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Biology EE Criteria Guide

Develop an independent biological question with strong subject knowledge, sharp critical thinking, and disciplined structure.

For assessment in 2027. Submit a single RPF reflective statement of up to 500 words. Use this guide to keep the Biology Extended Essay focused on a precise question, accurate biological terminology, evidence-based analysis, and a polished presentation that supports your argument from start to finish.

Assessment criteria

What each criterion measures, how many marks it carries, and what stronger evidence usually looks like.

Criterion names, marks and mark bands follow the IB subject guide. The band descriptions are our own summaries, so check your subject guide for the exact wording.

Criterion A: Framework for the essay (6 marks)

Use a clear question, suitable research methods and an effective essay structure.

Stronger evidence
A precise, relevant question is supported by well-chosen methods and a structure that makes the research easy to follow.
Early-stage evidence
The question lacks focus or relevance, the methods fit poorly, and the structure does little to help the reader.

Criterion B: Knowledge and understanding (6 marks)

Show subject knowledge through relevant sources, concepts and accurate terminology.

Stronger evidence
A well-chosen body of sources supports strong knowledge, with accurate terminology and effective use of relevant concepts.
Early-stage evidence
The chosen material is weakly relevant, concepts receive shallow treatment, and terminology is sparse or inaccurate.

Criterion C: Analysis and line of argument (6 marks)

Analyse the research and connect the question, findings and conclusions.

Stronger evidence
Effective analysis produces relevant findings, and a sustained argument connects these findings to the question and conclusions.
Early-stage evidence
The essay mainly describes its material and the argument is incomplete.

Criterion D: Discussion and evaluation (8 marks)

Weigh the findings and assess the strengths and limits of the research.

Stronger evidence
A balanced discussion is supported throughout. Relevant strengths and limits are explained when judging the research.
Early-stage evidence
The importance of the findings is described without supporting evidence. Evaluation is incomplete and does not identify strengths or limits.

Criterion E: Reflection (4 marks)

Evaluate what the essay taught you and how that learning transfers to other situations.

Stronger evidence
The reflection evaluates the experience throughout, using examples that consistently show growth and transfer.
Early-stage evidence
The reflection recounts the process without showing how learning could transfer.

Mark bands

Want to know where your EE sits in these bands? Upload your draft and get a mark for each criterion.

Grade my EE

How to build it

Most weak drafts fail on order, not on ideas.

  1. 1

    Lock a narrow question

    Choose a biological topic that is researchable, specific, and clearly linked to the subject.

  2. 2

    Build subject knowledge first

    Use accurate terminology and relevant theory so the essay sounds like biology, not general science.

  3. 3

    Argue from evidence

    Weave findings, comparisons, and evaluation into a coherent line of reasoning instead of stacking summary paragraphs.

  4. 4

    Finish with presentation discipline

    Make the layout, citations, and reflective elements clean enough that the assessment can reward the thinking rather than be distracted by format issues.

Before you submit

  • Research question is specific, focused, and biologically valid.
  • Terminology and concepts are accurate throughout.
  • Evidence is interpreted rather than merely described.
  • The essay is clear. The separate RPF statement evaluates your growth and how you can use what you learned.

Quick wins

  • Draft a one-sentence thesis that answers the question before expanding the essay.
  • Use source notes to separate biological fact, interpretation, and evaluation.
  • Check each paragraph for a clear link back to the research question.

Get Rubric Feedback On Your Biology EE Draft

Upload your Biology Extended Essay draft to Marksy and get criterion-level feedback on research design, subject knowledge, argument, evaluation and reflection. The result includes a mark for every criterion, evidence from your draft, and the changes to make first.

Grade My Biology EESee Pricing
  1. 1

    Upload your EE draft as a PDF

  2. 2

    Get a mark and feedback for every EE criterion

  3. 3

    Revise and grade the new version

A mark for every criterion
A mark for every criterionSee where the draft is now, criterion by criterion.
Comments on your sentences
Comments on your sentencesEach comment points at the passage it is about.
What to fix first
What to fix firstConcrete next edits instead of "improve your analysis".