Fruit Fly Experiment Essay

Similar to how we used water on both sides as a control in the baseline experiments, our first test was with dim light on both sides. To set up the chamber, we put 52 fruit flies in the double-sided chamber and sealed it tightly. Make certain to get at least 20 flies in the experiment for a larger set of data. That is why we put 52 flies in the choice chamber- to get substantial data. In order to count the number of flies on each side, draw a line going down the middle of the choice chamber to divide it into two halves. Side A is one half, and Side B is the other half. In this lab, we used red, blue, black, green, and 2 white light bulbs throughout the experiment. Additionally, to measure the intensity of the light hitting the choice chamber,

download an app to measure the Lux of the lights- light emittance. Two lights were fixed about a foot over the chamber, one on each side. We put the lights about a foot away from the chamber so that the heat emitted by the light would be minimal. We went to a room where we were are able to turn off all of the lights. Then, we turned off the lights in the room so that the only light sources were the two lights. We also placed a cardboard divider over the middle of the chamber to prevent most of the light from the colored light from the other side of the chamber. Our goal was to create a dim light with 5-15 Lux on Side B, so we covered the lights with a black folder to dim it to that range. We then let the flies move freely inside the chamber for 3 minutes for each trial, wrote observations, then counted the flies on each side.

We did 2 trials for each light situation in order to gather sufficient data. To test the colored lights, we placed the colored light bulb over Side A. We then recorded how many Lux the chamber was under, then waited 3 minutes, recorded observations and data, then did the same with all other lights: red, blue, black, and green. We decided to wait 3 minutes before counting in order to give the flies enough time to move from one end of the chamber to the other as well as time to respond to the stimuli. After collecting our data, we recorded it in a data table and calculated the Chi Square statistics. Our experimental comparison was between the preference of either dim or colored light by the flies. The dim light was on Side B throughout the entirety of the experiment as a constant while Side A varied from the different trials. We did not change the side of the dim light on Side B because it was the determined control, and Side A was determined to be the variable side just like in the water versus the other substance experiments we did previously. We are controlling for which side of the flies prefer, and which side the flies are repelled

by.