cells have numerous
organelles