Section 8.1  Cell Site

The Discovery of Cells

Section 8.1

pages 190-195

History of the Cell Theory

How do we view cells?

What did the discovery of cells have to do with human history?

What is the cell theory?

Who discovered cells?

Vocabulary Words

Cell

Compound Light Microscope

Cell Theory

Electron Microscope

Prokaryote

Eukaryote

Organelle

Nucleus

Microscopes

Simple Vs. Compound Microscopes

Light Microscopes

Scanning Electron Microscopes (SEM)

Transmission Electron Microscopes (TEM)

People Who Studied Cells

Anton van Leeuwenhoek
1600’s
Used a high power magnifying glass

Robert Hooke
1665
Used a crude compound microscope to observe the cells in cork (from an oak tree)

People Who Studied Cells

Matthias Schleiden
1830
Observed various plant cells

Thomas Schwann
1830
Observed various animal cells

These two and other scientists developed the cell theory during the 1800’s

The Cell Theory

1. All organisms are composed of one or more cells.

2. The cell is the basic unit of organization of organisms.

3. All cells come from preexisting cells.

Two Basic Types of Cells

Prokaryotic

Lack internal structures surrounded by a membrane

no true nucleus

Eukaryotic

Contains internal structures surrounded by a membrane

have a true nucleus

Questions

Why are microscopes necessary for the study of cells?

Compare SEM and TEM microscopes.

Compare prokaryotic and eukaryotic cells.

If a microscope has a 15x eyepiece and three lenses of 6x, 40x, and 95x what are the three magnification powers?