1. Introduction to the Cell Theory

2. What is a Cell?? Cells – the basic unit of life
Organelles - small structures inside a cell with specific functions

3. Ostrich Egg

4. 1665 – Robert Hooke Coined the term "cells”. Observed cells in cork.
Cork Cells

5. 1673- Anton van Leeuwenhoek
Created a more improved microscope

6. Robert Brown
-noticed that pollen grains in water jiggled around called “Brownian motion”
-discovered the nucleus
Nucleus
Human Cheek Cell

7. A botanist who concluded that all plants are made of cells.
Matthias Schleiden
A botanist who concluded that all plants are made of cells.
Typical Plant Cell

8. 1839 - Theodor Schwann A zoologist who concluded that all animals
are made of cells.
Nerve Cells

9. 1855 - Rudolph Virchow A physician who did
research on cancer cells and concluded
“Omnis cellula e cellula”.
“All cells are from other
pre-existing cells.”

10. The Cell Theory
1. All living things are composed of one or more cells.
2. Cells are the basic units of structure and function in an organism.
3. Cells come only from existing cells.

11. All cells have…… Plasma (cell) Membrane Nucleus (eukaryotes only)
Cytoplasm (an area)
Organelles (structures with
specialized functions)

12. Cell Types
Prokaryotes- simple cells that do not have internal membranes
example = bacteria
Eukaryotes- more complex cells that do have internal, membrane-bound structures
examples = plants and animals

13. Prokaryotic Vs Eukaryotic

14. Eukaryotic Organisms: include protists, fungi, plants and animals
Timeline
Prokaryotic
Organisms:
First appeared 3.0 BYA
include bacteria
and cyanobacteria
Eukaryotic Organisms:
First appeared 2.0 BYA
include protists, fungi, plants and animals

15. Key Differences: Eukaryotes Prokaryotes
Have a nucleus and other membrane bounded structures.
Have large ribosomes
DNA is organized into chromosomes
Prokaryotes
Lack a nucleus and other membrane bounded structures.
Have small ribosomes
DNA is not organized into chromosomes

16. Examples
Prokaryotic
Eukaryotic
Nucleus

17. Eukaryotic
Prokaryotic