If you teach IB Diploma Biology, there’s an updated subject guide carrying a first assessment 2028 label — and a brand-new Biology data booklet to go with it. Before you start rewriting your scheme of work from scratch, here’s the reassuring bit: this is a maintenance revision of the existing syllabus, not a new course. The themes, the content and the exams are the same shape you already know. What’s changed is how much students have to carry in their heads — and that’s worth a proper look.

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The headline: Biology finally gets a data booklet

For years, Biology has been the odd one out among the three sciences — Chemistry and Physics candidates have always walked into the exam hall with a data booklet, while Biology students were left to memorise structures, equations and reference data. That ends with first assessment 2028.

The new Biology data booklet contains physiology diagrams, relevant equations, constants and other course-specific data. The important details for planning:

• Students must have access to a copy for the whole course, not just the exam, so they get familiar with it.
• A clean copy is provided in both Paper 1 and Paper 2, at SL and HL.
• The guide makes direct references to the booklet inside the syllabus understandings, so you’ll see exactly which diagrams and equations are now “given.”

The stated aim is to shift the emphasis from memorisation towards interpretation and application — and nearly every other change in the guide flows from that one decision.

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It’s a revision, not a redesign

Worth saying clearly, because the date on the cover can cause panic: the syllabus skeleton is untouched.

• Same four themes (A–D) and the same level-of-organisation structure.
• Exactly the same 549 understandings — nothing added, nothing removed.
• Same command terms (the glossary is identical).

A 2028 cohort sits the same exams, of the same shape, on the same content map as a 2025 cohort. What’s changed is the guidance attached to individual statements.

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What the data booklet changes in the syllabus

The edits to the understandings fall into three clear patterns. These are the ones to mark up in your planning.

1. “Provided in the data booklet” — recognise, don’t reproduce

Around twenty statements now point students to the booklet for a diagram, structure, equation or dataset, with the depth of knowledge adjusted accordingly. The clearest example is the generalised amino acid (B1.2.1):

• Before: students should be able to draw a diagram of a generalised amino acid.
• Now: students should be able to recognise and interpret it — the structure is provided in the data booklet.

That “draw it from memory → recognise and interpret it” shift is the whole philosophy in one statement. The same treatment now applies to things like:

• DNA and nucleotide structures (A1.1.2, A1.2.2)
• Relevant cycle diagrams (A2.3.3–4)
• Examples of fatty acids (B1.1.10)
• The haemoglobin–oxygen dissociation curve (B3.1.13)
• mRNA codon tables (D1.2.9)
• Pedigree symbols (D3.2.13) and box-and-whisker plots (D3.2.15)

2. Scope reductions — less to memorise

A batch of “students are not required to know…” notes trims cognitive load. Among the ones teachers will notice:

• SL students no longer need to know which bases are purines vs pyrimidines (A1.2.4)
• Myoglobin dropped (B3.1.11)
• Symplastic and apoplastic pathways excluded (B3.2.18)
• FAD not required in respiration (C1.2.7, C1.2.12, C1.2.13)
• Detailed T-cell activation mechanisms excluded (C3.2.8)
• lac and trp operon names and mechanisms dropped (D2.2.11)
• Several “historical development” requirements removed (e.g. cell theory, A2.2.1)

3. “Include” became “use” — these examples are now compulsory

This one’s quieter, so don’t miss it. Across roughly a dozen statements (B4.1.2, B4.1.8, C2.1.2, C4.1.12, D3.2.10, D4.2.6 and others), the guidance changed from “include” to “use” or “use examples of.” The purpose is to make clear those named examples are for assessment and must be explicitly taught — not treated as optional illustrations. It’s a tightening, not a loosening.

There’s also one genuine content tidy: at D4.3.10 the great tit / caterpillar-biomass example was removed in favour of a suitable local example.

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What hasn’t changed

So you can stop worrying about the parts that are stable:

• Exams: Paper 1 (1h30, 36%, 55 marks, split 1A/1B), Paper 2 (1h30, 44%, 50 marks, Sections A/B). 80% external, 20% internal, both SL and HL. The only edits to the assessment section are the lines noting data-booklet access (plus “equations are provided in the data booklet” on Paper 1).
• Internal assessment: the scientific investigation is unchanged — still 10 hours, same criteria. The only edit is cosmetic (“IB candidate code” became “candidate’s personal code”).
• Command terms: identical glossary.
• Skills: Tool 3 (Mathematics) gained two bullets about using equations and symbols from the booklet, and a short “Biology data booklet” subsection was added to the skills pages. Otherwise unchanged.

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What to do now

Three practical jobs for updating your planning:

1. Get the data booklet in front of students from day one and teach to it — they need to be fluent with what’s in it well before the exam.
2. Apply the “not required” trims so you’re not teaching depth that’s no longer assessed.
3. Treat the “use”-reworded examples as examinable and make sure they’re explicitly in your lessons.

One caveat: always confirm against the official guide and booklet on the Programme Resource Centre — the documents above are the primary source, and the data booklet is a separate publication you’ll want to read in full.

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📄 Downloads

(Both are also available to teachers on the Programme Resource Centre at resources.ibo.org.)

Have a colleague who teaches the Diploma? Share this with them — the “include → use” change in particular is easy to miss.

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