This study examines the impact of integrating worked examples into a Cognitive Tutor for genetics problem solving, and whether a genetics process modeling task can help prepare students for explaining worked examples and solving problems. Students participated in one of four conditions in which they engaged in either: (1) process modeling followed by interleaved worked examples and problem solving; (2) process modeling followed by problem solving without worked examples; (3) interleaved worked examples and problems without process modeling; or (4) problem solving alone. Tutor data analyses reveal that process modeling led to faster reasoning and greater accuracy in explaining problem solutions. Process modeling and worked examples together led to faster reasoning in problem solving than did any of the other three conditions. Students in all conditions achieved equivalent problem-solving knowledge, as measured by posttest accuracy, although the tutor results suggest reasoning speed may be a more sensitive measure of learning.