Biology and medicine-related majors are among the most popular and competitive fields for international students applying to top universities. As a result, many applicants try to demonstrate their academic interests and potential in these areas through various activities and achievements.

One effective way to strengthen an academic profile is by participating in high-level biology competitions.

Among them, BBO (British Biology Olympiad) and USABO (USA Biology Olympiad) are widely recognized as two of the most prestigious competitions in the field of biology. They are particularly popular among students in grades 9–12 who plan to apply for majors such as biology, medicine, biochemistry, or psychology.

In previous years, these two competitions were usually held on the same day. However, BBO has been scheduled earlier this year, leaving USABO as the major biology competition taking place in April.

What exactly does the competition test? How difficult is it? And how should students prepare? Let’s take a closer look.

Part 1: Who Should Participate in the USABO?

The USABO (USA Biology Olympiad) is organized by the Center for Excellence in Education (CEE) and is considered one of the most academically rigorous and influential science competitions in the United States. In China, it is also commonly referred to as BIO-USACN.

Students who perform well in USABO are often recognized by prestigious universities such as Tsinghua University, Peking University, Harvard University, Stanford University, Columbia University, and the University of Cambridge.

Eligibility

Officially, the competition is open to high school students of any grade. However, due to its high level of difficulty and strong academic focus, it is generally recommended for students who:

• Have a solid foundation in general biology

• Have previously taken biology competition courses

• Possess strong independent learning abilities

Many educators recommend that 11th-grade students participate, as the exam requires a comprehensive understanding of advanced biology topics, and preparation can be demanding.

Students who are particularly interested in biology, medicine, biochemistry, neuroscience, or psychology will benefit the most from participating in this competition.

2026 USABO Key Dates

• Registration Deadline: March 24, 2026

• Competition Date: April 4, 2026

• Exam Time: 10:30–11:20 (50 minutes)

• Registration Location: School testing centers or authorized institutions

Exam Format and Awards

Exam Format

• Individual competition

• 50 multiple-choice questions

• Total score: 50 points

• Exam duration: 50 minutes

Award Categories

• Gold Medal: Top 10% of total scores

• Silver Medal: Top 25%

• Bronze Medal: Top 35%

• Regional Honorable Mention: Top 20% within each region (excluding national award winners)

Part 2: How Difficult Is the USABO?

Distribution of Exam Topics

The USABO covers a wide range of biology topics with the following approximate weight:

• 20% Cell Biology

• 15% Plant Anatomy and Physiology

• 25% Animal Anatomy and Physiology

• 5% Animal Behavior

• 15% Genetics and Evolution

• 15% Ecology

• 5% Taxonomy

Competition Difficulty Comparison

Breadth and Depth of Knowledge

• Breadth of topics: USABO ≈ BBO

• Depth of knowledge: USABO > BBO

Among several major biology competitions, the difficulty ranking in terms of conceptual depth is generally considered:

USABO > BBO > Brain Bee

In terms of academic level, these competitions roughly correspond to:

• USABO: A2 level

• BBO: AS level

• Brain Bee: IGCSE level

Question Format and Volume Comparison

Number of Questions

• BBO: More questions than USABO

• USABO: Fewer questions but higher difficulty

BBO

The BBO exam often includes data analysis, image interpretation, and real-world biological scenarios. The number of questions has increased in recent years:

• Around 70–90 questions in earlier exams

• 135 questions in 2022

• 168 questions in 2023

The exam duration is typically 120 minutes, and the question count continues to rise.

USABO

The USABO exam contains 50 multiple-choice questions completed in 50 minutes. While the format appears simple, the difficulty level is among the highest in biology competitions, requiring students to integrate knowledge across multiple biological fields.

Because of the exam’s difficulty, scoring around 50% may already be enough to reach the gold medal range, which typically represents the top 10% of participants.

However, many students miss an award by only one or two questions, which makes solid mastery of core knowledge especially important.

Part 3: Final Preparation Before the Exam

As of January 13, there were 81 days remaining before the 2026 USABO competition, making it the ideal time to begin structured final preparation.

An effective exam preparation strategy should include:

1. Focused review of key concepts across the main biology topics tested in the exam.

2. Practice with past competition questions to develop familiarity with the question style and difficulty level.

3. Full-length mock exams and post-test analysis to identify knowledge gaps and improve accuracy under time constraints.

With systematic preparation, students can significantly improve their performance and increase their chances of earning a medal in the USABO competition.