Hello everyone! I am a high school student from a public school in China applying to US universities. Since my intended major is biology-related, I took the USABO and BBO competitions in 11th grade, along with the AP Biology exam in the same year. I achieved a Global Gold award in the BBO and a score of 5 in AP Biology. Today, I would like to introduce the BBO and share my preparation experience.
BBO Competition Overview
The British Biology Olympiad (BBO) is one of the longest-running and most influential science competitions for high school students in the UK. Nearly 10,000 high school students participate annually. The awards carry significant weight and are highly regarded, placing the BBO alongside the USABO as one of the most prestigious theoretical biology competitions. It was introduced to China by ASDAN in 2016.
Registration Method
Partner schools register students collectively through the ASDAN platform.
Exam Date (Based on Previous Years)
Saturday, January 17, 2026, 14:00–15:30 (90 minutes)
Registration Deadline (Based on Previous Years)
January 6, 2026
Awards & Scoring
Gold, Silver, Bronze, Highly Commended, and Commended awards are first determined by the scores of UK students, with cutoffs set at the top 5%, 15%, 30%, 45%, and 60% respectively. Scores for students from other countries are not ranked proportionally; instead, they are directly compared against these UK cutoff lines to determine eligibility and award levels.
Chinese students generally perform exceptionally well, and the award rate is slightly higher than that of UK students.
BBO Exam Scope
- 20% Cell Biology: Microbiology, biotechnology, cell structure and function (chemical composition, organelles, protein synthesis, mitosis and meiosis, cell metabolism).
- 20% Animal Anatomy and Physiology (emphasis on vertebrates): Digestion and nutrition, circulation, reproduction and development, regulation (nervous and hormonal), respiration, excretion, immunity.
- 15% Plant Anatomy and Physiology (focus on seed plants): Photosynthesis, transpiration and gas exchange, transport of water, minerals, and assimilates, growth and development, reproduction (including ferns and mosses).
- 5% Ethology (Animal Behavior): Behavioral systems, conflict behavior, etc.
- 10% Ecology: Ecosystems, biogeochemical cycles, population structure and dynamics, etc.
- 5% Taxonomy: Evolutionary and ecological relationships among typical species, etc.
- 20% Genetics and Evolution: Variation, Mendelian genetics, multiple alleles, recombination, sex linkage, etc.
Below is the official English syllabus for your reference:
BBO Official Syllabus
The competition consists of two, one-hour multiple choice papers to be taken online under exam conditions (supervised, invigilated test centre).
Questions in the BBO are largely based on the A-level syllabus, but the competition also aims to stretch students by including a number of questions that test problem solving skills and understanding of basic biological principles.
Topics covered may include:
- Cell Biology: Structure and function of cells, Microscopy, Cell division
- Animal Anatomy and Physiology: Structure and function of the major organ systems, Homeostasis, Coordination and response
- Plant Anatomy and Physiology: Structure and function of roots, stems and leaves, Transport in plants, Reproduction in flowering plants
- Ecology: Ecosystems, Biodiversity and conservation, Nutrient cycles
- Inheritance: DNA and the genome, Inheritance, Variation and evolution
- Biochemistry and Microbiology: Biological molecules, Enzymes, Microorganisms and their applications
- Techniques: Experimental design and data analysis, Use of appropriate units and standard form
The BBO is based on the A-level curriculum but also includes university-level concepts beyond the standard syllabus, requiring a solid foundation in biological knowledge.
BBO vs. AP/A-level Biology
The requirements and content scope of the competition are higher than those of standardized exams. Therefore, preparing for the competition will essentially cover the exam points of standardized tests and help you memorize concepts and terminology in advance.
Taking the AP exam as an example, the AP Biology syllabus below shows significant overlap with the BBO.
AP Biology Exam Content
- Unit 1: Chemistry of Life - 8-11%
- Unit 2: Cell Structure and Function - 10-13%
- Unit 3: Cellular Energetics - 12-16%
- Unit 4: Cell Communication and Cell Cycle - 10-15%
- Unit 5: Heredity - 8-11%
- Unit 6: Gene Expression and Regulation - 12-16%
- Unit 7: Natural Selection - 13-20%
- Unit 8: Ecology - 10-15%
Since the BBO is held in early April and the AP Biology exam is in early May, I prepared for the BBO first. After mastering the competition material, the AP exam felt much less complex.
BBO vs. USABO
The two biology competitions cover similar content, and many students interested in biology choose to register for both. I highly recommend taking them together!
However, each competition has distinct characteristics. During the intensive practice phase, you can focus on the one that aligns best with your strengths. Here are some key comparisons:
Commonalities
- Both test professional theoretical knowledge in biology and require a strong foundational understanding.
- The exam time is tight, demanding high reading comprehension and reaction speed: BBO is 90 minutes for 70-90 questions (with a record of 135 questions in 2022); USABO is 50 minutes for 50 questions.
Differences
- Focus of Assessment: BBO tends to directly test knowledge points, assessing familiarity and quick recall. It includes many chart analyses, image identification, and material analysis questions closely tied to everyday life. USABO places a higher demand on reasoning skills and the flexible application of knowledge.
- BBO generally has shorter question stems compared to USABO. USABO provides more background context and tests knowledge in greater detail.
- Last year, BBO offered a Chinese version, significantly reducing the difficulty of memorizing specialized biological terminology.
Study Timeline
Since the BBO is based on the A-level syllabus, it is best to have a comprehensive understanding of the entire system before starting preparation (refer to the official BBO syllabus above). Due to the extensive content, many students choose to start preparing from September to October of the previous year. This allows for a steady, thorough review of all material. Students with a stronger foundation may opt to start around November.
By December, you can begin intensive practice with past papers to familiarize yourself with the exam style and recurring topics.
