Scientists and Theories


Warm-Up #13 10/19/11

1) What are two main differences between animal and plant cells?

2) Who was the plant scientist in the cell theory?

3) Who was the animal scientist?

* You have 10 minutes to get the warm-up done and make sure the homework is done from yesterday.

Scientists and


Essential Question

 What is the cause behind most infectious diseases?

Robert Hooke

 1665

 Coined term cell by looking at cork (plant) that resembled monastery’s tiny rooms.

 Saw cell walls

 Cell —the basic unit of life

 Used compound microscope

Anton van Leeuwenhoek

 1674

 First person to see living things!

Francesco Redi

 1668

 First controlled experiment!!

 Control was leaving one jar open — the experiment in the absence of the


 IV was the degree of coverage — gauze or completely sealed off

 DV was the result —did maggots appear?

Redi’s Experiment

What three men contributed to the cell theory?

 Plant guy —Matthias Schleiden

 Animal guy —Theodor Schwann

 Cell guy —Rudolph Virchow

Robert Koch

 Developed a series of rules to identify microorganisms that cause specific diseases.

 First to isolate tuberculosis, cholera, and anthrax!

 Won the Nobel Prize for TB.

Koch’s Postulates

1. Pathogen should be found in the body of a sick organism and not in a healthy one.

2. Pathogen must be isolated and grown in a laboratory in pure culture.

3. When cultured pathogens are placed in a new host, the host should get the same disease.

4. The pathogen should be isolated from the second host. It must be identical to the original.

Louis Pasteur

 Discovered fermentation of beer and wine is caused by microorganisms.

 Developed ‘Pasteurization’ for beer, wine, and milk.

 Developed vaccines for anthrax and rabies.

Louis Pasteur

 With the help of Robert Koch, Pasteur came up with the….

Germ Theory of Disease

 Infectious diseases are caused by microorganisms of different types, commonly called germs.


 Disease – any change, other than injury, that disrupts the normal function of the body.

Lynn Margulis

 Proposed that eukaryotic cells arose from living communities of prokaryotic cells.

 Called the endosymbiotic theory.

You must have at least 5 sentneces done before you leave today!