IB Biology M26: What Actually Changed (2025+) and How to Use Old Past Papers Correctly

If you are M26 and asking whether old Biology papers are still useful, the right answer is:

Yes, but only if you adjust for the 2025+ structure changes.

Most advice misses this. Students are told to "just do more past papers" without being told which parts of old papers no longer match current assessment design.

This guide is the practical version.

The Real Changes (Old vs New)

1) External exam structure changed

First assessment 2016 model (old):

• Paper 1 (MCQ): 20%
• Paper 2: 40% (SL) / 36% (HL)
• Paper 3: 20% (SL) / 24% (HL)
• Options were examined in Paper 3 section B.

First assessment 2025 model (current):

• Paper 1: 36%
  • Paper 1A (MCQ)
  • Paper 1B (data-based, four questions)
• Paper 2: 44%
• No Paper 3

What this means in practice:

• Data interpretation pressure moved into core papers.
• You cannot prep as if there is a separate option-driven Paper 3 safety net.

2) Options were removed from the course model

Old structure used:

• Core + AHL + one option (A/B/C/D).

New structure uses:

• themed syllabus organization (A/B/C/D strands), with selected content integrated into the main course model.

Practical implication:

• Old option-heavy practice is lower priority unless it clearly transfers to current paper skills.

3) Paper 1 is no longer "MCQ-only"

Old:

• Paper 1 was straightforward MCQ only.

Now:

• Paper 1A = MCQ, but Paper 1B is data-based and explicitly linked to experimental work + syllabus themes.

Practical implication:

• "I can do MCQs so I’m fine" is no longer enough.
• Students who ignore Paper 1B-style data reasoning usually underperform relative to predicted.

4) IA assessment rubric changed in a way students feel immediately

Old IA criteria (2016 guide):

• Personal engagement
• Exploration
• Analysis
• Evaluation
• Communication

New IA criteria (2025 guide):

• Research design
• Data analysis
• Conclusion
• Evaluation

Each is weighted evenly (6 marks each, total 24).

Practical implication:

• The rubric is now more explicitly methodological and evidence-focused.
• Students relying on "good narrative + neat write-up" without strong method/data logic are exposed faster.

5) IA formatting expectations changed

Old subject brief language referenced a write-up of 6 to 12 pages.

Current model specifies:

• one scientific investigation report,
• maximum overall word count of 3,000 words.

Practical implication:

• You must write tightly and evidence-first.
• Long unfocused write-ups are actively punished by time pressure and rubric precision.

So... Should M26 Students Use Old Past Papers?

Yes, but use this decision rule.

Keep old questions when they train current high-value skills:

• data interpretation,
• command-term precision,
• short-answer structure,
• extended-response reasoning.

Use cautiously when they are highly tied to removed option framing.

Skip when they are format-specific to what no longer appears in your current exam pathway.

That is the difference between efficient prep and fake productivity.

Expert Revision Priority for M26 Biology

If your exam is close, prioritize in this order:

1. Paper 1B-style data-based work
2. Paper 2 short answers (precision + clarity)
3. Paper 2 extended responses (argument quality)
4. Paper 1A MCQ speed/accuracy
5. Legacy-paper selective drills only for transferable skills

Most students do #4 first because it feels easier. The scoring upside is usually in #1 and #2.

Markscheme-Level Mistakes I See Repeatedly

These are the recurring losses that matter under the new structure:

1. Data question answered from memory, not from the figure/table.
2. "Explain" answered like "define" (no causal chain).
3. Extended response gives facts but not a balanced biological argument.
4. IA conclusions not explicitly tied back to processed data + uncertainty.
5. IA evaluation gives generic limitations, not method-specific impact.

Fix these, and grades move.

A Better Way to Use Old Papers (Without Wasting Time)

Before each old question, ask three things:

1. Does this map to Paper 1A/1B/2 skill demands?
2. Does it train command-term execution I still need?
3. Will correcting this error improve a markscheme outcome this week?

If the answer is no, skip it.

That is not laziness. That is exam intelligence.

If You’re 2-4 Weeks Out

Do not run random full-paper marathons. Run targeted cycles:

1. timed data-based block,
2. correction + rewrite block,
3. timed short-answer block,
4. correction block,
5. one extended response with strict self-marking.

Repeat.

If you want a cleaner workflow, run it directly in Marksy Past Papers and pair with IB grade boundaries context when setting score targets.

Final Answer to the Original Question

Yes, use old papers.

But stop using them as if nothing changed.

The students who adapt to:

• Paper 1A + 1B,
• Paper 2-heavy weighting,
• no Paper 3/options exam dependency,
• the new IA rubric logic,

are the students who convert effort into marks fastest in M26.

Sources

• IB Diploma Programme Subject Brief: Sciences: Biology—Standard level, first assessments 2016 (IBO, 2014): old assessment model + options structure + IA write-up format.
• IB Diploma Programme Subject Brief: Sciences: Biology, first assessment 2025 (IBO, 2022): current structure (Paper 1A/1B, Paper 2, IA weighting).
• IB Biology Guide, first assessment 2025 (published Feb 2023, updated Mar 2024): external assessment details, IA criteria framework, command-term expectations.
• IB Biology Guide, first assessment 2016: legacy paper structure and legacy IA criteria framework.

Related Reading and Useful Tools

• How to Use IB Past Papers to Improve Faster (Without Burning Out)
• How to Study for IB Exams: The Ultimate Revision Guide
• Creating Study Schedules That Actually Work for IB
• IB Grade Boundaries Explained: What You Need to Know
• Practice IB Past Papers
• Get Rubric-Aligned Grading Feedback
• Browse all IB blog articles