C4.2.15—Primary production
Primary production explains how energy flow, matter cycling, trophic transfer or carbon movement is represented, measured or limited within ecosystems.
- Syllabus
- First assessment 2025
- Objective
- C4.2.15
- Level
- HL
Exam analysis
Chance of appearing4%of analysed past papers
Latest appearanceMay 2023
Most common paperPaper2
Typical marks1–3
Common command terms
- State
- Identify
- Compare
- Calculate
- Distinguish
- Annotate
- Describe
- Explain
- Evaluate
Scoring notes
- Common mistake
- Confusing gross production with net production after respiration losses.
Recent exam appearances
May 2023Paper2 ["HL"] · TZ11(g)[ 3 ]C4.2.15—Primary production
May 2023Paper2 ["HL"] · TZ11(e)[ 1 ]C4.2.15—Primary production
May 2023Paper2 ["HL"] · TZ11(d)(ii)[ 2 ]C4.2.15—Primary production
November 2021Paper2 ["HL"] · TZ01(e)[ 3 ]C4.2.15—Primary production
May 2014Paper3 ["HL"] · TZ211(b)[ 1 ]C4.2.15—Primary production
Practice this objective
Coverage 2012–2023 · Updated 16 Jul 2026
Concept essentials
- Primary production must be linked to the correct source, store, transfer or loss process.
- The evidence for primary production depends on distinguishing energy flow from matter cycling.
- Primary production is clearer when arrows, units and trophic positions match the biological process.
- Data or diagrams for primary production need interpretation as ecosystem transfer evidence.