Teacher Information Francesco Redi



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Francesco Redi - One of the first to disprove spontaneous generation. An Italian doctor who proved maggots came from flies. (Italian 1668)

Spontaneous Generation

  • The idea that organisms originate directly from nonliving matter.

  • "life from nonlife"

  • abiogenisis - (a-not bio-life genesis-origin)




Redi's Problem

Where do maggots come from? 

Hypothesis: Maggots come from flies.

Redi put meat into three separate jars.

Jar 1 was left open 

Jar 2 was covered with netting

Jar 3 was sealed from the outside


http://faculty.sdmiramar.edu/dtrubovitz/micro/history/redi1.gif

Redi's Experiment Step 1

Jar-1

Left open 

Maggots developed

Flies were observed laying eggs on the meat in the open jar



http://faculty.sdmiramar.edu/dtrubovitz/micro/history/redi2.gif

Redi's Experiment Step 2

Jar-2

Covered with netting 

Maggots appeared on the netting

Flies were observed laying eggs on the netting



http://faculty.sdmiramar.edu/dtrubovitz/micro/history/redi3.gif

Redi's Experiment Step 3

Jar-3

Sealed 


No maggots developed

http://faculty.sdmiramar.edu/dtrubovitz/micro/history/redi4.gif

Redi's Experiment Results

What did Redi's experiment show? 

Was his hypothesis correct or incorrect?




Name __________________________________________________ Date ____________________________Per_______



Francesco Redi’s Experiment- Spontaneous Generation


Background: Spontaneous generation is the hypothesis that some vital force contained in or given to organic matter can create living organisms from inanimate objects. Spontaneous generation was a widely held belief throughout the middle ages and into the latter half of the 19th century. Here is an example of an experiment that was offered in proof: to create mice, dirty underwear and wheat grain are to be mixed in a bucket and left open outside. In 21 days or less, you would have mice. The proponents of this idea believed that the mice arose spontaneously from the wheat kernels. Another often-used example was the generation of maggots from meat that was left in the open. In 1668 Francesco Redi conducted a classic experiment to disprove the idea of spontaneous generation. Redi wanted to find out: where do maggots come from?


Challenge: Can you replicate Redi’s experiment using three jars, 3 pieces of meat, a piece of cheesecloth (netting), a piece of plastic wrap, and two pieces of string?

A. What do you think Redi’s hypothesis was?_____________________________________________________________

_______________________________________________________________________________________________

B. Experimental Design: Use the materials listed above to design an experiment to test Redi’s hypothesis. Draw a sketch of your design below:



C. Describe how each jar can be used to provide evidence against spontaneous generation.

D. What is the expected outcome of Redi’s experiment?


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