Every subtopic of DP Biology, ready to teach.

Theme A spans 26 lessons across 9 topics — A1.1 Water, A1.2 Nucleic acids, A2.1 Origins of cells (HL), A2.2 Cell structure, A2.3 Viruses (HL), A3.1 Diversity of organisms, A3.2 Classification & cladistics (HL), A4.1 Evolution and speciation, and A4.2 Conservation of biodiversity. Together these topics establish the molecular, cellular, and evolutionary foundations of the course, framed by key concepts including Structure and function, Unity and diversity, and Evolution.

Skills & assessment. Students practise interpreting electron micrographs, constructing and reading cladograms, evaluating evidence for evolutionary mechanisms, and applying conservation strategies to real-world issues — developing the analytical and evaluative skills required for AO3 and AO4 questions in the external examinations.

Theme B spans 30 lessons across 10 topics — B1.1 Carbohydrates & lipids, B1.2 Proteins, B2.1 Membranes & membrane transport, B2.2 Organelles & compartmentalisation, B2.3 Cell specialisation, B3.1 Gas exchange, B3.2 Transport, B3.3 Muscle & motility (HL), B4.1 Adaptation to environment, and B4.2 Ecological niches. The theme is unified by the key concept of Form and function, tracing how molecular architecture determines biological role at every level of organisation.

Skills & assessment. Lessons develop skills in interpreting structural diagrams, analysing pressure–volume data for the cardiac cycle and ventilation, applying the sliding filament theory, and evaluating physiological and behavioural adaptations — equipping students to tackle both data-based and extended-response questions aligned to AO2–AO4.

Theme C spans 27 lessons across 9 topics — C1.1 Enzymes & metabolism, C1.2 Cell respiration, C1.3 Photosynthesis, C2.1 Chemical signalling (HL), C2.2 Neural signalling, C3.1 Integration of body systems, C3.2 Defence against disease, C4.1 Populations & communities, and C4.2 Transfers of energy & matter. The theme is unified by the key concepts of Interaction and Interaction and interdependence, examined at molecular, cellular, organismal, and ecosystem scales.

Skills & assessment. Students practise interpreting rate–concentration graphs for enzyme kinetics, tracing electrons through the Z-scheme and electron transport chain, analysing reflex arc diagrams, evaluating immune responses, and constructing energy flow models — building the quantitative and evaluative competencies required for AO2–AO4 exam questions.

Theme D spans 36 lessons across 12 topics — D1.1 DNA replication, D1.2 Protein synthesis, D1.3 Mutations & gene editing, D2.1 Cell & nuclear division, D2.2 Gene expression (HL), D2.3 Water potential, D3.1 Reproduction, D3.2 Inheritance, D3.3 Homeostasis, D4.1 Natural selection, D4.2 Stability & change, and D4.3 Climate change. The theme is structured around the key concepts of Continuity and change and Homeostasis, connecting molecular genetics to population-level and planetary-scale processes.

Skills & assessment. Lessons develop skills in interpreting Meselson–Stahl evidence, solving dihybrid crosses with chi-squared tests, applying the Hardy–Weinberg equations, evaluating CRISPR ethics, and analysing data on climate change impacts — providing comprehensive preparation for the quantitative, evaluative, and extended-response demands of Papers 2 and 3.

Skills & assessment.