Topic 1: Biological molecules Carbohydrates, lipids, proteins; Enzymes; DNA and RNA; ATP, water, inorganic ions. Topic 2: Cells Cell structure; Cell division; Transport across cell membranes; The immune system. Topic 3: Organisms exchange substances with their environment Gas exchange; Digestion and absorption; The heart and blood transport in animals; Water and glucose transport in plants. Topic 4: Genetic information, variation, and relationships between organisms DNA, genes, and chromosomes; Protein synthesis; Genetic diversity by mutation or meiosis Classification and taxonomy. Topic 5: Energy transfer in and between organisms Photosynthesis; Respiration; Energy and ecosystems; Nutrient cycles. Topic 6: Organisms respond to changes in their internal and external environments Control of Heart Rate; The nervous system and receptors; and Muscles; Control of body temperature, blood glucose, and blood water. Topic 7: Genetics, populations, evolution and ecosystems Genetic inheritance; Evolution and natural selection; Ecosystems and ecology. Topic 8: The control of gene expression Control of gene expression; Using genome projects; Gene technologies and genetic engineering. Students will also complete 12 required practicals over the two years including an investigation into the effect of a named variable on the rate of an enzyme-controlled reaction; Production of a dilution series of a solute to produce a calibration curve with which to identify the water potential of plant tissue; Dissection of animal or plant gas exchange or mass transport system.