The Ultimate SAT Biology Subject Test Study Guide


If you're applying to selective schools, you might have to submit SAT Subject Test scores along with your regular SAT (or ACT) scores. The Biology Subject Test (also called Biology SAT II) is a popular one because a vast majority of students take biology in high school, and most students find it less intimidating than chemistry or physics. This test can be a great way to fulfill your Subject Test requirements, especially if you plan on studying biology in college and want to show off your skills.

In this study guide, I'll give you all the background information you need to start studying for the Biology Subject Test as well as example questions, practice materials, and study tips to use along the way.


UPDATE: SAT Subject Tests No Longer Offered

In January 2021, the College Board announced that, effective immediately, no further SAT Subject Tests will be offered in the United States. SAT Subject Tests ended internationally in June 2021. It is now no longer possible to take SAT Subject Tests, including the SAT Biology test.

Many students were understandably confused about why this announcement happened midyear and what this means for college applications going forward. Read more about the details of what the end of SAT Subject Tests means for you and your college apps here.


Biology SAT Subject Test Overview: Format and Test Dates

In terms of Biology SAT Subject Tests, you can choose to take either Biology Ecological (Biology-E) or Biology Molecular (Biology-M). According to the College Board's descriptions of the two SAT Subject Tests, Biology-E "leans more toward biological communities, populations, and energy flow," whereas Biology-M is more "geared toward biochemistry, cellular structure and processes, such as respiration and photosynthesis."

Both versions have the same test format and guidelines:

  • Total Time: 60 minutes
  • Total Number of Questions: 80 multiple-choice questions
  • Scoring: Scored on a scale from 200 to 800
  • No calculator allowed!

Sixty of the questions are identical for both versions of the test, while the last 20 are specialized to either E or M. Biology E/M is offered on the May, June, August, October, November, and December SAT Subject Test dates.


Should You Take the Biology Subject Test? Which Version?

Now that you understand what the Biology SAT Subject Test entails, should you take it or not?

To help you decide, you need to first find out if any of the schools you're applying to require or recommend SAT Subject Tests. You can do this by simply looking at our other article for a full list of schools that ask applicants to send Subject Test scores (we also introduce these schools' specific requirements).

If you already know that you need to take Subject Tests, there are a few reasons you might look to the Biology test as a viable option.



When to Consider Taking the Biology Subject Test

Here are three cases in which it's a smart idea to consider taking the Biology SAT Subject Test.


#1: You Just Took a Biology Class

It's best to take the test in the spring right after you finish a biology course to cut down on study time. Here is the College Board's recommended preparation for the Biology Subject Test:
  • A one-year introductory college preparatory course in biology
  • A one-year course in algebra
  • Laboratory experience

The Biology Subject Test is an especially good idea if you've just taken AP Biology (and have already prepared for the AP test). Subject tests are less intense than AP tests, so in comparison, it will probably seem like a breeze to you.


#2: You Haven't Taken a Science Subject Test

Most colleges that require or recommend SAT Subject Tests are looking for one in the humanities and one in the sciences (except for a couple of outliers such as MIT, which wants math and science Subject Tests).

If you need to take a Subject Test in the sciences and you're nervous about it, Biology is the way to go. It should be slightly easier for you than Physics or Chemistry will be if you're a stronger humanities student. Why? The Biology test involves fewer obscure concepts and calculations, and you can rely slightly more on memorization and basic logic to answer the questions.


#3: You Have a Special Interest in Biology

If you're interested in pursuing biology as a course of study, it's a great idea to take the Biology Subject Test as a way to demonstrate your aptitude for the subject. If you've also done other specialized programs or projects in high school related to biology, taking the Subject Test will only bolster the cohesiveness of your application.


body_backpacker.jpgAlright, let's do this.


Assuming some or all of the factors listed above apply to you, and you've decided to take the test, there's still one more decision to make: Biology E or Biology M?


How to Decide Between the Biology E and Biology M Versions

I gave you a short description of the content of each of these two tests in the previous section, but it probably wasn't enough information for you to make a decision.

This choice ultimately comes down to whether you're more comfortable with the macro or micro aspects of biology. SAT Biology-E deals more with large-scale energy flow in ecosystems and changes in the environment over time. By contrast, Biology M focuses more on the chemical elements of biology that occur on a minuscule scale.