BBO Preparation Timeline
- September-October: Start preparation, build knowledge system
- November: Continue learning, consolidate foundation
- December: Begin intensive practice with past papers
- January: Final review and mock exams before competition
Participants' starting levels vary, so adjust accordingly. However, those aiming for top awards are strongly advised to start early!
For example, I only began preparing in mid-February 2021, leaving less than a month and a half before the exam. I immersed myself in biology daily, maintaining a heavy workload while reviewing basics and practicing simultaneously. Despite having some foundation from domestic biology competitions, I had to sacrifice many other opportunities. Therefore, it is crucial to start early and prepare systematically!
My Experience
In this section, I will detail my BBO preparation methods. The process can be divided into building a knowledge system, supplementing knowledge, practicing while summarizing, and timed practice. However, since everyone's background differs, these are just suggestions. Adapt them to your own situation!
1. Build a Knowledge System
I highly recommend Campbell Biology! It is organized by chapters (e.g., Chemistry and Cells, Genetics, Evolution, Plant Form and Function), providing a clear knowledge structure. Additionally, it features high-quality illustrations to aid memory and offers extension content that can supplement classroom learning. Beginners to biology competitions should study it thoroughly.
Given the volume of material, create a study plan based on the syllabus and study with varying levels of detail. It might feel challenging at first due to the English text and length, but persistence pays off!
Reading Campbell Biology also helps you directly encounter and memorize English terminology, which is crucial for the BBO and other exams (AP/A-level/USABO). Moreover, tackling biology textbooks will naturally improve your English reading proficiency!
2. Supplement Knowledge
Based on your foundational knowledge, take notes according to the syllabus and your personal needs. Biology covers so much that without notes, it is easy to forget! (Trust me, I often forgot earlier topics while learning new ones.)
For example, in the 20% Animal Anatomy and Physiology section, Cellular Respiration is a key topic that requires repeated review and frequently appears on exams. You can summarize its 3 stages (Glycolysis; Citric Acid Cycle/TCA Cycle/Krebs Cycle; ETC/Oxidative Phosphorylation, noting that slashes indicate alternative names), the inputs and outputs of each stage, and where each occurs in the cell.
Cellular Respiration Summary
- Stage 1: Glycolysis
Location: Cytoplasm
Input: Glucose, 2 ATP, 2 NAD+
Output: 2 Pyruvate, 4 ATP (net 2 ATP), 2 NADH - Stage 2: Citric Acid Cycle / TCA Cycle / Krebs Cycle
Location: Mitochondrial matrix
Input: 2 Acetyl-CoA, 6 NAD+, 2 FAD, 2 ADP
Output: 4 CO2, 6 NADH, 2 FADH2, 2 ATP - Stage 3: Electron Transport Chain (ETC) / Oxidative Phosphorylation
Location: Inner mitochondrial membrane
Input: 10 NADH, 2 FADH2, O2
Output: 32-34 ATP, H2O
3. Practice While Summarizing
Once you have accumulated sufficient knowledge, start working through past papers. You must summarize your mistakes and review them repeatedly. Ensure you fully understand any question you initially got wrong or could not solve. Consult teachers or search for explanatory videos on platforms like Bilibili or YouTube.
I recommend adding unfamiliar concepts to your notes for two reasons: First, key topics recur frequently, so mastering them early saves time later. Even if questions are rephrased, careful reading and logical deduction will help. Second, summarizing mistakes expands your knowledge base. The BBO heavily tests deductive reasoning. As a science subject, biology rewards repeated thinking, which sharpens your mind and builds a snowball of knowledge.
Using Cellular Respiration as an example again, when you think of it, you can also connect it to how C4 plant respiration differs from standard plants, how CO2 is stored, and typical examples of C4 plants.
4. Timed Practice
Initially, you may struggle with time limits, but as you master the content and question formats, your speed will naturally increase. At this stage, begin timed practice to simulate real exam conditions.
Practice Tips
- Start with untimed practice to build accuracy
- Gradually introduce timing (e.g., 1 minute per question)
- Simulate exam conditions with full 90-minute sessions
- Review all mistakes carefully
- Focus on speed without sacrificing accuracy
Students with a solid biology foundation may also choose to learn directly through practice. Identify frequently tested topics from past papers and focus your studies there. However, building a systematic knowledge base and mastering exam points remain the most reliable paths to high scores!
Competition Features
In my opinion, the defining feature of the BBO is its broad content coverage. Like most theoretical biology competitions, it spans all major fields of biology (see the syllabus above). It demands significant knowledge accumulation and memorization, meaning the preparation cycle is relatively long and requires consistent review. However, once you are familiar with the material, answering questions becomes much easier.
Recommended Resources
Campbell Biology
Ideal for building a comprehensive knowledge system. It contains extensive material, and electronic versions are widely available online. Minor variations may exist between editions.
Campbell Biology Details
- Recommended for: Building comprehensive knowledge system
- Features:
- Clear chapter organization (Chemistry and Cells, Genetics, Evolution, Plant Form and Function, etc.)
- High-quality illustrations for visual learning
- Extension content beyond basic curriculum
- Direct exposure to English biological terminology
- Improves English reading proficiency
- Note: Available in electronic versions on various websites; minor differences may exist between editions
BBO Past Papers
You can search for them online. If you enroll in a prep course, instructors will usually provide them.
Bilibili
Video platforms make biology concepts highly engaging. When encountering difficult topics, search for them directly. Many videos offer detailed explanations. Some recommended creators include Osmosis (Chinese), Fangstafu, and Biochemistry Online.
YouTube
Functions similarly to Bilibili. Since the content is in English, it also helps familiarize you with the pronunciation and usage of biological terms.
That concludes my sharing! I believe that with persistent effort, you will definitely achieve your desired results!
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