1. The History and Theory of Cells
Ch. 3 Section 1

2. Cell
A cell is the smallest unit that can perform all the processes necessary for life.
Cells were not discovered until microscopes were invented in the mid 1600s.

3. Cells Timeline Cell Size 1839 Animal tissue made of cells 1952 1997
DNA is
hereditary material
Dolly is cloned
1665
1858
1673
1838
1873
1956
Protein production in ribosomes
Mitosis
Observed
1831
Nucleus Discovered

4. Robert Hooke The first person to describe cells.
First looked at cork cells in
He named them cells, which means “little boxes” in latin.
He mainly studied plant cells because they were easier to see. Plant cells have cell walls.
He thought animals did not have cells.
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Timeline

5. Anton van Leeuwenhoek (LAY vuhn HOOK)
Dutch man that made his own microscope in 1673.
Viewed single-celled organisms we now call protists and bacteria.
Studied different blood cells
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Timeline

6. Cell Theory
In 1838, Matthias Schleiden studied plants. He concluded that all animal tissues were made of cells.
He wrote the first two parts of the cell theory.
In 1858, Rudolf Virchow added the third part of the cell theory.
Cell Theory
All organisms are made of one or more cells.
The cell is the basic unit of all living things.
All cells come from existing cells.
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Timeline

7. Cell Size
Most cells are very small. There are a few exceptions; chicken and ostrich eggs.
These cells are large because they do not need to take in nutrients.

8. Surface area-to-volume ratio= Surface area volume
Cell Size Continued
Cells must take in food and get rid of wastes through their outer surface.
As cells get larger they need more food and produce more waste.
The cell’s volume grows faster than its surface area.
Surface area-to-volume ratio= Surface area volume

9. Prokaryotes
A prokaryote is a single-celled organism that does not have a nucleus or membrane-bound organelles.

10. Archaea
There are three types of archaea: 1. Methane-Making: Live in deep ocean near volcanic vents 2. Heat-Loving 3. Salt-Loving Extremophiles (includes heat and salt loving) line in places where conditions are considered extreme like, hot springs and salty water.

11. Eukaryotes
A eukaryote is an organism that is made of many eukaryotic cells. These organisms are multi-cellular.
Eukaryotic cells are the largest type of cells.
These cells have a nucleus.

12. Labeling your Prokaryote
Cell Wall- Green
Cell Membrane- blue
Cytoplasm- yellow
Nucleoid (DNA)- red
Flagella- orange
Pili- purple
Ribosomes- black