Contribution: A conceptual model for task allocation among student teams in project-based learning (PBL) is proposed in this paper, along with a discussion on ways gender can affect teams' apportioning of roles in inequitable ways in STEM PBL. Background: Studies find that men and women report taking on different roles in PBL projects, and that there is a relationship between team gender breakdown and students' satisfaction with PBL teams, with teams less happy with the inclusion of more women. Both male and female students on teams with two or more women report lower team satisfaction than men on teams of just men, or men and women on teams with a single woman Research Questions: How do students self-select, negotiate, and allocate tasks on PBL teams? How does past PBL experience influence task allocation? How does gender affect task allocation? Methodology: First-year students (N = 60) completed reflections about task assignment during a semester-long PBL experience. Findings: Individual student characteristics that are related to gender - including interests, skills, experiences, and self-efficacy - interact with students' goal orientations to lead to individual preferences regarding tasks. Ultimate task allocations are distributed in a non-gender-neutral way following individual preferences.