If you're more of a science-oriented student, you'll probably be better off with Biology-M. If you're more into subjects like history and English, Biology-E might be a better choice.

Keep in mind that the two tests aren't completely different. There are only 20 questions out of 80 that are specific to either E or M. For this reason, I wouldn't stress too much over your choice. If you took a biology class and did reasonably well in it, you shouldn't have a problem with either version of the test.

Oh, and for anyone who's wondering—yes, you can take both Biology-E and Biology-M, but you can't take them both on the same test date (makes sense, considering they're almost the same test!).

body_biologym.pngBiology-M is more about this type of stuff. You know—all the creepy things happening at the molecular level inside your body. Right. Now.


What's on the Biology SAT II?

Here's a content overview provided by the College Board that lists the division of topics for each version of the Biology SAT Subject Test:


From the chart, you can see that many more questions are devoted to Cellular and Molecular Biology on the Biology-M test, and many more are devoted to Ecology on the Biology-E test.

Notice that Biology M also has slightly more questions on Genetics, whereas Biology E has slightly more questions on Evolution and Diversity. Both tests have the same number of questions dealing with Organismal Biology. These topics should all be familiar to you if you've taken a biology course.

The types of skills tested on both Biology-E and Biology-M include the following:

  • Recalling fundamental concepts and specific facts (about 30% of test)
  • Applying biological knowledge to practical scenarios presented on the test and solving problems using mathematical relationships (about 35% of test)
  • Making inferences and forming conclusions based on qualitative and quantitative data (about 35% of test)

Essentially, 70% of questions will present a scenario and then ask you to make deductions or calculations based on it. The scenario could be a chart of bacteria growth or a description of a lab procedure. It's important to know the fundamental parts of an experiment (independent and dependent variables) and be able to project your understanding onto unfamiliar situations.

The other 30% of questions just ask you to recall biological facts directly. I'll provide examples of different types of questions you can expect to see on the test in the next section.


body_ecosystem.jpgYou might see questions about changes in species population density in a particular ecosystem. It's the ciiiiiircle of liiiiiiifeeeee!


Biology Subject Test Question Types

Here are a few official examples of the different types of questions you might see on the Biology Subject Test. Each question corresponds to one of the three skills I mentioned above.


Type 1: Data Interpretation


As I mentioned in the previous section, many of the questions on the test ask you to look at data and make deductions from the information given. In this question, although species Y isn't explicitly mentioned in the chart, we know from the background information that whatever percentage of species X is planted, species Y seeds must make up the remainder.

To answer the question, we have to figure out where the graphed line intersects with the line that indicates the 25% mark on the x-axis (that is, the harvest at the point where 25% species X and 75% species Y were planted). It appears that the harvest was 50% species X, which means it must also have been 50% species Y.

Therefore, the correct answer is C.


Type 2: Applying Concepts


In this question, you're asked to apply your biology knowledge to a given situation. Why did the results recorded in the graph occur based on what you know about the experiment?

From the background information (and from studying for the test), we know that thymine is one of the four main nucleotide bases present in DNA. Choice E makes the most sense as an answer to this question because as the embryos develop, they're consistently forming DNA using the radioactive thymine that's available to them.

As I wrote above, you'll also be asked to apply your knowledge of the scientific method and lab procedures to specific scenarios on the test. Take a look at the next question dealing with this radioactivity experiment:


The correct answer is choice C. This would be an appropriate control scenario because RNA contains uracil instead of thymine. The results of the experiment upon adding radioactive uracil would demonstrate definitively that the original experiment measured DNA and not RNA synthesis.


Type 3: Recalling Facts


You'll also see questions like this on the Biology Subject Test that ask you to recall basic facts. The answer to question 1 would be (B), and the answer to question 2 would be (A).

Sometimes these questions are accompanied by diagrams. Here's an example of one in a slightly different format:


This is a little more challenging since you need to identify the parts of the flower that the numbers are labeling and also remember the functions of those specific parts. The answer to question 6 is (A), and the answer to question 7 is (D).


body_flower.jpg10/10 would pollinate.


