Exam skills
What the paper asks you to do
- Write balanced word equations
- Compare yields without unsupported numbers
- Explain exercise-related changes
Human systems
Respiration
Distinguish aerobic and anaerobic respiration and explain why cells require controlled energy release.5090 syllabus routeConcept · skill · exam language
What to know
Build the topic around four anchors.
- 01Aerobic respiration
- 02Anaerobic respiration
- 03Energy uses in cells
- 04Oxygen debt and exercise
Common mistakes
Where marks disappear
- Calling respiration breathing
- Saying energy is created
- Using the plant anaerobic products for muscle cells
Structured practice
Answer these without looking back.
For each prompt, write the biological chain clearly enough that every mark-worthy link is visible.
- 01Compare aerobic and anaerobic respiration.
- 02Explain why breathing remains fast after exercise.
- 03State three cellular uses of energy.
Continue learning
Read the connected explanation.
Trace carbon, electrons and energy through glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation.
This independent teaching resource follows the Cambridge O Level Biology 5090 syllabus direction and is not endorsed by Cambridge International Education.