In this activity, students apply their knowledge of models of inheritance (dominant-recessive, co-dominance, incomplete dominance, multiple alleles, and sex-linked) to determine how fruit flies inherit a specific trait. The guiding question for the investigation is: Which model of inheritance best explains how a specific trait is inherited in fruit flies? Students use an online simulation called Drosophila(http://www.sciencecourseware.org/vcise/drosophila/) to conduct their investigation. Students select two fly traits (eye color, body color, wing shape) from a menu provided in the simulation, decide on how many times they will breed them over several generations, collect data, and determine which model of inheritance is the best explanation for a particular trait. After completing the investigation, students prepare a whiteboard presentation that includes the guiding question, claim, evidence, and justification of explanatory model of inheritance evidence and present it to the whole-class using a round-robin format. A round-robin format means that one member of the group will stay at the lab station to share the group’s argument while the other members of the group rotate to other lab stations one at a time to listen to and evaluate the arguments of other groups. After collecting feedback, students revise the initial claim before writing a final report. Also, students answer the checkout questions at the end of the activity. The book includes an option to extend the lesson by asking students to complete a double-blind peer review of the argument using a rubric provided in the appendix. To provide additional support, four appendixes are included: standards alignment matrixes, options for implementing argument-driven inquiry lab investigations, investigation proposal options, and peer-review guide and instructor scoring rubric. A detailed step-by-step guide that explains the argument-driven inquiry is included for teachers not familiar with the model. This activity can be completed in 180-250 minutes.