How we rank Biology

Guess papers claim to know which topics will be on your exam. That's not possible for Cambridge International: the board designs its papers to test almost the entire syllabus every series. Across the subjects we've measured, between 86% and 95% of syllabus content is tested each sitting (89% for 9709 Mathematics). So instead of guessing which topics appear, we ran the test guess papers never do — see below.

What genuinely varies from series to series is how many marks each topic is worth. That's what we rank: mark share measured from verified past papers, combined with how ready you are on each topic — so you revise where the marks are, not where you'd guess a topic might appear.

Limitations

• Mark share is measured from a limited number of past series per subject — it gets more reliable as more series are added, not less.
• A topic's mark share is typically what it has been worth, not a guarantee for the next sitting — any single topic can be worth more or fewer marks than its measured average.
• Ranking by weight is one input; your own mastery matters at least as much, which is why the study plan combines both.