Redi and Pasteur Experiments to disprove the theory of spontaneous generation

Last updated almost 7 years ago

23 questions

1

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Redi and Pasteur Experiments to disprove the theory of spontaneous generation

Last updated almost 7 years ago

23 questions

1

Last Name First Name

1

Origins of the Scientific Method
Redi's Experiment in 1668 and
Pasteur's Experiment in 1860

For over 2,000 years spontaneous generation was thought to be the process by which organisms came into existence.  People thought that frogs arose from the spring mud around ponds (not knowing that frogs hiberated during the winter in the mud) or that rats grew out of hay stacks in their barns.  People didn't realize that all organisms are born from other living organisms of their same species until scientists proved that the theory of spontaneous generation was false.  

For those that the video didn't load, here is the actual URL and you can try it on your phone or when you are at home: https://www.youtube.com/watch?v=WNByRghR6sw
 

For those whose chromebook didn't load the video here is the actual URL: https://www.youtube.com/watch?v=WzbHOY5fGqc

1

The supposed development of living organisms from nonliving matter such as maggots from rotting meat was disproved by Redi's experiment.  The theory of spontaneous generation for larger organisms that could be seen with the naked eye was easily shown to be false.   However,  the theory of spontaneous generation was not fully discredited until the mid-19th century with the demonstration of the existence and reproduction of microorganisms, most notably by Louis Pasteur.  Pasteur proves that all organisms including microorganisms come from other living organisms.

If the video didn't load automatically for you, here is the actual URL and you can try loading it on your phone or at home:  https://www.youtube.com/watch?v=Z7oLUWDeq7w

1

Give an example of how "pasteurization" has improved life for us.

Check your understanding of Pasteur's experiment by going to the textbook website:  classzone.com.  Select Animated Biology, Unit 1, and view the animation, "Chapter 1 Experimental Design."

1

The dependent variable was (type it exactly like what is in the animation):

1

The independent variable was (type it exactly like what is in the animation);

1

Control (type it exactly like what is in the animation):

1

Constant (type it exactly like what is in the animation):

Last Name First Name

Class Section

Origins of the Scientific Method
Redi's Experiment in 1668 and
Pasteur's Experiment in 1860

For over 2,000 years spontaneous generation was thought to be the process by which organisms came into existence.  People thought that frogs arose from the spring mud around ponds (not knowing that frogs hiberated during the winter in the mud) or that rats grew out of hay stacks in their barns.  People didn't realize that all organisms are born from other living organisms of their same species until scientists proved that the theory of spontaneous generation was false.  

For those that the video didn't load, here is the actual URL and you can try it on your phone or when you are at home: https://www.youtube.com/watch?v=WNByRghR6sw
 

For those whose chromebook didn't load the video here is the actual URL: https://www.youtube.com/watch?v=WzbHOY5fGqc

Redi's question was simply, "Where do maggots come from?"

True

False

Redi converted his question into a hypothesis so he could test where flies come from. To use the format:

"If (independent variable)...then..(dependent variable)."

His hypothesis was most likely something like:

If maggots originate from meat, then maggots will be found on the meat under all conditions."

True

False

Independent Variable:

A  number of fly maggots

B  flies

C  exposure to flies

D  the 3 jars

Dependent Variable:

A  number of fly maggots

B flies

C exposure to flies

D  the 3 jars

Examples of "controls" in this experiment included: the same style of jars, flies, exposure time, same temperature, light, and surroundings during the experiment

True

False

The "constant" in this experiment was the jar that was closed and sealed from exposure to the flies.

True

False

Redi had to use a gauze covered jar in his experiment because...

A  the gauze allowed air to reach the meat because his critics said that nothing could grow without air.

B  the gauze allowed the flies to lay eggs on it instead of the meat.

C  the gauze kept the flies from reaching the meat.

D  the gauze kept other organisms out of the jar.

