1. The Cell Theory

2. What was science like before the invention of the microscope?
Essential Question #1
What was science like before the invention of the microscope?

3. What Science Believed…
In the 16th century doctors rarely touched their patients. They just studied their excreta (bodily fluids) instead.
Common Practices:
Blood letting
Leeches
Reading fluids

4. Medical Wisdom of the 16th Century
God implanted the soul in the embryo forty days after conception. The soul controlled growth and nutrition, sensation and motion, and all rational activity.
Women were nothing more than imperfect versions of men.
Diagnoses could be made from the nature of excrement, and tint of skin
The liver created blood, which was used by the brain to create invisible nervous spirits which flowed through the nervous system and were vectors of sensation and motion. 

5. Beliefs About Life… Scientists believed in Spontaneous Generation.
Example: Scientists believed that maggots come from rotting meat and mice come from grain.

6. The Meat & Maggot Experiment
What We Know Now…
Life can only come from other living things!
Francesco Redi designed a brilliant controlled experiment.
The Meat & Maggot Experiment

8. How did the invention of the microscope change science?
Essential Question #2
How did the invention of the microscope change science?

9. Microscope History
1590- Zacharias Jenssen: built the first microscope.

10. Microscopes Continued
Robert Hooke: made improvements to Jenssen’s microscope.
Why is this important?

11. Hooke and Cells!
Hooke came up with the term “Cell” after looking at the cell walls of plants.
The box-like cells of cork reminded Hooke of the cells of a monastery.

12. Can You See What Hooke Saw?

13. 1675: Antony van Leeuwenhoek
Leeuwenhoek: constructed a simple microscope that could magnify objects as much as 270 times.
He was the first to see…?

15. What are the components of the Cell Theory?
Essential Question #3
What are the components of the Cell Theory?

16. The Cell Theory All living things are composed of cells.
Cells are the basic unit of life (structure and function).
Cells come from preexisting cells.

17. You Already Knew… Plants and animals are made up of cells.
It is one of the five characteristics of life:
All living things are made up of cells.
All living things have cellular organization.

18. Science Didn’t Until…
Matthias Schleiden: concluded that all plants are composed of cells.
Theodore Schwann: concluded that all animals are composed of cells.

19. Schleiden and Plants
When you weed your garden, you are uprooting plants from the soil.
Schleiden was the first scientists to say that those plants are made up of cells.

20. Schleiden is Weedin’

21. Schwann and Animals
Schwann was the first scientists to say that all animals are composed of at least one cell.

22. Schwann’s Swans

23. Together…
All living things
are composed
of cells!

24. Brief History of Cells

25. Quick Quiz
Put these items in order in terms of which came first in the scientific study of living things:
____ DNA
____ Light Microscope
____ Electron Microscope
____ Cell Theory
____ Discovery of Cells

26. Quiz Answer
Put these items in order in terms of which came first in the scientific study of living things:
1. Light Microscope
2. Discovery of Cells
3. Cell Theory
4. DNA
5. Electron Microscope