1. What does the cell unit include?
Cell membrane – structure, diffusion and osmosis
Cell signaling and the extracellular matrix
Cell division – mitosis
Cell theory
Why are cells small?
Microscopes & magnification
Stem cells & differentiation
Prokaryotic cells – structure and function
Eukaryotic cells – structure and function

2. Outline the cell theory
All living things are made of cells.
Cells are the smallest unit of life.
Existing cells have come from other cells.

5. Discuss evidence for the cell theory
What follows is a historical perspective on how the cell theory developed

6. What level of complexity is necessary for life?
Aristotle (384 – 322BC)
Organised material (living)
Unorganised material (non-living)
Heterogeneous (organs)
Homogeneous (tissues)
Matter
© 2010 Paul Billiet ODWS

8. What level of complexity is necessary for life?
17th century scientists discovered tissues were made of cells (Hooke 1665 and Leeuwenhoek 1677)
Image Credit Cork cells
© 2010 Paul Billiet ODWS

9. Cells
18th and 19th century scientists showed that tissues were made of cells
The cells of a particular tissue had a common structure.
Image Credit Liver cells

18. THE CELL THEORY
Matthias Schleiden (1838) & Theodor Schwann (1839) “The cell is the basic unit of living tissue”
The cell is the smallest unit that can show all the characteristics of life
Organelles requires cooperation of other organelles for successful function
© 2010 Paul Billiet ODWS

20. « Omnis cellula e cellula »
Rudolf Virchow (1858) noted that: “all cells come from pre-existing cells”
Cell division – mitosis or binary fission
Suggests that cells have a common ancestor and therefore all organisms are related
Image Credit Cell division

21. 9 life processes = MRRREGNTS
State that unicellular organisms carry out all the functions of life
9 life processes = MRRREGNTS
Name and briefly explain:
Nutrition
Metabolism
Growth
Response
Excretion
Homeostasis
Reproduction

24. Compare the relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using the appropriate SI unit – Interesting but not required in new syllabus
SI = ???
1 nm = ?
1 m = ?

26. Molecules of biological significance are around 1 nm in size where as the cell membrane is about ten times thicker at 10nm.
Whereas a virus is ten times larger again at around 100nm.
Whereas a bacteria is ten times larger again at around 1 um.
Whereas a eukaryotic animal cell is ten times larger again at around 10 um.
Whereas a eukaryotic plant cell is ten times larger again at around 100 um.
Read through notepacket to see a good description on how to compare cell sizes with each other….

27. Calculate the linear magnification of drawings and the actual size of specimens in images of known magnification

56. Growing cells
1µm
2µm
3µm
4µm
5µm
6µm
© 2010 Paul Billiet ODWS

59. Surface Area:Volume Ratio
© 2010 Paul Billiet ODWS