The OCR GCSE Biology Paper 1 (June 2023) examines topics such as photosynthesis, transpiration, DNA structure, mitosis, and hormonal regulation. Core sections explore kidney function, enzymes like catalase, and homeostasis mechanisms, including thermoregulation and blood glucose control. Investigative methods for plant growth and enzyme activity are emphasized, along with practical applications like microscopy and experimental design. The paper includes data interpretation, diagrams, and critical analysis of biological systems, focusing on ethical and practical considerations in biology.