History of Cells

1
History of Cells

• Timeline of scientists and their discoveries

2
1) Anton von Leeuwenhoek

• 1600s
• Dutch businessman
• Invented 1st simple light microscope

3
Anton von Leeuwenhoek (cont)

• Observed tiny organisms in pond water
• Organisms were nicknamed wee beasties

4
2) ROBERT HOOKE

• 1665
• English physicist
• Observed flowers, insects, and plant tissue

5
ROBERT HOOKE (cont)

• Observed thin slices of cork (oak tree)
• Coined the term cell based on the rooms in a
  monastary

6
3) ROBERT BROWN

• 1833
• Observed plant cells under the microscope

7
ROBERT BROWN (cont)

• Observed a dark structure inside each cell and
  coined the term nucleus

8
4) MATTHIAS SCHLEIDEN

• 1838
• German botanist scientist who studies plants
• Concluded all plants are made up of cells

9
5) THEODORE SCHWANN

• 1839
• German biologist
• Concluded all animals are made of cells

10
6) RUDOLF VIRCHOW

• 1855
• German Physician
• Studied cell reproduction
• Concluded all cells arise from preexisting cells

11
The cell theory

• 1. All living things are composed of cells
• 2. Cells are the basic unit of structure and
  function in living things.
• 3. All cells arise from preexisting cells.

12
Introduction to Cells

• Chapter 6

13
Levels of Organization

• All living organisms can be studied on many
  levels
• From smallest to largest they are
• Chemical (atoms molecules)
• Cells
• Tissues
• Organs
• Organ Systems
• Whole Organism

14
Basic Structure of Cells

• All cells have a cell membrane and cytoplasm
• Cell Membrane thin, flexible barrier around cell
• Composed of lipids and proteins
• Cytoplasm jelly-like material inside the cell
• All cells contain organelles
• Organelles small structures that perform
  different functions within a cell

15
Prokaryotic Cells

• Do NOT have a nucleus
• Instead a small ring of DNA is free-floating in
  center of cell
• Organelles do NOT have a membrane
• i.e. bacteria (very simple organisms)

16
Eukaryotic Cells

• Contain a nucleus
• Organelles are membrane-bound
• Much more complex
• i.e. plants, animals, fungi