The OCR GCSE Biology Paper 3 (May 2023) covers core biological concepts such as photosynthesis, respiration, and enzyme function. Topics include kidney function, genetic mutations, stem cell therapy, and the role of hormones in processes like IVF and glucose regulation. Practical investigations focus on osmosis in plant cells, enzyme-substrate interactions, and the use of leaf discs to measure photosynthesis. The paper emphasizes scientific methods, data analysis, and experimental design while addressing ethical and applied biological issues in genetic disorders and biotechnology.