3. Life Is Cellular

4. The Cell Theory Early 1600’s – Two useful instruments were constructed
Telescope
Microscope

5. Anton van Leeuwenhoek
One of the first people to use a microscope to study nature.

6. Anton van Leeuwenhoek
Using only a single powerful lens, he crafted instruments that could produce magnified images of very small objects.

7. Anton van Leeuwenhoek
His simple microscope enabled him to see things that no one had ever seen before.
First person to see tiny living organisms in a drop of water. (1674)

8. Robert Hooke

9. Robert Hooke 1665 – English Physicist
Used one of the first light microscopes to look at thin slices of plant tissues.

10. Robert Hooke One of these, a slice of cork.
Under the microscope the cork seemed to be made of thousands of tiny chambers.
Hooke called these chambers “cells”, because they reminded him of a monastery's tiny rooms aka cells.

13. Cork Cells

14. Search For Cells In Other Living Things
1838 – Matthias Schleiden
All plants are made of cells
1839 – Theodore Schwann
All animals are made of cells
1855 – Rudolf Virchow
Studied cell reproduction.
“Where a cell exists, there must have been a preexisting cell…”

15. New Discoveries CELL THEORY
The discoveries of these and other biologists are summarized in one of the fundamental concepts of biology.
CELL THEORY

16. Cell Theory All living things are composed of cells.
Cell are the basic units of structure and function in living things.
New cells are produced from existing cells.

17. Prokaryotes and Eukaryotes
Biologists divide cells into two categories:
Prokaryotes and Eukaryotes

18. Compare and Contrast Eukaryotes Smaller and Simpler
Prokaryotes
Smaller and Simpler
Have Cell Membrane and Cytoplasm
No Nuclei
Examples (Bacteria)
Eukaryotes
Larger and More Complex
Have Cell Membrane, Cytoplasm, Nucleus, Dozens of Specialized Structures (Organelles)
Examples: All Plants, Animals, and Fungi, and Many Microorganisms
Some Live Solitary Lives