2 Biology resources Search within results Go How ratings and recommendations work Apply Filter resourcesClear all filtersLevel A2/A-level GCSE SubjectClear filter Biology Exam board AQA OCR TopicClear filter Specialised exchange surfaces Resources Crossword Flashcards Multi-tool Quizsearch Revision Notes Gaseous exchange surfaces A2/A-level, Biology Crossword Specialised exchange surfaces GCSE, Biology Revision notes Search again