What was the control group in Pasteur experiment?

Asked By: Arlene Empis | Last Updated: 18th June, 2020
Category: science chemistry
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After sterilizing a nutrient broth in these flasks, he removed the swan necks of the samples in the control group. Microorganisms grew in the control group, but not the experimental group, supporting biogenesis and rejecting spontaneous generation.

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Correspondingly, what was the control in Pasteur's experiment?

Pasteur's experiments contained both positive controls (samples in the straight necked flasks that he knew would become contaminated with microorganisms) and negative controls (samples in the sealed flasks that he knew would remain sterile).

Also Know, why did Pasteur bend the neck of the flask? He concluded that germs in the air were able to fall unobstructed down the straight-necked flask and contaminate the broth. The other flask, however, trapped germs in its curved neck, preventing them from reaching the broth, which never changed color or became cloudy.

Simply so, what was the independent variable in Pasteur's experiment?

The independent (manipulated) variable was the gauze. The dependent variable was what resulted from leaving the control group open, which was the appearance of maggots. One jar of meat was open, and the other jar of meat was covered with gauze.

What was Pasteur's hypothesis?

Pasteur's Problem Where do the microbes come from to cause broth to decay. Hypothesis: Microbes come from cells of organisms on dust particles in the air; not the air itself.

31 Related Question Answers Found

What is the theory of biogenesis?

Biogenesis is the theory that living things can only come from other living things. It was developed in 1858 by Rudolf Virchow as a counter-hypothesis to spontaneous generation. Before Virchow, it was widely accepted that microorganisms simply appeared as a result of spontaneous generation.

What was the result of Pasteur's experiment?

CONCLUSION. Pasteur's experiment showed that microbes cannot arise from nonliving materials under the conditions that existed on Earth during his lifetime. But his experiment did not prove that spontaneous generation never occurred. Eons ago, conditions on Earth and in the atmosphere above it were vastly different.

What is Redi's experiment?

In 1668, Francesco Redi, an Italian scientist, designed a scientific experiment to test the spontaneous creation of maggots by placing fresh meat in each of two different jars. Redi successfully demonstrated that the maggots came from fly eggs and thereby helped to disprove spontaneous generation. Or so he thought.

Who discovered germs?


Louis Pasteur

Does biogenesis explain the origin of life?

Explanation: Biogenesis is the production of new living organisms or organelles I.e. life arises from preexisting life. The ancient Greeks believed that living things could spontaneously come into being from non living matter.

Who proved spontaneous generation wrong?

Francesco Redi disproved spontaneous generation for large organisms by showing that maggots arose from meat only when flies laid eggs in the meat.

What is the concept of spontaneous generation?

Spontaneous generation, the hypothetical process by which living organisms develop from nonliving matter; also, the archaic theory that utilized this process to explain the origin of life. Many believed in spontaneous generation because it explained such occurrences as the appearance of maggots on decaying meat.

Why is it important to use a control in an experiment?

A control is important for an experiment because it allows the experiment to minimize the changes in all other variables except the one being tested.

What was the responding variable in Redi's experiment?


SPONTANEOUS GENERATION
A B
Maggots Larvae of flies.
Manipulated variable The one factor that a scientist changes in an experiment.
Controlled experiment An experiment in which all factors are identical except one.
What was the manipulated variable in Redi's experiment? Jar cover

What are variables in an experiment?

A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and controlled. The independent variable is the one that is changed by the scientist.

How does the evidence derived from this experiment refute the idea of spontaneous generation?

How does the evidence derived from this experiment refute the idea spontaneous generation? the evidence derived from this experiment refutes the idea of spontaneous generation because in order to have generation there must be contamination were spontaneous generation just comes out of no where and that is not possible.

Is spontaneous generation of microbial life possible?

Spontaneous generation is the idea that living organisms can spontaneously come from nonliving matter. Over the years great minds like Aristotle and Isaac Newton were proponents of some aspects of spontaneous generation which have all been shown to be false.

What was the question Pasteur wanted to answer?

Francesco wanted to find the answer to the question, "Do maggots (flies) come from rotting meat?".

Why did the broth in Pasteur's experiment remain sterile?

Pasteur experiment number 2! Demonstrated that sterile broths in specifically constructed swan neck flasks remained sterile even when left open to air . Microorganisms from the air settled in the bends and sides of the flasks ,never reaching the broth. Only when the flasks were tipped would bacteria enter and grow .

What did Pasteur use swan neck flasks for?

As a result, sterile liquid in the vessel itself remains sterile as long as the liquid does not contact the contaminated liquid in the tube. Louis Pasteur developed and used this apparatus in 1859 to prove that particles in the air (germ theory), rather than the air itself (spontaneous generation), led to fermentation.