The OCR GCSE Biology Paper 2 (June 2021) covers ecological interactions, biodiversity, genetic inheritance, and human impacts on ecosystems. Topics include the water cycle, food webs, stem cells, and gene technology. It explores cancer causes, selective breeding, climate change effects, and adaptations like green coloration in skinks. Practical investigations address photosynthesis rates, sulfur dioxide impact, and population estimation using capture-recapture. The paper emphasizes experimental design, data interpretation, and ethical considerations in biological advancements.