Competitions · Biology · BBO
BBO, the British Biology Olympiad.
Ninety minutes, no practical, and a published syllabus that tells you exactly how many marks each branch of biology is worth. Running since 1995, and the paper that selects Britain’s team for the international olympiad.
At a glance
What the olympiad is, and how it is sat.
BBO is one of the longest-running school science competitions in Britain, entered by close to ten thousand UK students a year. ASDAN China brought it to the China region in 2016; by 2020 students from 243 international and key schools were entering.
- Since
- 1995
- Organiser
- UK Biology Competitions, a registered charity, under the Royal Society of Biology - headquartered in London, with more than 16,000 members across 100-plus countries
- Who can enter
- Students at high school
- Format
- Individual, written. There is no practical examination
- Duration
- 90 minutes
- How it is sat
- Online or in person. Online candidates need a computer with a camera and a mobile device; in-person candidates sit at a centre school in one of four China regions - East, Central-West, South and North
- Language
- The online paper may be answered in Chinese or English
- Equipment
- A simple non-programmable calculator and a paper English-Chinese dictionary are permitted
- When
- A Saturday in mid-January for the China region. The source notes that the organiser’s site and the China-region site publish different dates, and that the China region follows the latter
- Results
- About six to eight weeks after the paper
- Entry fee
- Free for schools in the UK. £30 per school elsewhere, paid to the organiser
- Where it leads
- Selection of the British team for the International Biology Olympiad
The syllabus
Seven areas, and the weight of each is published.
This is the most useful thing on the BBO source page. Most biology competitions publish a topic list; BBO publishes what each topic is worth, which turns revision planning into arithmetic rather than guesswork.
| Area | Weight | What it covers |
|---|---|---|
| Animal anatomy and physiology | 25% | Emphasis on vertebrates: digestion and nutrition, circulation, reproduction and development, regulation by nerves and hormones, respiration, excretion, immunity |
| Cell biology | 20% | Microbiology, biotechnology, cell structure and function - chemical composition, organelles, protein synthesis, mitosis and meiosis, cell metabolism |
| Genetics and evolution | 20% | Variation, Mendelian inheritance, multiple alleles, recombination, sex linkage |
| Plant anatomy and physiology | 15% | Seed plants especially: photosynthesis, transpiration and gas exchange, transport of water, minerals and assimilates, growth and development, reproduction including ferns and mosses |
| Ecology | 10% | Ecosystems, biogeochemical cycles, population structure and dynamics |
| Animal behaviour | 5% | Behavioural systems, conflict behaviour |
| Taxonomy | 5% | Evolutionary and ecological relationships between representative species |
The weights sum to exactly 100. Animals and cells together are 45% of the paper; behaviour and taxonomy together are 10%. A student with limited time now knows where to spend it.
How awards are decided
The thresholds are set in Britain, then applied to everyone.
BBO uses the same absolute-threshold mechanism as several British papers on this site, and it works in the entrant’s favour.
Five bands, set on British students
Gold, Silver, Bronze, Highly Commended and Commended are drawn at roughly the top 5%, 15%, 30%, 45% and 60% of British nationals’ scores.
Everyone else is measured against the mark
Students from other countries are not ranked into a proportion. Their scores are compared directly against the thresholds those bands produced.
Which means no cap on the China region
A strong cohort does not compete against itself for a fixed number of medals. If many students clear the gold line, many receive gold.
And it protects the British field too
The organisers state the reason plainly: overseas entrants do not affect the award proportions or the teaching order in British schools.
Cut-offs
The published thresholds, and why they cannot be compared.
These are the marks each band has required. Read them within a year, not across years - the figures move between three quite different scales, which means the paper’s maximum has changed more than once.
| Year | Gold | Silver | Bronze | Highly Commended | Commended |
|---|---|---|---|---|---|
| 2026 | 225.33 | 211.17 | 200.5 | 192.67 | 185 |
| 2025 | 108.89 | 98.69 | 91.37 | 85.82 | 80.86 |
| 2024 | 113.20 | 103.30 | 96.05 | 90.68 | 86.09 |
| 2023 | 106.64 | 98.43 | 91.72 | 86.69 | 81.96 |
| 2022 | 118.35 | 105.15 | 94.62 | 87.98 | 82.34 |
| 2021 | 63 | 57 | 53 | 47 | 44 |
| 2020 | 51 | 46 | 43 | 37 | 33 |
Gold has been 51, then 63, then a run near 110, then 225. A threshold cannot quadruple on a paper of fixed length, so the maximum mark has changed between these years. Set a target from the award proportions - top 5% for gold - rather than from any figure in this table.
