A major challenge in teaching the process of science to students is designing and implementing laboratory activities that emulate what is actually done in a research laboratory. To facilitate this effort, science educators have been encouraged to design exercises that span multiple laboratory periods, encourage independent thinking, promote hypothesis-driven experimentation, and data collection and analysis. We have designed an inquiry-based, semester-long laboratory activity amenable to majors or nonmajors and to introductory or advanced biology students. This activity utilizes "Drosophila melanogaster", the fruit fly, as a model organism that allows students to investigate how different rearing media additives affect female fecundity measured as numbers of eggs laid. To explore the feasibility of our activity aimed in helping students learn the processes of science, we assigned the activity independently to three different student populations. These included 1) students in an undergraduate biology laboratory; 2) an independent undergraduate research project; 3) a Distance Education Biology Master's graduate student summer research project. The goal of this laboratory activity is to allow students the opportunity to design a controlled experiment, formulate testable hypotheses, identify variables, make quantitative and qualitative observations, and analyze data using a simple computer spreadsheet program. (Contains 3 figures.)