The OCR GCSE Biology Paper 4 (June 2021) addresses ecological concepts, genetic inheritance, and human health. Key topics include energy transfer in food chains, natural selection, amyloidosis, and genetic disorders like Down′s and Edward′s syndromes. Practical investigations explore decomposition, population estimation, and biomass pyramids. The paper highlights the use of monoclonal antibodies, gene silencing, and genetic engineering while integrating data analysis, risk assessment, and ethical considerations. It emphasizes the practical applications of biological concepts in agriculture, disease management, and conservation strategies.