1. Unit 3: Cytology
The Study of CELLS.

2. Definition:
The smallest unit of structure and function of life capable of exhibiting all characteristics of life.

3. The Cell Theory All living things have at least 1 cell.
Cells are the basic units of structure and function in an organism.
Cells come only from other cells – replaced the idea of Spontaneous Generation.

4. The Myth = Spontaneous Generation
The idea that some living things
originated from unrelated and
sometimes nonliving entities.

7. Theory of BIOGENESIS = life comes only from preexisting life.
*Officially rejected after Louis Pasteur’s experiment in 1859
*Pasteur developed the
Theory of BIOGENESIS = life comes only from preexisting life.

8. Types of Cells a. Prokaryotic * Unicellular organisms only=
Kingdom Archaebacteria
Kingdom Eubacteria
Lack membrane-bound organelles
* Have a cell (plasma) membrane, DNA, RNA, Cytoplasm, cytoskeleton, and ribosomes

9. PROKARYOTIC CELLS

10. b. Eukaryotic
* In Unicellular and multicellular
organisms (All Kingdoms =4 of Domain Eukarya)
* Have membrane-bound organelles along with a cell membrane, DNA in a nucleus, RNA, cytoplasm, a cytoskeleton, and ribosomes.

11. EUKARYOTIC CELLS

12. Cell Differentiation
*All organisms begin life as a single cell. *In multicellular organisms, cells divide and become specialized to perform specific functions for the organism.
Fat Cells

13. *Muscle Cells

14. *Nerve Cell

15. *Blood Cells
RED BLOOD CELLS
A White Blood Cell Among Red

16. *Reproductive Cells
Sperm Cells
Egg Cell

17. Cells of the lungs = Alveoli

18. 1. Compound Light Microscopes
Tools of Cytology :
1. Compound Light Microscopes
*optic microscope - * 2 lenses
* Visible light must pass through the
specimen
*highest possible magnification = 2000X.

20. 2. Electron Microscopes
*uses a beam of electrons to create a highly-magnified image.
*magnify up to 1 million times larger than actual size.

21. Electron Microscopes

25. Electron Microscope E. coli Bacterial Cells

26. Electron Microscope Image of DNA

27. Electron Microscope Images of Dermodex Mites

29. Electron Microscope Image of Pollen

31. 5. Cell Structures and Functions
See Cell Parts Chart!

32. STOP

33. Who invented the first compound light microscope and when?
2. Why is Robert Hooke a significant
individual in biology? When did he do his
work?
3. Why is Anton van Leeuwenhoek
a significant individual in biology? When
did he do his work?
What is the Cell Theory and what does it state?
What is Cell Differentiation?

34. Unit 3 CYTOLOGY History of Cytology
a Dutch spectacle-makers, the Janssens = first compound light microscope.

35. b. Robert Hooke
In 1665, Robert Hooke observed cork using a primitive microscope.
Called the compartments he saw “CELLS” = 1st to use the term.

36. Cork cells as diagrammed by Robert Hooke

37. Photo of Actual Cork Cells 400X

38. c. Anton Van Leeuwenhoek
* created his own microscope to observe water and tissue samples.
“Father of Microbiology”= First to observe/create figures of many living cells of organisms previously unseen by the unaided eye.

39. Van Leeuwenhoek

41. Other Notable Scientists:
Schleiden – all plants have cells
Schwann – all animals have cells
Virchow – cells come only from other cells

43. *first proposed by Aristotle
*first tested by Francesco Redi (1668)

44. Francesco Redi
In one experiment, Redi took six jars, which he divided in two groups of three: in the first jar of each group, he put an unknown object; in the second, a dead fish; in the last, a raw chunk of veal. Redi took the first group of three, and covered the tops with fine gauze so that only air could get into it. He left the other group of jars open. After several days, he saw maggots appear on the objects in the open jars, on which flies had been able to land, but not in the gauze-covered jars.

45. Crash Course - Cells
Eukaryopolis - The City of Animal Cells: Crash Course Biology #4
Plant cells

46. Bozeman biology
A Tour of the Cell