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A Field Guide to AP and SAT Biology Tests


In junior year of high school, most students become keenly aware of the wide array of tests available for them to take, either for college admissions or for college credit. Surrounded by a whirlwind of acronyms, it is easy to assume that two tests on the same academic subject would be very similar. Indeed, the AP Biology and SAT Subject Biology exams cover much of the same course material. However, the two tests are distinct in emphasis and structure, and they require different mindsets on test day.

AP vs. SAT

The tests’ most obvious differences are in their structure. The SAT Subject Biology test is entirely multiple choice, with 5 answers to each question and a 1/4 point penalty for incorrect answers. It is very fast-paced, with 80 questions in 60 minutes.

The AP exam, in contrast, is much slower-paced but longer, with 63 multiple-choice questions and 6 numerical grid-in questions in 90 minutes, and then another 90 minutes for 8 free response questions. There are only 4 answers to each multiple-choice question and no penalty for incorrect answers.


It is important to be aware of these differences while taking the tests, as they determine how long it is reasonable to spend on each question and under which circumstances it is advisable to guess when stuck. Generally, even in the SAT Subject test, if some of the answers can be eliminated as clearly incorrect, then guessing when stuck is statistically beneficial.

The presence of free-response questions in the AP is also a major difference because these questions require a mindset that is different from how students should approach multiple-choice questions. In general, graders of free-response questions look for a specific array of potential answers, and in some cases two very different answers can be considered correct so long as the student properly explains the one he or she chooses to write about.


Student Studying


The tests are also somewhat different in content. Although the topics they cover overlap, their focuses are different. The SAT Subject Biology test is heavy on memorization and vocabulary, while the AP Biology exam puts a greater emphasis on scientific method, experimental design, and theory. There are still vocabulary questions in the AP exam and experimental questions in the SAT Subject but fewer than in their counterparts.

In addition, due to the greater emphasis on mathematics in the AP exam, students taking that test are allowed a simple calculator and given a formula sheet for reference, while no such materials are permitted in the SAT Subject Biology test. Mathematical concepts common in the AP Biology exam include graph reading, probability, the chi-square test, and understanding exponential growth.

One topic that often comes up regarding the SAT Subject biology exam is the difference between Bio-E (Ecology) and Bio-M (Molecular). These two tests are delivered in the same packet and share the first 60 questions of the test, only branching into two sections for the last 20. Students do not have to register for them separately and, in theory, could choose which one to take as late as the day of the exam itself. At AJ, we encourage students to try out both as part of the preparation process, and then pursue whichever one they score higher on.

It is certainly possible for a student who is proficient in biology to take both the SAT Subject Biology and the AP Biology exams with knowledge of much of the same academic content. However, being aware of the differences between the tests, becoming familiar the different techniques needed to tackle them, and studying with practice tests of both varieties will give students the best chance of success.

Our tutors have expertise and experience with both exams, so please reach out to us to learn more about how AJ can help your student.


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