The OCR GCSE Biology Paper 3 (November 2021) covers photosynthesis, cellular respiration, and the immune system. Key topics include genetic inheritance, blood sugar regulation, and food security threats. Practical investigations address enzyme activity, selective breeding, and the effects of light intensity on photosynthesis. Ethical considerations in stem cell research, disease-resistant breeding, and antibiotic resistance are examined. The paper emphasizes data interpretation, experimental design, and real-world applications in disease control, conservation, and agricultural sustainability. Biological processes and their broader environmental and societal impacts are central themes.