What the paper is like
Broad, visual, and heavy on vocabulary.
The organisers describe the difficulty as moderate overall, with specific places where it is not.
Most of it sits on school biology
A large share of the questions can be answered from a solid high-school course. The paper is built on the A-Level biology syllabus as its foundation.
But it goes wider and deeper than A-Level
The organisers say so directly. Breadth beyond the school course is what separates the top bands, not additional difficulty in familiar topics.
Picture questions are the specific difficulty
Specimen identification from photographs - sometimes of unusual plants and animals - is named as the hardest part. It is also the part school teaching prepares for least.
And the vocabulary load is real
Data and analysis questions require confident biological terminology. A student who knows the biology in Chinese but not the English terms will lose marks they have already earned.
Preparation
How Hanlin prepares students for BBO.
A published weighting and a published threshold mechanism make this one of the most plannable science papers on the site.
Revising to the weights
Animals at 25% and cells at 20% carry nearly half the paper. Preparation is allocated in proportion rather than evenly across seven areas.
Drilling specimen identification
The picture questions are the named weak point and the one school courses do not cover. Practice works through image sets rather than text.
Building the English terminology
Because the paper may be answered in Chinese but is set in English, the terms have to be secure in both. This is the cheapest set of marks to protect.
Reading past the syllabus
The organisers name the standard texts - Campbell’s Biology, Alberts’ Molecular Biology of the Cell, Brooker on genetics, Vander on human physiology, Raven on plants. The top bands come from reading beyond the course.
Why Hanlin
Hanlin has been entering students for BBO for years, and publishes what they got. The record is further down this page.
Programme formats
Five ways this is taught.
Group size is the whole difference between these. It decides how much of the tutor's attention a student gets and how far the course can bend to them, so it is worth choosing rather than accepting.
| Format | Group size | What it suits |
|---|---|---|
| One-to-one | One student | Content, pace and emphasis set by what this student actually needs rather than by a syllabus. The only format that can be rebuilt mid-course. |
| Small group | Three to eight | Opens at three. Frequent discussion, and the tutor can slow down or move on according to what the group has absorbed. Most students chasing a higher award are taught in this one. |
| Class | Eight to twelve | Taught by the subject lead or a medal coach. Less back-and-forth, so it suits a student who will say when something is unclear. |
| Large class | Ten to twenty | For students in the middle of the placement range, and a way to try a competition before committing. Students often move to a small group or to one-to-one afterwards. |
| Past-paper class | No cap | Past papers worked through in sequence in the weeks before the sitting. Free to students already enrolled. |
Course tiers
Which course, and on what evidence.
Every tier for BBO is entered from a placement paper rather than from a year group. These are the actual standards.
| Course | Hours | Who it is for |
|---|---|---|
| Full course | 60 hours | IGCSE biology behind you and eight to fourteen correct on the placement paper |
| Intensive | 40 hours | AS, AP or IB DP1 biology and more than fourteen correct |
| Sprint | 20 hours | Revision and past papers before the sitting |
Ask for the placement paper before choosing a tier. It takes an hour and it settles the question.
How it runs
Six steps, four people on your side.
The same process for every student, so that nothing depends on one tutor remembering to do it.
Step 1Pre-course assessment
A placement paper before anything is booked, so the course tier is chosen on evidence rather than on a year group.
Step 2Tutor matching
A subject tutor is matched to the result, and their full background is provided before you agree to it.
Step 3Plan and group
A study group opens with four people on one student: the tutor, a planner, a supervisor and an academic manager.
Step 4Scheduled teaching
The teaching office sets the timetable around the competition date and school term, and teaching begins.
Step 5After-class reports
What was covered, and how the student handled it, reported after every lesson.
Step 6Homework follow-up
The teaching assistant and the form teacher both check that homework is done, which is where most preparation quietly fails.
Free resource pack
BBO past papers and preparation pack
The same material our own BBO students work from. Scan the code, say what you need, and an advisor sends it.
Tell an advisor which competition and year group, and the material comes back the same day. Free, and you do not have to enrol in anything. If we do not already hold what you need, we will go and find it.
