This Guide aids preparation for IBDP Biology Paper 3: Option D: Human Physiology. Reviewing all SL and HL topics, it builds understanding, highlights essential information, and develops the skills required for success in the exam. Coverage includes: human nutrition; digestion; functions of the liver; the heart; hormones and metabolism; and transport of respiratory gases. Key features: concise definitions of important terms and concepts; clearly labelled diagrams that are easy to reproduce in exams; and practice questions and self-test quizzes.