Spontaneous Generation Notes Outline
Spontaneous Generation
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Who was the first person to come up with the idea of Spontaneous
Generation?
o _______________________________________ (384 – 322 BC)
 Spontaneous Generation- the idea:
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Spontaneous Generation is also known as known as ______________________________________
The idea of spontaneous generation lasted for almost 2000 years!
For centuries, what did people base their beliefs on?
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They didn’t use the _______________________ __________________________ to arrive at answers to their
questions
Their conclusions were based on _______________________ _________________________
Scientists Who Worked to Disprove Spontaneous Generation
1.)Francesco Redi
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In 1668, Francesco Redi, an Italian physician, did an experiment with __________________ and
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What did Francesco Redi do?
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What was his hypothesis?
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What did Redi observe from his experiment? What were his
findings?____________________________________________________________________________________________________
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Did Redi disprove Spontaneous Generation?
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The results of Redi’s experiment ________________________ the idea of spontaneous generation
for ________________________ ________________________ (such as flies, mice, bees, etc.)
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But people still thought ________________________ ________________________ like algae or bacteria
could arise through spontaneous generation.
2.)
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3.)
Anton van Leeuwenhoek
Leeuwenhoek began making and looking through ______________________ ______________________
He often made a new microscope for each specimen
He examined water and visualized tiny animals, fungi, algae, and single celled protozoa
called ________________________
By end of 19th century, these organisms were called ________________________
John Needham
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What did John Needham do?
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Did Needham’s experiments prove spontaneous generation?
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4.)
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Lazzaro Spallanzani (1765)
Boiled soups for almost an hour and sealed
containers by melting the slender necks closed.
The soups remained clear.
Later, he broke the seals & the soups became
cloudy with microbes
Critics said sealed vials did not allow enough air
for organisms to survive and that prolonged
heating destroyed life force
*Therefore, spontaneous generation remained the theory of the time
The Theory Finally Changes!
How do Microbes Arise?
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By 1860, the debate had become so heated that the Paris Academy of Sciences offered a prize
for any experiments that would help resolve this conflict
The prize was claimed in 1864 by ________________ ________________, as he published the results
of an experiment he did to disproved spontaneous generation in microscopic organisms
Pasteur’s Problem
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What was Pasteur’s Hypothesis? :
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Pasteur put broth into several special S-shaped flasks. Each flask was boiled and placed at
various locations
Pasteur’s Experiment – Step 1
What did he do?:
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Pasteur’s Experiment – Step 2
What did he do?:
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Pasteur’s Experiment – Step 3
What did he do?:
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The Theory of Biogenesis
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Pasteur’s S-shaped flask kept _________________________________________
_________________________________________________________________.
Proved microbes only come from other microbes (life from life) - ________________________
Pasteur’s Experimental Results
The Cell Theory
Directions: Use the following websites to answer the questions below
about the contributors to the cell theory.
1. Cell Theory:
a. List the three parts of the Cell Theory.
1. ________________________________________________________________
2. ________________________________________________________________
3. ________________________________________________________________
b. How does the Cell Theory disprove spontaneous generation? _______________________
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*Use these websites to answer question 1
http://www.smithlifescience.com/celltheory.htm
http://www.timetoast.com/timelines/cell-theory-timeline--3
*Use these websites to answer questions 2-4
Schleiden, Schwann & Virchow:
 http://en.wikipedia.org/wiki/Theodor_Schwann
 http://migration.wordpress.com/2007/03/02/basics-cell-theory/
 http://science.jrank.org/pages/6408/Spontaneous-Generation.html
 http://en.wikipedia.org/wiki/Rudolf_Virchow
2. Matthias Schleiden:
a. When was Matthias Schleiden born? _________________________________________
b. When did he die? ____________________________________________________
c. What generalization made by Schleiden became part of the Cell Theory?
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d. What idea did Schleiden have about how plant growth occurred?
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e. Why might this idea be important for the Cell Theory?
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3. Theodor Schwann:
a. When was Theodor Schwann born? _________________________________________
b. When did he die? _________________________________________
c. What two fields of science were unified by Schwann and Schleiden’s work?
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d. What did they find that was similar between plants and animals?
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e. How might Schwann’s observations about embryos have affected the theory of
spontaneous generation? ___________________________________________________
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4. Rudolf Virchow:
a. When was Rudolf Virchow born? _________________________________________
b. When did he die? _________________________________________
c. What famous book did Virchow write? _________________________________
d. What idea did that book contribute to the Cell Theory? ________________________
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e. How would this idea affect scientists’ acceptance of spontaneous generation? _________
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