Problem solving is an integral part of doing science, yet it is challenging for students in many disciplines to learn. We explored student success in solving genetics problems in several genetics content areas using sets of three consecutive questions for each content area. To promote improvement, we provided students the choice to take a content-focused prompt, termed a "content hint," during either the second or third question within each content area. Overall, for students who answered the first question in a content area incorrectly, the content hints helped them solve additional content-matched problems. We also examined students' descriptions of their problem solving and found that students who improved following a hint typically used the hint content to accurately solve a problem. Students who did not improve upon receipt of the content hint demonstrated a variety of content-specific errors and omissions. Overall, ultimate success in the practice assignment (on the final question of each topic) predicted success on content-matched final exam questions, regardless of initial practice performance or initial genetics knowledge. Our findings suggest that some struggling students may have deficits in specific genetics content knowledge, which when addressed, allow the students to successfully solve challenging genetics problems.