D4.2.4—Mesocosm model
Mesocosms model ecosystem stability by enclosing simplified communities where matter cycling, energy input, variables, and population changes can be observed.
- Syllabus
- First assessment 2025
- Objective
- D4.2.4
- Level
- SL
Exam analysis
Chance of appearing4%of analysed past papers
Latest appearanceNovember 2024
Most common paperPaper1
Typical marks1–2
Common command terms
- Discuss
- Outline
- State
- Suggest
- Explain
Scoring notes
- Common mistake
- Assuming a sealed mesocosm exchanges no energy, when light or heat can still pass between the system and surroundings.
Recent exam appearances
November 2024Paper1 ["SL"] · TZ118[ 1 ]D4.2.4—Mesocosm model
November 2023Paper1 ["SL"] · TZ218[ 1 ]D4.2.4—Mesocosm model
May 2023Paper3 ["SL"] · TZ23(d)[ 2 ]D4.2.4—Mesocosm model
May 2023Paper3 ["SL"] · TZ23(b)[ 1 ]D4.2.4—Mesocosm model
November 2021Paper1 ["SL"] · TZ017[ 1 ]D4.2.4—Mesocosm model
Practice this objective
Coverage 2018–2024 · Updated 16 Jul 2026
Concept essentials
- A sealed mesocosm restricts matter exchange but can still exchange energy with its surroundings.
- Mesocosms support replication and variable control while preserving some ecological interactions.
- Model limitations arise because natural environments vary more than small enclosed systems.