Where to Find Practice Materials for the Biology Subject Test

If you're looking to prep for the Biology SAT Subject test, you'll need some quality study materials. I've compiled a list of where to find the best practice tests and review guides.


Free Online Sample Questions and Tests

This is a list of online (official and unofficial) practice materials for the Biology E/M Subject Test. Most of these resources don't provide complete practice tests, but there are tons of questions available that will expose you to the full range of the content on the exam.


Official Biology Subject Test Practice Questions

We'll start with the best of the best: official practice questions created by the College Board. All of these questions are extremely realistic and very similar to the ones you'll see on test day.

  • Biology-E: Five questions specific to Biology-E.
  • Biology-M: Five questions specific to Biology-M.


CrackSAT Practice Tests and Questions

Although all of these tests are much shorter than the real thing, they're still incredibly useful as practice materials. Note that since there's less of a focus on lab and data analysis, these questions might be less challenging than those on the actual test.


SAT II: Biology Google Site

This site has two full-length practice tests and two diagnostic tests. It doesn't have automatic scoring since all pages are scanned PDFs, so these are good to print out and take like the real test. Be sure to emulate real testing conditions as closely as possible: follow the official time limit and take them in a quiet room without distractions.


Free Online Content Review

Khan Academy is a free website and partner of the College Board that provides tons of learning materials, including video lessons, practice questions, and answer explanations, for the SAT and various school subjects. Its biology section is especially helpful since it offers an overview of essential concepts, many of which you'll find on the Biology SAT Subject Test.

In addition to in-depth videos that teach you the basic (and even more advanced) biology concepts, Khan Academy offers more than 80 biology practice questions. While these questions don't look like those you'll see on the Subject Test, they're still useful for helping you learn and retain the fundamentals of the subject.


Paid Review Books

In addition to free resources, there are a few helpful review books you can buy that are specifically for Biology E/M. You can also check out this article that focuses on the best books to use for the Biology Subject Test based on your score level.

  • The Official SAT Subject Test in Biology Study Guide: This official book is a must-have. It includes two full-length Biology tests (that were actually administered in the past!) as well as detailed answer explanations and a few test-taking tips. Buy it for around $13 on Amazon.
  • The Official Study Guide for ALL SAT Subject Tests, 2nd Edition: This book contains official practice tests for all SAT Subject Tests, including, of course, the Biology test. It's a good choice if you're planning to take other SAT Subject Tests and prefer having one comprehensive resource. The current price is around $19 on Amazon.
  • Barron's SAT Subject Test Biology E/M, 6th Edition: Although this is an unofficial resource, it's got a lot of material you can work with, including more than 350 questions and two full-length practice tests. It currently sells for about $16 on Amazon.
  • Cracking the SAT Subject Test in Biology E/M, 16th Edition: This book by The Princeton Review aims to get you a perfect 800 on the Biology test. Although its questions aren't as realistic as those in official resources, it does offer a solid array of learning material, from helpful test-taking strategies to practice tests. You can buy it for around $14 on Amazon.


body_croissant.jpgAnd when you're done taking practice tests, you can reward yourself with something that would be unacceptable to consume in public. In the immortal words of the Goo Goo Dolls, "And I don't want the world to see me / 'Cause I don't think that they'd understand / When everything's made to be chocolate / I just want you to know who I am."


How to Study for the Biology Subject Test

Here are a couple of pointers to keep in mind as you study for the Biology SAT Subject Test.


Don't Over-Prepare

Remember that this isn't an AP test—there are no free-response questions, and much of the test involves interpreting information that's already been provided to you. Therefore, if you recently took a final exam for a biology class or the AP Biology test and felt pretty confident about your performance, you shouldn't have any issues acing the Subject Test.

I'd still recommend taking a practice test (as discussed in my next point), but there's no need to kill yourself with studying if the information is fresh in your mind. If it's been a year or so since you took a biology class, a few hours of review might be in order. Again, though, this test shouldn't be especially challenging for you if you've already completed a mid- to high-level biology course.


Take Plenty of Practice Tests

Even if you feel very comfortable with the subject matter, you should take at least one practice test as an experiment to see how high you're scoring. This way, if you're at a satisfactory score level, you can avoid wasting time with additional studying.

