The OCR GCSE Biology Paper 4 (June 2023) covers plant and human physiology, genetic inheritance, and ecological interactions. Key topics include photosynthesis, mitosis, the role of chloroplasts and mitochondria, and the regulation of blood sugar levels. It explores the impacts of mutations, environmental adaptations, and disease control in humans and plants. Practical investigations include enzyme activity in fungi, soil pH analysis, and genetic studies on elephants. Ethical considerations in stem cell use and conservation strategies for at-risk species are also emphasized. The paper integrates experimental design, data analysis, and real-world applications.