Cell Theory

1
Cell Theory

• Cells and Heredity

2
What Hooke Observed

• Robert Hooke observed cork through an early
  microscope.
• He drew the illustration shown on the left.
• He called the individual units cells after the
  monks rooms in a monastery.

Source http//www.ucmp.berkeley.edu/history/hooke
.html
3
Cork Cells

• Compare the photograph of cork cells viewed
  through a modern light microscope to Hookes
  drawing.
• Source http//biology.clc.uc.edu/Fankhauser/Labs/
  Cell_Biology/Cells_Lab/cork_100x_PA021953c.JPG

4
Timeline

• Source http//www.biology.arizona.edu/cell_bio/t
  utorials/cells/cells3.html

5
Plants are composed of cells.

• Matthias Jakob Schleiden (1804 -1881)

6
Plant Cell Light Microscope

• Source http//www.umanitoba.ca/faculties/science/
  biological_sciences/lab3/images/lightplt.jpeg

7
Plant Cell EM Image

• Source http//www.umanitoba.ca/faculties/science
  /biological_sciences/lab3/images/eukplant3.jpeg

8
Animals are composed of cells.

• Theodor Schwann (1810-1882

9
Animal Cell Light Image

• Source http//www.umanitoba.ca/faculties/science/
  biological_sciences/lab3/images/lightani.jpeg

10
Animal Cell EM Image

• Source http//www.umanitoba.ca/faculties/science
  /biological_sciences/lab3/images/eukanimal5.jpeg

11
Animal Tissue

• Source http//faculty.clintoncc.suny.edu/faculty
  /Michael.Gregory/files/Bio20102/Bio2010220Labor
  atory/animal20tissues/img001.jpg

12
Plant Tissue
What two structures do plant cells have that
animal cells lack?

• Source http//ccollege.hccs.cc.tx.us/instru/Biolo
  gy/AllStudyPages/Cells/Images/ELODIA400_labeled.jp
  g

13
The cell is the basic unit of life.

• Anton van Leeuwenhoek (1632-1723)

14
Single Cell Life Form

• Source http//www.umanitoba.ca/faculties/science
  /biological_sciences/lab3/images/bacillus.gif

15
Cells come from cells.

• Rudolf Ludwig Karl Virchow (1821 -
  1902)

16
Plant Cell Division

• Source http//www.extension.iastate.edu/nutritio
  n/supplements/folic_acid.php

17
Animal Cell Division

• Source http//www.luc.edu/depts/biology/dev/urch
  indv.jpg

18
Single-Cell Organism

• Source http//ebiomedia.com/gall/classics/Parame
  cium/images/para4.jpg

19
Cell Theory

• What are all life forms made of?
• Where do new cells come from?
• What is the smallest form of life?

20
Cell Theory

• All life forms are made from one or more cells.
• Cells only arise from pre-existing cells.
• The cell is the smallest form of life.

21
Chromosomes

• Source http//www.millerandlevine.com/chapter/11/
  chromosomes.jpg

22
DNA

• Source http//www.epa.gov/maia/html/biodiversity
  .html

23
Discovery of DNA

• What can be added to the Cell Theory as the
  result of the discovery of DNA?

24
Modern Cell Theory

• 1. All organisms are made up of cells.
• 2. New cells are always produced from
  pre-existing cells.
• 3. The cell is a structural and functional unit
  of all living things.
• 4. The cell contains hereditary information which
  is passed on from cell to cell during cell
  division.
• 5. All cells are basically the same in chemical
  composition and metabolic activities.

25
NextAnimal Cell Structure and Function