FOR TEACHERSAre you an IB teacher? Apply to teach on Sev7n — or enrol in the IB Teaching Methodology Programme (IBTMP).

Apply to teach →Explore IBTMP

Student LMS ↗

IBDP · May 2026 Exam Prediction

IB Biology HL & SL

Topic Prediction Guide

Paper 1A (MCQ) · Paper 1B (Data) · Paper 2 (Extended Response) — subtopic frequency for IBDP May 2026. Based on May 2025 + 6 years of mapped old syllabus data.

6+

Years Data

40+

Subtopics

4

Themes A–D

HL&SL

Both Levels

Predictions are based on historical past-paper frequency analysis (May 2021–2025) and are a study aid — not leaked or guaranteed exam content.

Ref	Theme	Topic / Subtopic	M20	M21	M22	M23	M24	M25★	HL only?	May 2026
IB BIOLOGY — PAPER 1A MCQ TOPIC FREQUENCY \| May 2025 + Mapped Old Syllabus 2019–2024 \| SL & HL
Free preview: Theme A · Themes B–D locked below · 🟢 = new syllabus · 🟡 = mapped old data · HL-only rows greyed in SL view
THEME A: UNITY & DIVERSITY — cells, classification, viruses, biodiversity (free preview)
A.1	Unity/Div	Cell structure — prokaryotic vs eukaryotic, organelles, ultrastructure, scale & magnification 🟡	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
A.2	Unity/Div	Classification & diversity — binomial nomenclature, phylogenetic trees, kingdoms, domains 🟡	✔	—	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐
A.3	Unity/Div	Viruses — structure, lytic & lysogenic cycles, HIV, COVID, virus-host interactions 🟢	—	—	—	—	—	✔★	SL&HL	⭐⭐⭐⭐ NEW
A.4	Unity/Div	Conservation of biodiversity — species richness, ecosystem services, threats, conservation strategies 🟡	✔	✔	—	✔	—	✔★	SL&HL	⭐⭐⭐⭐
A.HL	Unity/Div	Cladistics & gene pools — cladograms, shared derived characteristics, species concepts, speciation HL 🟢	—	—	—	—	—	✔★	HL	⭐⭐⭐⭐ HL NEW

Ref	Theme	Topic / Subtopic	M20	M21	M22	M23	M24	M25★	HL only?	May 2026
THEME B: FORM & FUNCTION — membranes, proteins, enzymes, cell specialisation
B.1	Form/Func	Membranes & transport — fluid mosaic model, osmosis, active/passive transport, endocytosis	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
B.2	Form/Func	Proteins — structure (primary to quaternary), enzymes, induced fit, inhibition, denaturation	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
B.3	Form/Func	Organelles & specialisation — mitochondria, chloroplasts, cell differentiation, stem cells	✔	✔	—	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
B.4	Form/Func	Gas exchange & transport — lung structure, haemoglobin, heart, blood vessels, stomata, transpiration	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
B.HL	Form/Func	Chemical signalling — hormones, receptor proteins, signal transduction cascades, gene expression HL	—	—	—	—	—	✔★	HL	⭐⭐⭐⭐ HL NEW
THEME C: INTERACTION & INTERDEPENDENCE — ecosystems, homeostasis, immunity
C.1	Interact	Ecosystems — food chains/webs, energy flow, trophic levels, ecological pyramids, succession	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
C.2	Interact	Cycling of matter — carbon cycle, nitrogen cycle, water cycle, decomposition, global warming	✔	✔	✔	—	✔	✔★	SL&HL	⭐⭐⭐⭐
C.3	Interact	Defence & immunity — innate vs adaptive immunity, antibodies, vaccinations, autoimmunity, allergens	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
C.4	Interact	Homeostasis — thermoregulation, blood glucose (insulin/glucagon), osmoregulation, kidney structure	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
C.HL	Interact	Nervous system & muscle — neurones, synapses, action potential, reflex arcs, muscle contraction HL	—	—	—	—	—	✔★	HL	⭐⭐⭐⭐ HL
THEME D: CONTINUITY & CHANGE — DNA, genes, cell division, evolution (most tested overall)
D.1	Continuity	DNA & RNA — structure, complementary base pairing, replication, transcription, translation	✔	✔	✔	✔	✔	✔★★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
D.2	Continuity	Cell division — mitosis stages, meiosis, crossing over, non-disjunction, cancer	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
D.3	Continuity	Inheritance — Mendelian genetics, dihybrid crosses, sex linkage, codominance, ABO blood groups	✔	✔	✔	✔	✔	✔★★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
D.4	Continuity	Natural selection & evolution — Darwin, variation, adaptation, speciation, evidence for evolution	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
D.HL	Continuity	Epigenetics & gene regulation — methylation, histone modification, lac operon, gene expression control HL	—	—	—	—	—	✔★	HL	⭐⭐⭐⭐ HL NEW

