1. The History of Cell Biology

2. Objectives
Name the scientists who first observed living and nonliving cells
Summarize the research that led to the development of the cell theory
State the three principles of the cell theory
Explain why the cell is considered to be the basic unit of life

3. Important Vocabulary Cell Light microscope Nucleus Cytoplasm
Cell theory

4. With a Partner
Determine which of the following is made of cells and be ready to defend your answers:
Baseball bat Dandelion
Glass Brick
Stone Beetle
Cork Gecko

5. Discovery of the Cell
All living things are made up of one or more cells
A cell is the smallest unit of life
Starting in the 17th century, scientists were able to use microscopes to study the minuet world around them

6. Robert Hooke Was an English scientist
In 1665, he was the first person to see and name cells
He did this by using a light microscope,
which is an instrument that uses optical lenses to magnify objects by bending light rays
He described cells as “little boxes”
But why did he call them cells?

7. Hooke
The cork cells were empty Why?

8. Anton van Leeuwenhoek
Was a Dutch trader who dabbled in natural science
In 1675, he was the first person to observe living cells
Leeuwenhoek made microscopes that were simple and tiny
He ground lenses so precisely that the magnification was 10 times that of Hooke’s instruments

9. What Leeuwenhoek Saw: We call them protists today
Vorticella
Spirogyra
We call them protists today
Leeuwenhoek call them _______________
animalcules

10. Robert Brown Was a Scottish botanist
In 1833, he discovered a central structure within cells
This structure became known as the ___________
nucleus

11. Felix Dujardin Was a French biologist
In 1835, he first identified protoplasm in living cells
Protoplasm is also known as _______________
cytoplasm

12. Matthias Schleiden Was a German botanist
In 1838, he proposed the hypothesis that all plants are made of cells

13. Theodor Schwann Was also a German biologist
In 1839, he proposed the hypothesis that all animals are made of cells.

14. Rudolf Virchow Was a German pathologist
In 1855, he proposed that cells reproduce to form new cells

15. The Cell Theory
From the work of all these scientists the three tenants of the cell theory were developed!

16. ALL LIVING THINGS ARE COMPOSED OF CELLS
Tenant 1
ALL LIVING THINGS ARE COMPOSED OF CELLS

17. CELLS ARE THE BASIC UNITS OF STRUCTURE AND FUNCTION OF LIVING THINGS
Tenant 2
CELLS ARE THE BASIC UNITS OF STRUCTURE AND FUNCTION OF LIVING THINGS
“They’re the building blocks of LIFE!”

18. Tenant 3
NEW CELLS ARE PRODUCED FROM EXISTING CELLS

19. 1665 1827 1855 1857 1897 1996 2004 Hooke observes cork cells
Karl Von Baer discovers the mammalian egg
1855
Virchow adds to the cell theory
1857
Kolliker describes mitochondria in muscle
1897
Golgi discovers the Golgi apparatus in cells
1996
Dolly the sheep is cloned
2004
Tissue engineering is used to grow new skin and bone for transplant