top of page


Getting 700+ on the SAT Bio Subject Test


The SAT II Biology E/M test is a multiple-choice test administered by College Board. It is composed of 80 questions that test your knowledge in biology. The test is graded on a scale from 200 to 800 and lasts for 60 minutes. Students majoring in fields that are related to biology usually take the test to show the level of their proficiency in biology. However, any student can take the test even if their desired major is unrelated to biology, but it is highly recommended. The Biology E/M is different from other subject tests administered by College Board because it allows the test-takers to choose one of two sub-fields in biology to focus on, Molecular biology and Ecological biology. With that said, all test-takers have to be prepared for both because they will be tested on both. There are 60 general biology questions that are a mixture of molecular and ecological biology. The last 20 questions, however, are specific to the chosen focus by the test taker. The average score for Molecular biology is 630 and the average score for Ecological biology is 591.


Difference between Molecular and Ecological tests:



The molecular test focuses on evaluating the proficiency of the students in biochemistry (Photosynthesis, Cellular respiration, and Cellular Structures) and the central dogma of biology (DNA transcription and mRNA translation). The ecological test focuses on population studies, taxonomy (classification), energy flow, animal behavior, and ecosystems. Test-takers should study for both, but it is recommended that they dedicate more time on the chosen sub-field as the last 20 questions of the test are specific to the chosen subfield. Test-takers are asked to choose prior to beginning the test itself, but it actually depends on how strict the test center is. Depending on your test center, you can browse both sections of the test and see which is easier for you and this can give you an advantage. However, even though College Board says that you can take multiple subject tests on the same day, you can't take both the Molecular and Ecological test on the same day.


Mathematical questions:


There are questions that require mathematical calculations regardless of the chosen subfield. In molecular biology, test-takers are expected to be able to calculate the probability of inheriting certain traits, understand enzyme kinematics, and comprehend graphs showing genetic variance and other similar topics. In ecological biology, test-takers are expected to understand predator-prey trends and relationships, predict population trends, calculate energy loss between different trophic levels. However, it should be noted that calculators are not allowed because all of the calculation involved in the test are fairly simple numerical calculations.


Lab-oriented questions:


There are questions that will present the test-takers with the setup of a certain biological experiment with the results. These questions will ask the test-takers to explain these results in the context of their prior knowledge. These questions will also ask the test-taker to explain possible alternative outcomes for the same experiment. Test-takers will also be asked to evaluate the experimental setup followed (e.g. bad control parameters). These questions differ from other questions because they require test-takers to incorporate their knowledge on a variety of topics in biology in order to answer them adequately.


Good starting points for preparation (Personal Experience):


Barron's SAT Subject Test Biology E/M:


If the test-taker is already familiar with the content of the test, then it is a good

starting point for reviewing the content of the test. It provides a generalized

explanation to the content tested on. From my experience I found that this book

assumes previous competency over the content of the test. It is good for reviewing,

but not for understanding the content from scratch.


Kaplan's SAT Subject Test Biology E/M:


It provides a sufficient and concise explanation for test-takers who lacked prior

knowledge. So it is a good starting point for the test-takers who lack understanding

of the content. Alternating between the two previous books is also a good tactic

because there are specific details present in one but not the other. For example,

Barron's contains a section about allergies, something which Kaplan's only briefly



Princeton's SAT Subject Test Biology E/M:


It provides a lengthy explanation for all the content to be tested on. It excels over other preparation books in terms of practice questions. The questions presented in it are actually from previous tests and are very similar to the actual test questions. Thus, it provides an adequate representation of the actual test which makes for good practice.


 Other resources for in-depth understanding of content:


A useful resource I found for test-taker willing to deeply understand the content is the E-Z Biology guide. It provides lengthy explanations for the concepts tested on and a wealth of questions following each section. Khan academy website is also another useful resource for test-takers, especially for those who choose Molecular biology. It provides the visual aid necessary to truly understand complex processes that involve DNA replication/transcription and Photosynthesis/Cellular respiration.



 Study and test-taking strategies:


In all of the previous guides mentioned above, there are practice questions after each section. It is highly recommended to solve these questions because they measure your mastery of each specific section and allow you to pinpoint your weaknesses. Additionally, in the end of each guide there are full practice tests that emulate the actual test. It is also recommended to tackle these tests while timing yourself and setting in a quiet place to simulate the actual test day. The test-taker should also realize that he or she doesn't need to answer all of the questions in the test to get the 800 mark. In fact, each wrong question deducts 1/4 of a point from your score, but an omitted question doesn’t add or remove points from your score. Moreover, the test-taker doesn’t need to go through all of the content to get a 700+ mark. Here is a breakdown of the questions in the test:


Cellular and Molecular Biology: Cell structure and organization, mitosis, photosynthesis, cellular respiration, enzymes, biosynthesis, biological chemistry


• Biology E: 12 questions

• Biology M: Approximately 21- 22 questions


Ecology: Energy flow, nutrient cycles, populations, communities, ecosystems,

biomes, conservation biology, biodiversity, effects of human intervention


• Biology E: Approximately 18-19 questions

• Biology M: Approximately 10-11 questions


Genetics: Meiosis, Mendelian genetics, inheritance patterns, molecular genetics,

population genetics


• Biology E: 12 questions

• Biology M: 16 questions


Organismal Biology: Structure, function, and development of organisms (with

emphasis on plants and animals), animal behavior


• Biology E: 20 questions

• Biology M: 20 questions


Evolution and Diversity: Origin of life, evidence of evolution, patterns of evolution,

natural selection, speciation, classification and diversity of organisms


• Biology E: Approximately 17-18 questions

• Biology M: 12 questions



Good luck

*These numbers may vary on an annual basis as College Board modifies and changes their test constantly, but they should provide adequate insight as to what to expect in the test.

bottom of page