1. Biological molecules1.1 Biological molecules1.2 Nucleotides and nucleic acids1.3 Enzymes1. Biological molecules1.1 Biological molecules1.2 Nucleotides and nucleic acids1.3 Enzymes2. Cells2.1 Cell structure2.2 Biological membranes2.3 Cell division, cell diversity and cellular organisation2. Cells2.1 Cell structure2.2 Biological membranes2.3 Cell division, cell diversity and cellular organisation3. Organisms exchange substances with their environment3.1 Exchange surfaces3.2 Transport in animals3.3 Transport in plants3. Organisms exchange substances with their environment3.1 Exchange surfaces3.2 Transport in animals3.3 Transport in plants4. Genetic information, variation and relationships between organisms4.1 Classification and evolution4.2 Patterns of inheritance4. Genetic information, variation and relationships between organisms4.1 Classification and evolution4.2 Patterns of inheritance5. Energy transfers in and between organisms (A-level only)5.1 Photosynthesis5.2 Respiration5. Energy transfers in and between organisms (A-level only)5.1 Photosynthesis5.2 Respiration6. Organisms respond to changes in their internal and external environments (A-level only)6.1 Communication and homeostasis6.2 Excretion as an example of homeostatic control6.3 Neuronal communication6.4 Hormonal communication6.5 Plant and animal responses6. Organisms respond to changes in their internal and external environments (A-level only)6.1 Communication and homeostasis6.2 Excretion as an example of homeostatic control6.3 Neuronal communication6.4 Hormonal communication6.5 Plant and animal responses7. Genetics, populations, evolution and ecosystems (A-level only)7.1 Communicable diseases, disease prevention and the immune system7.2 Biodiversity7.3 Ecosystems7.4 Populations and sustainability7. Genetics, populations, evolution and ecosystems (A-level only)7.1 Communicable diseases, disease prevention and the immune system7.2 Biodiversity7.3 Ecosystems7.4 Populations and sustainability8. The control of gene expression (A-level only)8.1 Cellular control8.2 Manipulating genomes8. The control of gene expression (A-level only)8.1 Cellular control8.2 Manipulating genomes