Redi's Conclusion: Spontaneous generation was not true. Life comes from other life.

True

False

The supposed development of living organisms from nonliving matter such as maggots from rotting meat was disproved by Redi's experiment.  The theory of spontaneous generation for larger organisms that could be seen with the naked eye was easily shown to be false.   However,  the theory of spontaneous generation was not fully discredited until the mid-19th century with the demonstration of the existence and reproduction of microorganisms, most notably by Louis Pasteur.  Pasteur proves that all organisms including microorganisms come from other living organisms.

If the video didn't load automatically for you, here is the actual URL and you can try loading it on your phone or at home:  https://www.youtube.com/watch?v=Z7oLUWDeq7w

Pasteur's Question was probably something like, "What do bacteria which can't be seen with the naked eye grow from?"

True

False

Pasteur's Hypothesis was something like: If bacteria grow from the sterilized broth, then they will grow in any condition.

True

False

Independent Variable: exposure to the microorganisms in the air

True

False

Dependent Variable: growth of microorganisms in the broth

True

False

Constants in this experiment included the sterlized broth.

True

False

The word "sterlized" means that the broth was heated enough to kill all organisms living in it.

True

False

The clever use of the swan-neck flask allowed Pasteur to let microorganisms enter the flask, but not air.

True

False

Pasteur's conclusion was that all life, including microorganisms not seen by the naked eye, grow from other life forms. This conclusively disproved the theory of spontaneous generation.

True

False

Give an example of how "pasteurization" has improved life for us.

Check your understanding of Pasteur's experiment by going to the textbook website:  classzone.com.  Select Animated Biology, Unit 1, and view the animation, "Chapter 1 Experimental Design."

The dependent variable was (type it exactly like what is in the animation):

The independent variable was (type it exactly like what is in the animation);

Control (type it exactly like what is in the animation):

Constant (type it exactly like what is in the animation):

Class Section

A  A1

B  A2

C  A3

D  A4

E  A5

F  A6

G  A7

H  A8

Redi's question was simply, "Where do maggots come from?"

True

False

Redi converted his question into a hypothesis so he could test where flies come from.  To use the format:

 "If (independent variable)...then..(dependent variable)." 

His hypothesis was most likely something like:  

If maggots originate from meat, then maggots will be found on the meat under all conditions."

True

False

Independent Variable:

A  number of fly maggots

B  flies

C  exposure to flies

D  the 3 jars

Dependent Variable:

A  number of fly maggots

B flies

C exposure to flies

D  the 3 jars

Examples of "controls" in this experiment included:  the same style of jars, flies, exposure time, same temperature, light, and surroundings during the experiment

True

False

The "constant" in this experiment was the jar that was closed and sealed from exposure to the flies.

True

False

Redi had to use a gauze covered jar in his experiment because...

A  the gauze allowed air to reach the meat because his critics said that nothing could grow without air.

B  the gauze allowed the flies to lay eggs on it instead of the meat.

C  the gauze kept the flies from reaching the meat.

D  the gauze kept other organisms out of the jar.

Redi's Conclusion:  Spontaneous generation was not true.  Life comes from other life.

True

False

Pasteur's Question was probably something like, "What do bacteria which can't be seen with the naked eye grow from?"

True

False

Pasteur's Hypothesis was something like:  If bacteria grow from the sterilized broth, then they will grow in any condition.

True

False

Independent Variable:  exposure to the microorganisms in the air

True

False

Dependent Variable:  growth of microorganisms in the broth

True

False

Constants in this experiment included the sterlized broth.

True

False

The word "sterlized" means that the broth was heated enough to kill all organisms living in it.

True

False

The clever use of the swan-neck flask allowed Pasteur to let microorganisms enter the flask, but not air.

True

False

Pasteur's conclusion was that all life, including microorganisms not seen by the naked eye, grow from other life forms.  This conclusively disproved the theory of spontaneous generation.

True

False