What is the independent, dependent variable, control group and hypothesis?

Points to whoever answers it first and correctly





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In the early 1660s the theory of ';spontaneous Generation'; prevailed. Spontaneous generation, means that people believed that living things came from non-living things. For example, many people noticed that around butcher shops there were often a lot of flies. So naturally, people thought that flies come from the meat. However, a scientist name Francesco Redi thought otherwise. He designed the experiment shown below. He placed meat in three different jars that were the same shape and size and left the jairs our on his balcony. One jar he covered with paper, allowing no air to get it, one jar he covered with gauze, which allowed air to get in, but kept other things out, and in another jar he left open. He noticed that the jar that he left open had flies in the jar and all over meat. The jar was paper had no flies in the jar or on the paper. The jar with the gauze had no flies in the jar, but maggots (baby flies) on the gauze.What is the independent, dependent variable, control group and hypothesis?
hypothesis - flies come from something other than meat (non-living things)





independent variable (the changes made by the researcher) - type of covering on the jars





dependent variable (what results from each change made by the researcher) - if flies appeared or not





control group (group with no change) - the jar with no covering











EDIT: The hypothesis was tested by not allowing anything INTO the jars containing the meat. Popular opinion was that the meat itself produced the flies (abiogenesis, or life from non-life). By trying different converings over the jars (and these were gauze and a lid, not paper) and leaving one open, he could determine if something had to enter the jar to cause maggots to be on the meat. If the popular opinion was correct, there should have been maggots in all the jars, because they all contained meat. But ONLY the jar that was open actually had the maggots on the meat. The one covered by gauze had maggots on the outside on the gauze (flies laid their eggs on the gauze, close to the meat), and the one with the lid had nothing (the flies weren't able to detect the meat in the closed jar). So by doing this, he was able to show that there had to be something besides just the meat that was causing the maggots and eventually flies.





And because he was testing to see if something OTHER THAN just the meat caused the maggots, he manipulated the other jars (his experimental units) by putting on different types of covers. Because the OPEN jar wasn't changed (was left open to the air, just like the meat in the butcher shops) this was the CONTROL. The answer has it wrong, whenever you make a change above what are the ';normal conditions'; (like covering a jar), then this can't be the control.





More about Redi's experiment with the hypothesis, variables, and control identified: http://biology.clc.uc.edu/courses/bio114鈥?/a>What is the independent, dependent variable, control group and hypothesis?
The control group is usually what is left untreated or unexposed to the procedure, in this case the air exposure. The control group: The jar with no air because it was covered with paper.





The hypothesis: First off what would key you in on the hypothesis of the experiment is Redi's opposition to spontaneous generation, that spontaneous generation is the incorrect ideology in regards to the origin of living things. Since he thought otherwise he believed that the flies did not come from the meat but rather from the exposure to air. Not necessarily that air would generate flies, but that being exposed to the air allows flies to get into contact with your meat and lay eggs (hence the partial air exposure left maggots). Since he thought that flies came from flies he did not believe in spontaneous generation.





Independent variable is the variable that is being manipulated or changed. That would be the independent variable is the type of exposure to air the meat is getting. The control has no air exposure, the other jar has partial air exposure (the gauze), and the final jar has total air exposure.





Dependent variable is the observed result from the independent variables. The dependent variable is the amount of flies/maggots in the jar.