1. Thursday, October 14, 2010 (10/14/10)
DSQ, page 23 (add an extra piece of paper to page 23 if you need more room)
Q: What is a theory?
A: A theory is a well tested explanation for a wide range of observations

2. Agenda Reminders: Reflections (4) are due tomorrow (Friday).
Test (Intelligence, Mindset, Brain) tomorrow (Friday)
Notebook Check on Wednesday (10/20)
Test (Living things) retake on Wednesday (10/20)
Continue Power Point Presentation on Cells and the Cell Theory. Student notes go on page 37.
The Cell Theory Timeline (will go on page 36).

3. Look at the skin on your arm…
…can you see cells?

4. Cells: The Smallest Unit of Life
Bacteria (Purple)
“INVADER”
White Blood Cell (Yellow)
“SOLDIER CELL”
Harmful bacteria can invade your body and make you sick. But you have white blood cells that come to the rescue. Here there is a white blood cell (yellow) that is attacking bacteria (purple). Red disks are red blood cells.
Red Blood Cell

5. Video: Introduction to Cells

6. What are Cells? A cell is the smallest unit of life.
You are made of billions of cells.
There are many types of cells.
Each cell has a special structure and function.

7. Some examples of cells…
Skin Cells
Human Bone Cells
Heart Muscle Cells
Red Blood Cells

8. All Cells… Share the characteristics of all living things:
Sense and respond to change.
Reproduce.
Have DNA.
Use Energy.
Grow and develop.

9. Cells are so small that you need to use a microscope to see them.
Microscopes were first invented in the 1600’s.
Before then, nobody knew what cells looked like.

10. Hans and Zacharias Janssen (Dutch)
Dutch lens grinders
Around 1590, Hans and Zacharias Janssen (father and son) created the first compound microscope.

11. Robert Hooke (from England)
Born 1635
Very well educated
English Physicist
Invented the Hooke Microscope (1670)

12. Robert Hooke
In 1665, he took a very thin piece of cork…

13. …and put it under his microscope.
He saw something that looked like little boxes
He called them “Cells”, which means “little rooms”
In 1665, he was the first person to make detailed sketches of cells.

14. Hooke also looked at… other plants and fungi
he kept seeing the same kind of box-like cells
Elodea Leaf Cells
Onion Cells
Spring Leaf Cells

15. Anton van Leeuwenhoek (from Holland)
He loved lenses! And he knew about Hooke’s cork cells!
Born in 1632 in Holland
Had a drapery business
Not very educated – only went to school until age16
He combined lenses together and built his own microscope– it was a very powerful magnifying glass!

16. In 1673, he collected some pond water, blood, and scrapings from his teeth,
and put them under his microscope.

17. And he saw…
Animacules (“little animals” - single celled organisms – today we call them protists)
Pond Water
Blood
Blood Cells
They all look similar…in a way.
Teeth Scraping
Bacteria

18. About 200 years later… Matthias Schleiden (from Germany)
Studied plants (Botanist)
1838 – “All plant parts
are made of cells”.
Theodor Schwann
(from Germany)
Studied animals (Physiologist)
1839 – “All animal tissues are made of cells”.
Rudolf Virchow (from Germany)
Studied medicine and disease (Physician)
1858 – “Cells can form only from other cells”

19. Together, they came up with a theory
Together, they came up with a theory. Theory : An idea that explains a whole bunch of related observations. What observations did these guys make? No matter what living organism they looked at, they saw cells.

20. The Cell Theory 1. All organisms are made of one or more cells. 2
The Cell Theory 1. All organisms are made of one or more cells. 2. All cells come from existing cells. 3. The cell is the basic unit of all living things.
The scientific advances made by all these gentlemen led to the formation of the cell theory. Scientific discovery is sometimes a long process.

22. Why is the Cell Theory Important?
It is the foundation of biology.
Every living organism has the cell as its basic unit.
It holds true for all living things, no matter how big or small, or how simple or complex.

23. All living things have cells!!

24. Video – Through the Lens

25. The Cell Theory Timeline
Add important dates, people, and events to your timeline.
Drawings and sketches add interest.
DON’T FORGET THE BOX ON THE BOTTOM!!!

26. (on page 37, behind notes) Vocabulary
Word
Formal Definition
In Your Own Words
Picture or Sketch
Organism
Any living thing
Cell
The basic unit of all life forms
Theory
A well-tested explanation for a wide range of observations
Cell Theory
Explains the relationship between cells and all living organisms