IB Biology SL Grade Boundaries 2025 TZ2: Breakdown

The week before results, every IB student becomes a part-time statistician.

You replay every silly mistake (the mislabeled axis, the rushed definition, the stubborn multiple-choice guess) and then try to convert anxiety into certainty: What will the boundaries be?

This breakdown is for IB Biology SL Grade Boundaries 2025 (Timezone 2), with a key note many students miss: this is based off November 2024 performance patterns and boundary behavior. It’s the most practical way to set targets when you’re revising, planning mocks, or sanity-checking your progress.

Quick checklist before you obsess over boundaries

Use the boundaries like a map, not a prophecy. Here’s the IB checklist that keeps you grounded:

• Convert your goal (4/5/6/7) into component targets (Paper 1, Paper 2, Paper 3, Practical Work).

• Train each skill type weekly: recall, data handling, long explanations, lab evaluation.

• Track marks, not hours: your IB grade moves when your raw score moves.

• Sit timed practice often enough that pacing stops being a surprise.

• After each attempt, fix one recurring error pattern (not ten).

If you want a fast way to compare boundaries across sessions, keep the IB Grade Boundaries tool bookmarked.

IB Biology SL Grade Boundaries 2025 (Timezone 2): component ranges

A small historical note that matters for context: pre-2025 Paper 3 existed as a familiar component for Biology students, and it still shapes how many students train practical and data skills.

Below are the grade boundary ranges for IB Biology SL 2025 TZ2 by component.

Paper 1 (MCQ) grade boundaries (out of 30)

• Grade 7: 28-30

• Grade 6: 24-27

• Grade 5: 19-23

• Grade 4: 15-18

• Grade 3: 11-14

• Grade 2: 8-10

• Grade 1: 0-7

For Paper 1 training, drill speed + accuracy using a proper IB question source like the RevisionDojo Questionbank and keep an error log.

Paper 2 grade boundaries (out of 50)

• Grade 7: 39-50

• Grade 6: 33-38

• Grade 5: 28-32

• Grade 4: 22-27

• Grade 3: 15-21

• Grade 2: 8-14

• Grade 1: 0-7

Paper 2 is where many IB students lose marks quietly: not from ignorance, but from vague phrasing. RevisionDojo’s IB Biology Paper 1 and Paper 2 guide is helpful for aligning answers to command terms.

Paper 3 grade boundaries (out of 34)

• Grade 7: 27-34

• Grade 6: 23-26

• Grade 5: 18-22

• Grade 4: 14-17

• Grade 3: 9-13

• Grade 2: 5-8

• Grade 1: 0-4

Paper 3 rewards calm experimental thinking: variables, controls, uncertainty, evaluation. If you struggle with data prompts, use a focused explainer like IB Biology Paper 1B: Data-Based Questions to build a repeatable method.

Practical Work grade boundaries (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

Practical Work is where consistent students quietly win in IB Biology: clean processing, sensible graphs, and evaluation that sounds like a scientist, not an apology.

Final IB Biology SL grade boundaries (out of 100)

• Grade 7: 81-100

• Grade 6: 68-80

• Grade 5: 55-67

• Grade 4: 43-54

• Grade 3: 29-42

• Grade 2: 16-28

• Grade 1: 0-15

To sanity-check your current marks against targets, use the IB Grade Calculator.

How to use IB grade boundaries to study smarter (not harder)

Grade boundaries become useful when you turn them into a routine.

• Build understanding fast: use the IB Biology hub to move from Study Notes to questions without switching tabs and losing momentum.

• Lock in recall daily: RevisionDojo Flashcards work best as a 10-minute habit, not a weekend project.

• Convert knowledge into marks: the Questionbank plus AI Chat helps you see why an answer earns 1/2 marks, then rewrite it.

• Simulate pressure weekly: mix Mock Exams with IB Predicted Papers to practice pacing, stamina, and topic coverage.

• Don’t neglect coursework: the Coursework Library and Grading tools help you tighten analysis and evaluation so Practical Work stops being a gamble.

If you want a bigger framework for passing efficiently, read How to Pass IB Biology SL Exams.

Final thought: IB boundaries matter, but your habits matter more

Knowing IB Biology SL Grade Boundaries 2025 (Timezone 2) helps you aim. But the students who end up calm on results day are the ones who built a simple loop: learn with Study Notes, remember with Flashcards, practise in the Questionbank, ask AI Chat what went wrong, then rehearse with Predicted Papers and Mock Exams.

If you want that loop in one place, start with the RevisionDojo IB Biology hub and set your next target using the IB grade boundaries above.