1. CELLS

2. Who? What? When?
1665, Robert Hooke – looking at cork under a microscope saw tiny boxes like “rooms” and called them cells. (plants and fungi)
1673, Anton van Leeuwenhoek – looking at pond scum saw tiny moving creatures and called them animalcules. Also saw bacteria, blood, and yeast.
Mid 1800’s other scientists added new discoveries and developed the “Cell Theory”
Schleiden (plants), Schwann (animals), Virchow (cell reproduction)

3. The Cell Theory: All living things are made of one or more cells.
2. Cells are the basic units of life.
3. Cells come from other cells.

4. What’s in a cell?
Cell Membrane – the barrier around the cell that protects it and controls what goes into and out of the cell
Organelles – small structures that carry out specific duties for that cell
Nucleus, mitochondria, chloroplasts, ribosomes
DNA – genetic information that tells the cell what, when, and how to do the things it does (like a road map for life)
Cytoplasm – the fluid in which the organelles and other chemicals are “floating around”

5. 2 Types of Cells
1. Prokaryotes - cells with no nucleus or organelles with membranes. Bacteria and blue-green bacteria are prokaryotic cells. (*smallest cells)

6. 2. Eukaryotes - cells that contain a nucleus and organelles surrounded by a membrane. The cells of protozoa, algae, fungi, plants, and animals are eukaryotic cells. (*larger and more complex)
Plant Cell Animal Cell

7. Prokaryotic vs. Eukaryotic
No nucleus
No membrane-covered organelles
Circular DNA
Bacteria
Nucleus
Membrane-covered organelles
Linear DNA
All other cells

8. A whale is much larger than a pea. Which has cells that are larger?

9. Cell Size More surface area = more materials pass in and out!!
That’s a GOOD thing!!

10. Plant Cell