If your results are lower than expected, analyze your mistakes and then study the relevant content areas (or just do similar practice problems if your mistakes are related to data interpretation more so than they are to general biology knowledge).

You can also do some practice questions for each version of the Biology test on the College Board website and/or those in the other resources listed above.

body_alert.pngPractice tests can help raise alarms about unexpected problem areas on the test.


Acing the Biology Subject Test: 3 Essential Test-Taking Tips

In this section, I'll give you a few tips for when you actually sit down to take the Biology SAT Subject Test. Tailoring your strategy to the format and content will do wonders for your score!


Tip 1: Read the Background Information—but Don't Overthink It

As you saw from the examples above, questions on the Biology SAT Subject Test often come paired with background information to contextualize the data being provided to you. This will come in the form of a paragraph that describes the experiment so you don't get confused when you look at the corresponding chart or graph. Always take a moment to read this paragraph, as it sometimes contains information that isn't clear if you view the data in isolation.

However, don't get too wrapped up in understanding every aspect of the experiment. It's best to maintain a practical mindset and just focus on understanding the parts you need to know so you can answer the questions.

Take the second sample question above. Here it is again for your reference:


You can see that some of the information in the paragraph—such as the fact that radioactivity was measured in "counts per minute"—doesn't actually help you answer the question.

Be efficient, and avoid dwelling on smaller details that might not be important.


Tip 2: Don't Linger on Hard Questions

As you're taking the Biology Subject Test, you might come across some questions you can't figure out right away. If you spend more than 30 seconds on a question without getting any closer to the correct answer, skip it for the time being and move forward.

Lingering on problems that give you trouble spells danger for this test, so try to answer all the less challenging questions first so you don't run out of time at the end and miss any easy points.


Tip 3: Keep Guessing to a Minimum

Although there's no guessing penalty on the regular SAT, SAT Subject Tests are still under the fractional-point subtraction's reign of terror. This means that guessing incorrectly is worse for your score than leaving a question blank. Answering a question incorrectly on the Biology Subject Test will cause you to lose 1/4 a point, leaving a question blank results in no loss or gain of points, and answering a question correctly earns you one point.

As a result, don't guess on a question unless you can eliminate at least one wrong answer choice. Otherwise, you're taking too much of a risk. If you're completely stumped by a question, just leave it blank.


body_threeoptions.jpgIf you can't decide between five answer options that all seem equally viable to you, leave the question blank.


Conclusion: How to Prep for the Biology SAT Subject Test

The Biology Subject Test can be an easy and convenient way to fulfill your SAT II requirements for college applications. You have the option of taking either Biology-E (ecological) or Biology-M (molecular), but 75% of the questions are the same on both tests.

Both versions of the test are an hour long and include 80 multiple-choice questions that deal with topics ranging from cell biology to genetics to evolution. Though these questions mostly cover basic biology knowledge, there's also a significant amount of data interpretation and analysis of experimental scenarios.

Take a practice test to see where you stand, and do additional studying if you find your knowledge is lacking. If you were successful in your high school biology class, you should generally have no problem doing well on this test with just a little bit of preparation!


What's Next?

Are you currently taking AP Biology? Learn more about the format and content of the AP test, and get a rundown of the best resources you can use to study for the exam!

You should also read our complete review guide for AP Biology. You can use it to brush up on some skills that will come in handy for the Biology Subject Test as well.

While you're studying for the Biology Subject Test (or even if you're just taking bio), take advantage of our articles reviewing key bio concepts. Start with our exploration of the distinction between homologous and analogous structures, then go on to our guides to enzymes, the photosynthesis equation, cell theory, cell membranes, and the endoplasmic reticulum.

Still not sure whether you should take the Biology Subject Test? Check out this expert advice on which Subject Tests you should take based on your goals and interests.



These recommendations are based solely on our knowledge and experience. If you purchase an item through one of our links, PrepScholar may receive a commission.


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About the Author
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Samantha Lindsay

Samantha is a blog content writer for PrepScholar. Her goal is to help students adopt a less stressful view of standardized testing and other academic challenges through her articles. Samantha is also passionate about art and graduated with honors from Dartmouth College as a Studio Art major in 2014. In high school, she earned a 2400 on the SAT, 5's on all seven of her AP tests, and was named a National Merit Scholar.

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