IB Biology at the standard level consists of 110 hours of Theory (knowledge/instruction) covering a range of topics: statistical analysis, cells, the chemistry of life, genetics, ecology and evolution, and human health and physiology. In addition, one option topic will be covered. IB Biology students should acquire a limited body of facts and, at the same time, develop a broad, general understanding of the principles of the subject (IB Biology Course Description). Students are required to complete 40 hours of Practical Work (laboratory investigations), some of which will contribute to the internal assessment (IA). The IA counts as 20% of the grade awarded by IB.