Exam skills
What the paper asks you to do
- Compare inhalation with exhalation
- Explain alveolar adaptations
- Interpret breathing-rate or volume data
Human systems
Human gas exchange
Use pressure, muscle action and diffusion to explain ventilation and exchange at the alveoli.5090 syllabus routeConcept · skill · exam language
What to know
Build the topic around four anchors.
- 01Airway structure
- 02Ventilation mechanics
- 03Alveolar exchange
- 04Effects of exercise and smoking
Common mistakes
Where marks disappear
- Confusing ventilation with respiration
- Reversing diaphragm movement
- Saying oxygen is pumped into blood
Structured practice
Answer these without looking back.
For each prompt, write the biological chain clearly enough that every mark-worthy link is visible.
- 01Explain inhalation using pressure changes.
- 02Describe three alveolar adaptations.
- 03Interpret breathing data before and after exercise.
Continue learning
Use the complete resource route.
Open the student materials, official syllabus or the next topic in sequence.
This independent teaching resource follows the Cambridge O Level Biology 5090 syllabus direction and is not endorsed by Cambridge International Education.