Theme	Topic Area	M21	M22	M23	M24	M25★	Avg Marks	May 2026
IB BIOLOGY — PAPER 2 EXTENDED RESPONSE TOPIC FREQUENCY \| May 2025 + Mapped 2019–2024
Extended questions demand multi-theme synthesis \| Command words: explain, evaluate, discuss, compare \| HL-only rows greyed in SL view
THEME D — Most extended Paper 2 marks (DNA/Genetics always tested deeply)
D.1+D.2	Molecular biology extended — DNA structure, replication, transcription + translation as one linked question	✔	✔	✔	✔	✔★★	12–18	⭐⭐⭐⭐⭐ CERTAIN
D.3	Genetics problems — dihybrid cross, linkage, sex-linked traits, pedigree analysis with explanation	✔	✔	✔	✔	✔★★	10–16	⭐⭐⭐⭐⭐ CERTAIN
D.4	Evolution extended — natural selection mechanism, evidence, Hardy-Weinberg, speciation	✔	✔	—	✔	✔★	8–12	⭐⭐⭐⭐
THEME B — Proteins, enzymes and cell function
B.2	Protein structure + enzyme function extended — lock-and-key vs induced fit, inhibition types, denaturation	✔	✔	✔	✔	✔★	10–14	⭐⭐⭐⭐⭐
B.3+B.4	Cell specialisation + physiology — stem cells, differentiation, gas exchange systems, haemoglobin dissociation	✔	—	✔	✔	✔★	8–12	⭐⭐⭐⭐
THEME C — Ecosystems, homeostasis, immunity
C.1+C.2	Ecology + biogeochemical cycles — energy loss in trophic levels, carbon cycle analysis, human impact	✔	✔	✔	✔	✔★	10–16	⭐⭐⭐⭐⭐
C.3	Immunity extended — antibody production, B and T cells, vaccination, clonal selection, HIV mechanism	✔	✔	✔	—	✔★	8–12	⭐⭐⭐⭐⭐
C.4	Homeostasis extended — negative feedback, insulin/glucagon pathway, kidney structure + function	✔	✔	✔	✔	✔★	10–14	⭐⭐⭐⭐⭐
HL topics	Chemical signalling, nervous system, epigenetics, cladistics — HL extended questions always include these HL	—	—	—	—	✔★	10–16	⭐⭐⭐⭐⭐ HL

About the new IB Biology syllabus

IB Biology was restructured for first assessment in May 2025. The old 11-topic syllabus has been replaced by 4 conceptual themes (Unity & Diversity, Form & Function, Interaction & Interdependence, Continuity & Change) with 40+ subtopics. Paper 3 is gone. Options (Neurobiology, Biotechnology, Ecology, Human Physiology) are removed, with some content integrated into HL core.

HL vs SL key differences

›Paper 1: SL = 30 MCQ / HL = 40 MCQ
›Paper 2: SL = 50 marks / HL = 80 marks
›HL additions: Cladistics · Chemical signalling · Nervous system & muscle · Epigenetics · Advanced genetics
›Hours: 150 SL vs 240 HL

Want expert IB Biology tutoring?

Sev7n tutors specialise in the new 2025 Biology syllabus. We know every theme, every HL extension.

Explore IBDP tutoring