C4.2.9—Energy release
Energy release explains how energy flow, matter cycling, trophic transfer or carbon movement is represented, measured or limited within ecosystems.
- Syllabus
- First assessment 2025
- Objective
- C4.2.9
- Level
- HL
Exam analysis
Chance of appearing3%of analysed past papers
Latest appearanceMay 2021
Most common paperPaper1
Typical marks1
Common command terms
- Describe
- Identify
- State
Scoring notes
- Common mistake
- Giving a generic ecosystem answer without the specific transfer or process for energy release.
Recent exam appearances
May 2021Paper2 ["HL"] · TZ24(a)[ 1 ]C4.2.9—Energy release
May 2015Paper1 ["HL"] · TZ214[ 1 ]C4.2.9—Energy release
May 2013Paper1 ["HL"] · TZ229[ 1 ]C4.2.9—Energy release
Practice this objective
Coverage 2013–2021 · Updated 16 Jul 2026
Concept essentials
- Energy release must be linked to the correct source, store, transfer or loss process.
- The evidence for energy release depends on distinguishing energy flow from matter cycling.
- Energy release is clearer when arrows, units and trophic positions match the biological process.
- Data or diagrams for energy release need interpretation as ecosystem transfer evidence.