- PDFPast British Biology Olympiad papers with answer keys
- PDFThe syllabus mapped against A-Level and IB biology
- PDFHow BBO and USABO overlap, and how to prepare for both at once
- PDFRegistration checklist and the dates for the current cycle
Teaching team
Who would teach it.
Three of the twenty-two tutors on the published Hanlin roster - the ones whose subject this is.
Yu
Master's in bioinformatics and computational biology from UT Dallas and a nutritional sciences degree from Wisconsin-Madison. Second author on an SCI-indexed paper from the Tanumihardjo vitamin-A laboratory, and formerly at ABS Global.
Zhang
Master's in cognitive science at UC San Diego on full scholarship, after double honours in neurobiology and behaviour and in cognitive science at UC Davis. Ten years overseas, a perfect TOEFL speaking score, and named an outstanding education scholar at UCSD.
Li
Biology at Emory, biomedical engineering at Georgia Tech, and a bioengineering master's at the University of Pennsylvania. College Board-accredited, teaching from a cross-disciplinary research base and folding research practice into the classroom.
Student results
What Hanlin students got.
Taken from Hanlin's published record of student honours and rewritten in English. Figures are as the organisers reported them.
Took Gold in both BBO and USABO, 2025
One line from Hanlin's published BBO record. The rest of it is below.
BBO
- 202544 Gold, 56 Silver and 41 Bronze. 19 students took Gold in both BBO and USABO
- 202491 Gold, 60 Silver and 36 Bronze, with 19 double Golds
- 202349 Gold and 20 double Golds
Earlier years
- 202251 Gold and 27 double Golds
- 20216 Gold, including the first and third placed students nationally
The full record, across every subject and year, is on the student honours page.
Where it is taught
Hanlin learning centres.
Teaching runs from Hanlin's own centres in Shanghai, Shenzhen, Chengdu and Hangzhou, and online for students elsewhere.
Talk to an advisor
Everything Hanlin does for BBO, in one conversation.
Entry, planning, coaching and the past papers. An advisor will tell you which of these a student actually needs, including when the answer is none of them.
Competition entry and planning
Which competitions suit this student, in what order, and by when - then we handle the registration, including the ones that can only be entered through a school or a centre.
Competition coaching
Taught by full-time subject tutors, on a course tier chosen by placement paper rather than by year group.
International curriculum tutoring
IB, AP, A-Level, IGCSE and the US high school curriculum, taught alongside school and timed around the exam calendar.
Competition past papers, free
A large library of past papers, mark schemes and syllabus breakdowns across every competition on this site. No charge and no enrolment.
Scan to add an advisor
Say which competition or course you are asking about. Replies in Chinese or English.
Or call +86 21 6352 6630FAQ
BBO, briefly answered.
What students and families ask before entering.
Who can enter BBO?
High-school students. There is no qualifying paper - entry is direct, through a school or through the China-region organiser.
What is the paper?
A 90-minute individual written paper. There is no practical examination.
Can I sit it online?
Yes. Online candidates need a computer with a camera and a mobile device. In-person candidates sit at a centre school in one of four China regions.
Can I answer in Chinese?
The online paper may be answered in Chinese or English. The questions themselves require confident English biological vocabulary either way.
What may I take in?
A simple non-programmable calculator and a paper English-Chinese dictionary.
How are the medals decided?
Gold, Silver, Bronze, Highly Commended and Commended are drawn at about the top 5%, 15%, 30%, 45% and 60% of British nationals’ scores. Students from other countries are measured against those marks rather than ranked into a proportion, so a strong overseas cohort is not capped.
What does the syllabus cover?
Seven areas with published weights: animal anatomy and physiology 25%, cell biology 20%, genetics and evolution 20%, plant anatomy and physiology 15%, ecology 10%, animal behaviour 5%, taxonomy 5%.
What is the hardest part?
Specimen identification from photographs, including unfamiliar plants and animals. It is the section school biology prepares for least.
What does it cost?
The paper is free for schools in the UK. Schools elsewhere pay £30 per school to the organiser.
When do results come out?
About six to eight weeks after the paper.
Related
Other biology contests.
What students commonly enter alongside or after BBO.
BBO enquiries
The syllabus tells you where the marks are.
Very few competitions publish what each topic is worth. BBO does, which means a preparation plan can be built rather than guessed at. Tell us the student’s year group and what biology they have covered, and an advisor will map the January entry.