What B/B actually tests
B/B covers biology and biochemistry, with organic and general chemistry in supporting roles. It is the most experiment-driven section: passages routinely present novel studies, and the questions test whether you can connect your content knowledge to data you have never seen before.
Pure recall questions exist, but the section's center of gravity is application: reading a figure, tracking an experimental design, and reasoning one step past what the passage states.
Reading a 123 honestly
A 123 in B/B is in the 32nd percentile on the official AAMC section table, in the broad middle of the 118 to 132 scale. Section scores here are common, and what they mean depends on the company they keep: a 123 next to three stronger sections reads differently than a 123 in a balanced line.
For a Retaker, a middle section score is often the best value target on the whole score report, because moving it usually requires refining execution rather than relearning a subject from scratch.
How Retakers move this section
B/B improvement on a retake tends to come from practicing the passage-to-question connection rather than re-watching content videos. If your content base held up, the leverage is in experimental reasoning and figure literacy.
The B/B Section Bank is the best official window into that skill, with the Biology Question Packs providing the volume work underneath it.
Common questions
Is a 123 B/B score good?
A 123 in B/B is in the 32nd percentile on the official AAMC section table, meaning 32% of section scores were equal to or lower. Whether it is strong enough depends on your total score, your section balance, and your target programs.
What percentile is a 123 in B/B?
On the AAMC section percentile table in effect May 1, 2026 to April 30, 2027, a 123 in B/B is in the 32nd percentile.
How do Retakers improve B/B?
B/B improvement on a retake tends to come from practicing the passage-to-question connection rather than re-watching content videos. If your content base held up, the leverage is in experimental reasoning and figure literacy.
See the fuller picture
Section scores only mean something in context. For scale, a 123 across all four sections would land near a 492 total. Compare nearby B/B scores: a 122 in B/B and a 124 in B/B, or see how a 123 reads in the other sections: C/P · CARS · P/S.
For a personalized read on your whole score report, start with the free Retaker Calculator, and when you are ready to build the plan, The Retaker Course schedules your B/B work for you.