The effect of monochromatic light on Drosophila melanogaster larvae: As measured by distance travelled

Abstract

Drosophila melanogaster, a species of fruit fly, have photoreceptors in their eyes to help them distinguish light and navigate in their environment (Keene et al. 2012). In this experiment, we obtained two groups of D. melanogaster larvae: the wild type and the rosy mutant, to investigate in which wavelength of light they will travel the greatest distance. Blue, red and white light acted as the treatments. After 30 seconds of each treatment, we observed how far the larvae travelled from the starting point. The distance travelled by the wild-type larvae exposed to white light was not found to be statistically different from the distance travelled in either blue or red light. However, the distance travelled when exposed to red light was found to be significantly different when compared to blue light. In the case of the mutant group, the distance travelled while under the exposure to white light was not statistically different from the distance travelled when exposed to red light. However, the distance was found to be significantly lower when exposed to blue light compared to that of white light. Based on the wild-type D. melanogaster data, we failed to reject the first null hypothesis, exposure to blue light will decrease or have no effect on the distance travelled in 30 seconds by wild-type D. melanogaster larvae as compared to white light. We also failed to reject the second null hypothesis, exposure to red light will increase or have no effect on the distance travelled in 30 seconds by wild-type D. melanogaster larvae as compared to white light. For the mutant D. melanogaster data, we failed to reject the third null hypothesis (similar to the first null hypothesis for wild type) and we also failed to reject the fourth null hypothesis (similar to the second null hypothesis for wild type).