IB Biology SL Grade Boundaries 2025: Complete Breakdown

4 min read

Introduction

The IB Biology SL course develops conceptual understanding, analytical thinking, and practical investigation skills. Success requires knowing how each assessment contributes to the final grade—and understanding the grade boundaries set by the IB.

In this guide, you’ll find the complete grade boundary ranges for IB Biology SL in 2025: Paper 1 (MCQ), Paper 2, Paper 3, Practical Work, and the final overall grade boundaries. Plus, tips to maximize your score and achieve a 7.

Quick Start Checklist for IB Biology SL

  • ✅ Memorize the grade boundary ranges for each component.
  • ✅ Focus on key concepts and their applications.
  • ✅ Practice multiple-choice, data analysis, and extended-response questions.
  • ✅ Complete practical work thoroughly and document results.
  • ✅ Review examiner reports to understand expectations for top grades.

IB Biology SL Grade Boundaries 2025

Paper 1 (MCQ) (out of 30)

  • Grade 7: 24–30
  • Grade 6: 20–23
  • Grade 5: 17–19
  • Grade 4: 13–16
  • Grade 3: 11–12
  • Grade 2: 8–10
  • Grade 1: 0–7

Paper 2 (out of 50)

  • Grade 7: 39–50
  • Grade 6: 33–38
  • Grade 5: 26–32
  • Grade 4: 20–25
  • Grade 3: 12–19
  • Grade 2: 6–11
  • Grade 1: 0–5

Paper 3 (out of 35)

  • Grade 7: 25–35
  • Grade 6: 21–24
  • Grade 5: 18–20
  • Grade 4: 14–17
  • Grade 3: 9–13
  • Grade 2: 5–8
  • Grade 1: 0–4

Practical Work (out of 24)

  • Grade 7: 20–24
  • Grade 6: 17–19
  • Grade 5: 14–16
  • Grade 4: 11–13
  • Grade 3: 7–10
  • Grade 2: 4–6
  • Grade 1: 0–3

Final IB Biology SL Grade Boundaries (out of 100)

  • Grade 7: 76–100
  • Grade 6: 64–75
  • Grade 5: 52–63
  • Grade 4: 40–51
  • Grade 3: 26–39
  • Grade 2: 14–25
  • Grade 1: 0–13

Tips for Scoring in the Top Grade Ranges

  • Paper 1 (MCQ): Practice timed multiple-choice questions and focus on essential terminology.
  • Paper 2: Review command terms and practice data analysis and extended-response questions.
  • Paper 3: Master experimental design and evaluation questions.
  • Practical Work: Maintain thorough lab notes, analyze data carefully, and reflect on methods.

Why RevisionDojo Gives You an Edge

RevisionDojo provides targeted IB strategies to improve performance in all Biology assessments. From conceptual understanding to practical and exam techniques, it helps students achieve higher scores efficiently.

Frequently Asked Questions (FAQs)

1. Why are grade boundaries different for each paper?

Each assessment emphasizes different skills—conceptual knowledge, data analysis, extended responses, and practical skills. Boundaries reflect difficulty and historical performance data.

2. How much does each assessment impact my final grade?

All components contribute to the final mark out of 100. Weakness in any area can lower your overall grade even if other components are strong.

3. Which assessment is considered the most challenging in SL?

Many students find Paper 3 difficult due to experimental design and evaluation questions. Regular practice and familiarity with past papers can make it manageable.

Conclusion

Success in IB Biology SL requires strong conceptual understanding, practical skills, and exam strategies. Knowing the exact grade boundaries allows students to plan effectively, set goals, and maximize their final grade.

RevisionDojo provides guidance and strategies to help students achieve their best results efficiently.

Grade Boundaries at a Glance (IB Biology SL 2025)

Paper 1 (MCQ) (30)
7: 24–30 | 6: 20–23 | 5: 17–19 | 4: 13–16 | 3: 11–12 | 2: 8–10 | 1: 0–7

Paper 2 (50)
7: 39–50 | 6: 33–38 | 5: 26–32 | 4: 20–25 | 3: 12–19 | 2: 6–11 | 1: 0–5

Paper 3 (35)
7: 25–35 | 6: 21–24 | 5: 18–20 | 4: 14–17 | 3: 9–13 | 2: 5–8 | 1: 0–4

Practical Work (24)
7: 20–24 | 6: 17–19 | 5: 14–16 | 4: 11–13 | 3: 7–10 | 2: 4–6 | 1: 0–3

Final Grade (100)
7: 76–100 | 6: 64–75 | 5: 52–63 | 4: 40–51 | 3: 26–39 | 2: 14–25 | 1: 0–13

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