IB Biology SL · 2025
3.9 Transfers of energy and matter
18 past paper questions from 10 papers across 3 exam sessions. See what repeats, then practise the same skills with AI marking.
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SL archive · from 2025
3.9 Transfers of energy and matter
Latest exam session: November 2025
- questions
- 18
- questions
- papers
- 10
- papers
- exam sessions
- 3
- exam sessions
- micro-topics
- 6
Micro-topics in 3.9 Transfers of energy and matter
In syllabus order. The ring is the share of papers each appears in.
3.9.1
Modes of nutrition & autotrophs vs heterotrophs
5 questions · in 42% of papersAppears in 5 of the 12 Biology SL papers analysed (42%), at least once each.
Frequently testedlast Nov 25 P2 TZ3
3.9.2
Food chains, food webs & trophic levels
4 questions · in 33% of papersAppears in 4 of the 12 Biology SL papers analysed (33%), at least once each.
Frequently testedlast Nov 25 P1 TZ1
3.9.3
Energy losses & pyramids of energy
2 questions · in 17% of papersAppears in 2 of the 12 Biology SL papers analysed (17%), at least once each.
Regularlast Nov 25 P2 TZ3
3.9.4
Pollutants in food chains: bioaccumulation & biomagnification
1 question · in 8% of papersAppears in 1 of the 12 Biology SL papers analysed (8%), at least once each.
Occasionallast May 25 P2 TZ3
3.9.5
4 questions · in 33% of papersAppears in 4 of the 12 Biology SL papers analysed (33%), at least once each.
Frequently testedlast Nov 25 P1 TZ3
3.9.6
Decomposers & nutrient cycling
2 questions · in 17% of papersAppears in 2 of the 12 Biology SL papers analysed (17%), at least once each.
Regularlast Nov 25 P2 TZ3
Exam pattern
How often each micro-topic has been examined, year by year. Each label is explained under the grid.
Does it repeat?
Top 4 of 6 micro-topics for the next sitting. Numbers are questions per year.
fewermore
| Micro-topic | 2025 |
|---|---|
| 5Modes of nutrition & autotrophs vs heterotrophs, 2025: 5 questions | |
| 4Food chains, food webs & trophic levels, 2025: 4 questions | |
| 4The carbon cycle, 2025: 4 questions | |
| 2Decomposers & nutrient cycling, 2025: 2 questions |
2 more micro-topics with a free account
- Frequently testedin at least a quarter of all papers, and still appearing in the last two years
- Regularin roughly one paper in six or more
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Questions on 3.9 Transfers of energy and matter, by exam session
Which papers asked about 3.9 Transfers of energy and matter, and which question numbers. Open a paper to see them highlighted.
November 2025
5 questions across 3 papers
May 2025
8 questions across 6 papers
Specimen 2025
2 questions across 1 paper
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Frequently asked questions
Short answers about this page.
Which Biology SL exam sessions are covered for 3.9 Transfers of energy and matter?
3 exam sessions from 2025, the latest November 2025. Every Paper 1 and 2 in every timezone is read and classified in full, which gives 10 papers in this archive.
Which 3.9 Transfers of energy and matter topic comes up most?
Modes of nutrition & autotrophs vs heterotrophs (3.9.1): in 42% of papers, last seen Nov 25 P2 TZ3. Usually "other", worth about 1 marks in a paper that includes it.
Can I see the original question and mark scheme?
No. The wording belongs to the IB. You get the citation, the marks, the command term and the skill tested, plus our own matched practice questions with worked answers and AI marking.
What do "banker", "due" and "rising" mean?
Banker: examined in at least one sitting in four and still appearing. Due: regular before, but absent for the last two exam sessions. Rising: clearly more common in the last two years. Our classification of real papers, not an IB statistic.
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