Performance of individual students in a tertiary level course is usually reflected in a final mark that determines their progress and transfer to higher courses. The contributions of different types of assessment to this final mark vary greatly within and between subjects in and between institutions. Performance of students in a first year course, Bioscience at the University of KwaZulu-Natal, Pietermaritzburg (UKZN) was assessed to determine if there were any patterns emerging in the broad components that contributed to the final mark, namely the coursework, theory and practical examinations. Performance of students was compared in Bioscience 110 for the years 1995-2000 using Repeated Measures ANOVA. Students performed best in coursework. All students performed poorly in the theory examinations. In addition differential performance between students, particularly the performance of sub-groups within the class was investigated. Of particular interest were English second language (ESL) students, and previous Science Foundation Programme (SFP) students. The latter are mainly previously disadvantaged Black students. All sub-groups of students showed similar trends in performance in Bioscience assessment tasks and final marks. However, the SFP students' final marks were lower than the other sub-groups, and showed a decreased performance for the same period. Most students, excluding SFP students, fell in the 50-59% category for the final Bioscience 110 marks obtained for the period 1995-2000. Theory examinations were investigated further, and were analysed in their component parts, namely multiple choice (MCQ), short questions and essay. Students performed best and consistently in MCQ. In contrast, students performed poorly in the short question and essay sections. Although the different ethnic sub-groupings showed similar trends in performance, the SFP students showed the poorest performance. In particular, they scored lowest in the theory examinations where they performed more poorly than the other sub-groupings in short questions and essays that require higher order cognitive skills. These patterns suggest that changes are required at the teaching, student and assessment interfaces.