C4.2 Transfers of energy and matter

Transfers of energy and matter connect sunlight, feeding, trophic levels, decomposers, heat loss and carbon cycling to ecosystem structure, function and sustainability.

What you’ll learn

22 learning objectives

Choose one objective for a focused lesson, or study the complete topic.

Exam analysis

An aggregate view of how the complete C4.2 Transfers of energy and matter appears across past papers.

Chance of appearing68%of analysed past papers

Latest appearanceNovember 2025

Most common paperPaper1

Most tested objectives

C4.2.10—Trophic levels38 questions
C4.2.11—Energy pyramids34 questions
C4.2.17—Carbon cycle diagrams31 questions

Common question formats

Calculation
Diagram interpretation
Definition or recall
Comparison
Structured response
Data analysis
Evaluation
Process explanation
Extended response

Exam question appearances

November 2025Paper2 ["SL"] · TZ35(c)[ 3 ]C4.2.12—Energy reductions

November 2025Paper2 ["SL"] · TZ35(b)[ 2 ]C4.2.5—Supply to decomposers

November 2025Paper2 ["SL"] · TZ35(a)[ 1 ]C4.2.6—Autotrophs as self-feeders

November 2025Paper2 ["HL"] · TZ14(b)[ 2 ]C4.2.18—Carbon sinks and sources

November 2025Paper1A ["HL"] · TZ337[ 1 ]C4.2.11—Energy pyramids

Practice this topic

9 original exam-style questions based on the patterns above.

Coverage 2010–2025 · Updated 16 Jul 2026