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John Need-ham heated broth in sealed flasks in 1745
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Why MacConkey agar is solid at room temperature while MacConkey broth remains Liquid at room Temperature?
MacConkey agar is solid at room temperature because it is a gel-like polysaccharide. Broth that has 1.5 percent agar in it and is heated up will become a liquid.
What did Lazzaro Spallanzani contributes to microbiology?
He repeated John Needham's experiment in which nutrient fluids (Chicken broth) was put into a sealed flask then heated. The nutrient medium could be stored and microoganisms did not arise from it. This experiment disproved the Spontaneous Generation and paved the way for Pasteur's research. Spallanzani was largely criticised under claims that microorganisms needed oxygen to survive. He was also a pioneer in the fertilization an experiment which he produced with frogs. :) hope that helps.
Explain the results in the sterilized and not-sterilized broth?
Sterilized broth is clear, meaning no bacterial growth. Non-sterilized broth is cloudy.
Which scientist used boiled beef broth and flasks with S-shaped tubing to show that the theory of spontaneous generation is false?
He disproved that living cells come from nonliving things.
Why is nutrient broth better than peptone broth?
Nutrient broth contains beef extract which acts as sources of amino acids, peptides, nucleotides, organic acids, vitamins and mineralsthat peptone broth don't contain? :)
What would have happened is Pasteur had tipped on of his flasks so that the broth in the flask came into contact with the curve of the neck?
If the pasteur tipped on of his flasks so that the broth came into contact with the curve of the neck, the sterile broth soon became contaminated with microorganisms which were trapped in the curve.
What are the contolled variables in spallanzani's experiment?
flasks, broth, time, location, time, temperature.
Why are beakers and flasks not used for heating solids?
the heat may not be distributed uniformly if solids are heated in beakers or flasks
Why did pasteur boil the broth in both flasks?
To kill any organisms that may have come in through the air.
Who used broth and flasks to disprove spontaneous generation?
Your mom was the first one. you ain't know?
What is butter broth?
Heated butter mixed with the broth of a bird, very good with turkey.
What are flask tongs?
I think you mean tongs used to grip hot flasks which are used in casting metal objects, or could be handling flasks of radioactive materials inside sealed chambers. this obviously has to be done remotely.
What are the uses of a flask?
The round bottoms on these types of flasks allow more uniform heating and/or boiling of liquid. Thus, round-bottom flasks are used in a variety of applications where the contents are heated or boiled. Round-bottom flasks are usually used in distillation by chemists as distilling flasks and receiving flasks for the distillate One-neck round-bottom flasks are used as the distilling flasks in rotary evaporators.This flask shape is also more resistant to fracturing under vacuum, as a sphere more evenly distributes stress across its surface.
What is the independent variable in Pasteur's experiment?
The answer was that the independent variable was the broth that wasn't heated
How was spontaneous generation disproved twice?
Fransesco Redi: took 3 jars of rotten meat and the 1st was uncovered the second was covered with gauze and the 3rd was sealed with thick parchment. Results: 1. jar number 1 was infested with flies and maggots 2. jar number 2 had fly's eggs laid on top of the gauze 3. jar number 3 attracted no flies because it was sealed off and the flies could not smell it; this disrpoved the theory that flies evolved from rotten meat but in reality only hatched their eggs inside the meat so the maggots (baby flies) could have something to eat after they hatched. Louis Pasteur: broiled broth and set the broth inside flasks; some were covered and some weren't; the ones uncovered were infested with bacteria and the ones that were covered were not infested with bacteria. Then, he took a flasks with broiled broth inside the flasks and toom them to a mountain top. The results ended as he thought. The bacteria inside the broth was few because of the thin air. the final experiment was with broth uncovered inside a flask that had a zig-zag motion. Results: the bacteria did not infest the broth but settled on the curves of the flask and could not reach the broth. Without these two scientists (which lived about 200 years ago) the thought of spontaneous generation would have carried on through today; it still did with the stupidity of "so called" evoulutionists which call themselves scientists even thought evoulution is only a faith instead of a science or fact.
Which of the following is the dependent variable in this experiment?
The independent variable is the one that the experimenter changes, and the dependent variable is the response. For example - if you were doing an experiment about the affect of temperature on growth rates: Temperature = Independent variable Growth = Dependent variable
What will happen in a sealed bottle when the air is heated and then allowed to cool?
The bottle will collapse when the bottle has heated air
