Some understanding of biology is needed for the success of individuals in modern societies. This monograph is a report of an assessment of educational achievement by a sample of secondary school biology students in the United States within the context of current knowledge of teaching and learning strategies, the role of biological literacy in modern schooling, and some implications of the test results for improvement of modern biology education. The central focus of the report is a description of the test results for the first and second year biology students who participated in the Second International Science Study (SISS) sponsored by the International Association for the Evaluation of Educational Achievement (IEA). Discussions center on: (1) an "Introduction to biology education in modern society and the concept of biological literacy; (2) "Biological Curricula," which includes historical perspective, the Biological Sciences Curriculum Study, and biology textbook content; (3) "Studies on Biology Achievement"; (4) "The SISS: Rationale, Methodology, Instruments"; (5) "Results of the Second IEA Study: Biology Achievement"; and (6) "Conclusions," which contains findings and implications for biology curricula and learning. Each chapter includes a list of references. Appended are the first year and advanced biology content tests, student questionnaire items and responses, and mathematics tests given to the first year and advanced biology students. (CW)