1. Write this heading: Cell Theory Timeline

2. Write a heading in your notebook…
The Cell Theory 1. 2. 3.

3. Cell Theory – write in your notebook
1. All living things are made of cells.
2. Cells are the basic units of structure and function in living things. (structure = form; function = purpose)
3. Living cells only come from other living cells.

4. Read each box. Concept #3- All polar bears
cell came from a single living
cell. They divide and they
grow to replace old dead cells!
Concept #1- A polar
bear is made up of
many cells!
Concept #2- Different cells in
a polar bears body does
different jobs. Example: Fat
cells provide insulation and
energy, while red blood cells
carry oxygen.

5. Controlled Experiments were born
Read: Cell Theory Concept #3: Living cells only come from other living cells. People believed that maggots mysteriously appeared on decaying meat. Some thought that the meat actually created maggots.
Redi placed meat in two identical jars. He left one jar uncovered and allowed flies to come into contact with the meat. He covered the other jar with a cheese cloth or other cloth that allowed air to pass through. Contact with the air allowed the meat to decay, just as the other would.
After a short period of time Redi observed maggots (fly larvae) on the decaying meat of the open jar. There were no maggots on the meat in the covered jar
Redi concluded that the flies laid eggs on the meat in the open jar which caused the maggots
Controlled Experiments were born

6. Taking Notes In order to complete your timeline notes…
Write notes about the following scientists
1 Aristotle
2 Zacharias and Hans Jansen
3 Robert Hooke
4 Anton van Leeuwenhoek
5 Matthias Schleiden
6 Theodor Schwann
7 Rudolph Virchow
Write down their name, date, and the main ideas of what they did.

7. Aristotle 334 B.C. Aristotle observed nature directly.
He classified all known organisms as either plants or animals.

8. Hans & Zacharias Janssen
In 1595
Hans & Zacharias Jansen produced the first compound microscope by lining up 2 lenses.

9. Robert Hooke
1665
Robert Hooke observed a microoganism, the microfungus Mucor (cork cells) through a compound microscope, which reveals empty cells.
He is the first to call the spaces in the cork “cells” which means little rooms.

10. Anton van Leeuwenhoek
1675
Anton van Leeuwenhoek observed living cells (bacteria) through a simple microscope.

11. Matthias Schleiden
1838
Matthias Schleiden discovered that plants were made of cells.

12. Theodor Schwann
1839
Theodor Schwann states “all animals are made of cells.”

13. William Henry Perkin
1856
William Henry Perkin develops an intense purple dye, which is used to stain microscope slides, shows more details.

14. Rudolph Virchow 1858 Rudolph Virchow states…
“Cells are the last link in a great chain that forms tissues, organs, systems, and individuals. Where a cell exists, there must have been a preexisting cell.”
Cells can only arise from pre-existing cells

15. Create a timeline!
Use your notes from today and your handout on the Cell Theory Timeline.
Write dates on the timeline, and major events above and below it.
Include a brief detail of what happened, and a picture to help remember it.