What's the Best Way to Revise for IB Biology?

Active recall beats rereading every time — close the book, write everything you remember about a subtopic, then check it against the syllabus. Pair that with timed past paper questions marked strictly against the official mark scheme. I've watched students jump a grade in one term just by switching from highlighting notes to this cycle.

You don't memorise Biology by reading it five times — you memorise it by testing yourself on it. Use spaced repetition flashcards (Anki or paper) for definitions and named examples, and diagram recall for processes like the light-dependent reactions. Revisit each card at increasing intervals: day 1, day 3, day 7, day 21.

There's no single number that fits every student, but as a working guide: 3-4 hours a week outside class from the start of DP2, rising to 6-8 hours weekly in the two months before mocks and finals. Short, focused 45-minute sessions with a clear goal beat one unfocused three-hour block every time.

Paper 3 tests the options and data-based/experimental-design skills, so revise it differently from Papers 1 and 2. Practise reading unfamiliar graphs and tables under time pressure, and drill the command terms 'suggest', 'identify a trend' and 'evaluate the method' — these carry specific mark-scheme wording examiners look for.

IB Biology has a reputation as one of the more content-heavy DP sciences — there's simply more to learn than in Physics, though the maths demand is lower. HL adds eight Additional Higher Level (AHL) topics on top of the core, roughly doubling the syllabus content students need to hold in memory for exams.

HL Biology is harder mainly because of volume, not difficulty of individual ideas — you cover the same core syllabus as SL plus eight AHL topics (2.2, 3.2, 4.2, 5.2, 6.2, 7.2, 8.2, 9.2) and sit an extra, longer Paper 2 section and a longer Paper 3.

Grade boundaries shift every exam session because they're statistically set against that cohort's performance, not fixed in advance. As a rough historical guide, a 7 has typically needed somewhere around 80-85% of total available marks across Papers 1-3 combined — but always check the actual boundary document for your session.

Your final Biology grade combines three timed written exams (Papers 1, 2 and 3) worth 80% at SL and roughly 76% at HL, plus the Internal Assessment — a single scientific investigation worth 20% at SL and 24% at HL, marked against five official criteria.

Usually it's because 'revising' means rereading notes rather than testing recall under exam conditions — that builds recognition, not retrieval. If you can recognise an answer when you see it but can't produce it cold on a blank page, you're not actually improving, you're just getting more familiar with your own notes.

The data booklet (permitted in all three papers) has formulae, the genetic code table, and other reference data you're not expected to memorise — but only if you already know where to find each item and when it applies. Practise using your actual data booklet during every past paper attempt, not just in the real exam.

It depends on your child's strengths and university plans, not which is 'easier' — Biology rewards strong recall and written explanation, Chemistry demands more calculation and abstract reasoning. For medicine, biosciences or psychology routes, Biology is usually the more directly relevant choice; for engineering or physical sciences, Chemistry often fits better.

Most UK medical schools ask for Chemistry plus one other science at HL — Biology is commonly accepted and often preferred, but check each university's entry requirements directly since they do vary. Some universities accept SL Biology if HL Chemistry and another HL science are present, so don't assume HL Biology is compulsory everywhere.

IB Biology (especially HL) generally covers more breadth than A-Level Biology and adds the Internal Assessment as a compulsory, externally-moderated component — A-Level typically leans more on depth within fewer topics and doesn't usually carry an equivalent independent-investigation weighting of 20-24% of the final grade.

The single best resource is the current IB Biology guide itself (first exams 2025) alongside real past papers marked against official schemes — everything else should build on those. Beyond that, look for topic-organised revision notes, a large question bank sorted by syllabus subtopic, and topical worksheets that isolate one AHL topic at a time.

Costs vary hugely by provider and region, so there's no single reliable figure to quote — what matters more for most families is whether a resource is organised by the current syllabus and includes markable past paper practice, since that's what actually moves a grade, not the price tag alone.