USABO 2021

Hi guys,

I have noticed that nobody has created the new thread.

What’s new in the 2021 USABO?

All exams will be online at one time and on one day administered by the Art of Problem Solving. Test Administrators will continue to proctor the online exams and are required to complete the Test Administrator Certificate that includes the USABO Honor Code. Students will continue to complete the Student Certificates that includes the USABO Honor Code.Exams will be password protected will be available only at the appointed time and date as indicated on the schedule and will be emailed directly to the students with the student password following.

National Finals
It is anticipated that the 2021 National Finals will be virtual.

Hi! Thanks for creating a new thread for the USABO 2021. Biolympiads is organising a 12-week intensive training course to prepare for the 2021 USA Biology Olympiad (Biolympiad) Competition to be held in early February 2021.

Over the course of 12 weeks, it will cover the most important topics which come up in the USABO exams. The breakdown of topics is:

Cell Biology (30%)
Biochemistry (20%)
Genetics and Evolution (20%)
Plant Anatomy and Physiology (20%) Ecology (5%)
Ethology (5%)

Note that this course will NOT cover Human physiology and Anatomy, Zoology and Biosystematics.

Online lectures will take place every Saturday and Sunday at times to be determined, reading assignments will be provided in advance. In addition, every week students will also receive problem sets and lecture handouts.

This USABO training course provides knowledge from various aspects of biology, therefore, many different textbooks will be used during the classes. All lecture material will be drawn from textbooks listed below. They include:

  1. Cell Biology:
  • Molecular Biology of the Cell by Alberts
  • Lehninger Principles of Biochemistry by Michael Cox
  • Biochemistry by Harvey
  1. Genetics and Evolution:
  • Genetics: Analysis and Principles by Brooker
  • Molecular Biology of the Gene by Watson
  1. Plant Anatomy and Physiology:
  • Biology of Plants by Raven
  1. Ecology & Ethology
  • Campbell Biology by Reece (ch 51-55)

Thanks, Martyna! I joined it and I am really enjoying the camp. So many new things and the curriculum is really rigorous. I am just guessing if the camp is aimed at Semifinal preparation?? Because we study like pKa values and ketogenesis and all of these advanced things that are not in Campbell.

Did anyone else feel that the Practice exam was rough?

yeah it was pretty rough .
What was your score? is there a way to see the score distribution for the practice open?

I got low 20s hbu?

I don’t think there is a histogram

i got 30, but idk if thats good or the test was just relatively easy compared to other years

Were you a semifinalist last year or in the top 50/ top 150?

top 150 yeah


Actually this is the first I am about to take the USABO. My school has registered, I have registered for USABO and for Aops. However, I have never received an email with the passcode for the practice exam.

When was it send and did anybody receive it? Who should I contact for help?


Actually, the mock exam was the 2016 open exam. Here are all past papers: Also on Biolympiads we have just posted a list of tips and tricks how to master the USABO 2021 exam so check it out at USABO 2021 Open Exam Top Tips & Tricks | Biolympiads

Can someone please explain this? I’m losing my mind over it.

Suppose you have solutions of the following amino acids buffered at a pH of 7.0. In which of the solutions would the major species have no net charge? SELECT ALL THAT APPLY.

  1. Histidine (6.0)
  2. Glutamic Acid (4.2).
  3. Cysteine (8.3).
  4. Isoleucine (>14).
  5. Lysine (10.0).

The correct answer is supposedly only #5, Lysine.

To answer this question you need to know the isoelectric point of each amino acid (pH at which the amino acid has no charge). The isoelectric point of lysine is around 10. I wouldn’t worry about questions like these to be honest. Isoelectric points aren’t really worth the effort to memorize ( since there’s 20 of them) and the only way around it is memorizing the isoelectric points of their functional groups which is arguably worse.

I already know how to find the isoelectric point and the charge of amino acids at various pHs. By my calculations, the answer should be a, c, and d at a pH of 7. Like you said, lysine has a pI of about 10, and is neutral between ~9.5-10.5, so how can that possibly be the answer. Lysine should have a +1 charge at a pH of 7, right?

Also this problem is nuts:

Examine the diagram below of a human eye condition. Which of the following statements are TRUE? SELECT ALL THAT APPLY.

  1. Vision may be restored with convex lens and refractive surgery.
  2. Vision may be restored with concave lens and refractive surgery.
  3. This condition often occurs in elderly people.
  4. This phenomenon can be fixed by LASIK (laser-assisted in situ keratomileusis) surgery.

The answers are supposedly #s 1 and 4. I can see 4, but 1 makes no sense. Myopia, which is shown by the diagram, is corrected with a concave lens, not a convex!

Dear all,

Biolympiads is running a preparation course for USABO 2021 Semi-finals. This program consists of 7 weeks of intensive training to prepare students for the USABO 2021 Semifinal exams.

The goal of the Biolympiads Training Program is to prepare highly motivated students to compete in the USA Biology Olympiad (USABO). The students will follow an intensive curriculum prepared by experienced biology olympiad coaches. You will also receive the access to resources of the training course which include:

  • Handouts for each module mentioned above
  • Lecture presentations
  • Weekly quizzes
  • Lecture recordings

Duration: 7 weeks
Schedule: 4 hrs on Saturdays and 4 hrs on Sundays (8 hrs per week)
Class time: 12pm - 2pm EST - Break - 3pm-5pm EST
Course start day: Saturday, 27 February 2021

Over the course of 7 weeks, the training camp will cover the most important topics which come up in the USABO exams. The breakdown of topics is:

  • Human physiology and Anatomy: 30%
  • Cell Biology & Biochemistry: 30%
  • Genetics: 15%
  • Plant anatomy and physiology: 15%
  • Ecology & Ethology: 10%

To find out more, visit https://■■■■■■■■■/EjxngVKeDx6AJzoF6 or

If you have any questions, contact us at

How’d everyone do? Is there anywhere we can see a score distribution? I’ll start: I got 25.

I got 33, I believe the cutoff is 24


We have uploaded the score distribution here: USABO preparation | Biolympiads. Scroll to USABO 2021. :wink: