The purpose of having a control when doing a lab is because it is the part that is already known and not likely to change. It is always important to have a stable variable in any experiment you do. This also helps with overlooking hidden variables so you can compare how the organisms in the control behaved differently from those in the experimental situation. The purpose of having multiple variables is to compare the difference between the outcomes with each of the different variables. It is important to have large number of organisms so there is more of a population. Watching one fish would not be accurate because they do not account for the body of fish but having more fish means having more of an accurate outcome of what the whole body of fish would actually do. If I were to repeat this procedure, I would probably calculate every 5 minutes but after I do, I would wait one minute and calculate again how many fish were in each area. There were a lot of times when 5 minutes would be up then I would notice the fish moving into another area 5 seconds later. The variables that the fish responded to were the warm and bright area on one side and the cool and dark area on the opposite side and the normal temperatures in the middle. Due to our calculations, the fish like to be in the warmer temperature with bright lights! This is because it is easier for them to see and it was not overbearingly hot, it was just right.
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