Summative assessments are customarily used to evaluate ultimate student outcomes and typically occur less frequently during instruction than formative assessments. Few studies have examined how the use of summative assessments may influence student learning among at-risk groups of students. Summative assessments are typically used to evaluate how much learning has occurred. This study investigates how summative assessments could be used to reduce the achievement gap among at-risk groups of students in an introductory biology course. Students were given low-stakes practice exams between high-stakes midterm exams. These practice questions were delivered in different modalities throughout three semesters in an introductory biology course. Survey questions were also given out at the end of each semester to identify student preferences for different modes of practice questions' delivery. Students preferred the mixed model of delivering practice exam questions, that is, they completed some online and some during lecture; however, overall result shows that all students, including at-risk groups, had the greatest performance when practice questions were delivered face-to-face during lectures.