Exam Focus

Exam Focus

Blood components and function are core AQA content examined in almost every series. The most common question formats are:

• 2-mark describe questions: "Describe two adaptations of red blood cells for their function." Always state the adaptation AND explain how it helps (e.g., biconcave shape increases surface area, so oxygen diffuses in and out faster).
• 4-mark comparison tables: Artery, vein, and capillary structure and function comparisons are a reliable exam staple. Learn the table on this page.
• 6-mark extended response: "Explain how a red blood cell is adapted to carry oxygen efficiently." For full marks you must cover at least three adaptations, each with a clear structure-to-function explanation.
• Application questions: Contexts involving anaemia, blood clotting disorders, or exercise are used to test whether you can apply your knowledge (e.g., "A patient has haemophilia. Explain why a small cut could be dangerous.").

Key command words: "Describe" (state the feature), "Explain" (state feature + why it helps), "Compare" (similarities AND differences). Never just list — always link structure to function.

Edexcel 1BI0 Paper 2 (T8 — Exchange and Transport in Animals): Edexcel blood component questions often appear as scenario-based items — a patient case study describing abnormal blood counts or a clotting disorder, with "explain" and "suggest" questions asking you to apply your knowledge of red blood cells, white blood cells, platelets, and plasma. Micrograph images of blood smears may be provided and you may be asked to identify cell types and explain their adaptations. Edexcel mark schemes use "Accept…" and "Allow…" for equivalent descriptions of cell function, so plain-English structural explanations are credited alongside technical phrasing.