Biology (5090) Topic 9 · Human gas exchange 9.1 Human gas exchange Practise the structure of the gas-exchange system, ventilation, alveolar adaptations, gas diffusion, and the effects of exercise and smoking. Key TheoryLearn FirstLoading… Common MistakesAvoid TheseLoading… StrategyApply ThisLoading… Practice 1EasyLoading… Practice 2EasyLoading… Practice 3MediumLoading… Practice 4MediumLoading… Practice 5MediumLoading… Practice 6AdvancedLoading… Practice 7AdvancedLoading… Practice 8AdvancedLoading…