1. Discovery of Cells

2. First to View Cells
In 1665, Robert Hooke used a microscope to examine a thin slice of cork
What he saw looked like small boxes so he called them “cells”

3. Anton van Leeuwenhoek
In 1673, Leeuwenhoek was first to view organisms under a microscope
He looked at pond water & plaque he scraped from his teeth

4. Development of Light Microscope
Leeuwenhoek was the first scientist to describe living cells as seen through a simple microscope
Simple Light Microscope - One lens and uses natural light
Compound Light Microscope - More than one lens to magnify
Magnifies up to 1500 times.

5. CELL THEORY All living things are made of cells
NEED TO KNOW!!!
NEED TO KNOW!!!
All living things are made of cells
Cells are the basic unit of structure and function in an organism (basic unit of life)
Cells come from the reproduction of existing cells (cell division)

6. Cell Classification Prokaryotes Eukaryotes
NO Membrane bound organelles
NO nucleus
Bacteria
Eukaryotes
Most cells
True nucleus
Membrane bound organelles
Plants, fungi, animals

7. Prokaryotes Simplest type of cell
Lack a nucleus or membrane bound organelles
Single, circular chromosome
Bacteria and Archaebacteria

8. Prokaryotes DNA located in the center Cell membrane AND cell wall
Ribosomes to make proteins
May have cilia/pilli/flagella to aid in movement

9. Eukaryotes HAVE a nucleus and membrane bound organelles
Protists, fungi, plants, and animals
Larger and more complex type of cells

10. Eukaryotic Cell Nucleus that contains DNA Cell membrane
Specialized organelles
Where chemical reactions occur

11. Number of Cells Unicellular Organisms Multicellular Organisms
Organism is only one single cell
Multicellular Organisms
Complex organisms with cells organized into tissues, organs, systems

12. Looking at Cells A cell’s shape reflects its function
Can be long and flat, branched, round, etc
Cell size is limited by the cell’s surface area to volume ratio
The larger the cell, the more nutrients it needs and waste it produces