1. Carbon Cycle and Ecosystem Relationships | Mutualism in ecosystems, role of decomposers in carbon cycling, energy transfer through food chains, and the importance of photosynthesis in carbon fixation. 2. Enzymes and Digestion | Effect of temperature on enzyme activity, denaturation at high temperatures, enzyme-substrate interactions, and practical investigations into enzyme function. 3. Circulatory System and Blood Transport | Structure and function of arteries, veins, and capillaries, blood pressure variations, role of valves in veins, and movement of blood to the lungs by heart contractions. 4. Hormones and the Endocrine System | Role of adrenal glands in adrenaline production, effects of hormones on bodily functions, menstrual cycle regulation by estrogen and progesterone, and contraceptive methods. 5. Diabetes and Blood Glucose Control | Comparison of blood glucose levels in diabetics vs. non-diabetics, insulin function, osmosis effects on red blood cells, and strategies to manage Type 2 diabetes. 6. Respiration and Exercise | Differences between aerobic and anaerobic respiration, impact of running on breathing rate, energy production variations, and investigation of CO₂ levels in exhaled air at different exercise intensities.