AP Biology practice test: free questions, exam format and 2027 date

Each daily paper has 8 original free-response questions worth 25 to 35 marks. Between them, the two papers above cover most of the AP course. The AP Biology paper covers cellular energetics, gene expression and biotechnology, heredity, evolution and ecology. The Honors Biology paper covers biomolecules, enzymes, cells, membranes and the cell cycle. A few topics, such as the kidney and muscle contraction, go further into human physiology than AP Biology asks.

Where to find a real AP Biology practice test

• Past free-response questions: College Board posts recent AP Biology free-response questions on AP Central, with scoring guidelines and sample student answers. Find them from the Exam Preparation section of the course's exam page.
• AP Classroom: your teacher can unlock progress checks with multiple-choice and free-response questions, and assign practice or released exam questions from the AP Question Bank.
• Bluebook test preview: download the Bluebook app to see how the digital exam works. College Board says previews for most AP subjects are available now, with more coming in early 2027.
• A short daily practice test: the papers above, for 35 to 45 minutes of timed free-response practice.

AP Biology exam format for 2027

It is a hybrid digital exam: you answer the multiple-choice questions and read the free-response questions in the Bluebook app, then handwrite your free-response answers in a paper booklet. That gives you about 1.5 minutes per multiple-choice question and an average of 15 minutes per free-response question, though the two long ones need more. College Board provides reference materials, such as equation sheets and reference tables.

The free-response questions test whether you can interpret and evaluate results from an experiment, graph and analyze data, understand lab procedures, predict the effects of a change in a biological system, and analyze a visual representation such as a model or diagram.

AP Biology units and how much each is worth

Natural selection is the biggest single unit, at up to 20%. College Board recommends high school biology and chemistry before you start. The tools: the Cell Biology course, Genetics and DNA course, Cell Simulator, Genetics Cross Calculator, DNA Translator, Hardy-Weinberg Calculator, Natural Selection simulator, Population Growth Calculator and Ecology Calculator.

AP Biology practice test questions with answers

We wrote these for this page. Most AP Biology math comes down to a few calculations, so each question below practices one of them. Try each before reading the working.

1. Cells: surface area to volume

Question: Model two cells as cubes with sides of 1 μm and 3 μm. Which has the larger surface area to volume ratio, and why does it matter?

The small cube has surface area 6 μm² and volume 1 μm³, a ratio of 6 to 1. The large cube has 54 μm² and 27 μm³, a ratio of 2 to 1. The smaller cell has three times as much membrane per unit of volume, so it can exchange materials with its surroundings faster for its size. That is why cells stay small, or fold their membranes, as root hair cells and the small intestine do.

Try one yourself from our Cell Biology course. Answer it here and press Mark.

2. Cellular energetics: water potential

Question: A 0.20 M sucrose solution stands in an open beaker at 22 °C. Find its water potential. A plant cell with a water potential of −3.0 bars is placed in it. Which way does water move?

Sucrose doesn't ionize, so i = 1. Convert to kelvin: 22 + 273 = 295 K. R is 0.0831 liter bars per mole kelvin.

The beaker is open, so the pressure potential is 0 and the solution's water potential is −4.9 bars. Water moves from higher to lower water potential, so it leaves the cell (−3.0 bars) for the solution (−4.9 bars), and the cell loses turgor. The sign matters: −3.0 is the higher value.

3. Heredity: chi-square

Question: A dihybrid cross gives 160 offspring in four phenotype classes: 98, 26, 28 and 8. Do the results support the expected 9 : 3 : 3 : 1 ratio at p = 0.05?

The null hypothesis is that the ratio is 9 : 3 : 3 : 1. Split 160 in that ratio to get expected counts of 90, 30, 30 and 10, then add up (O − E)² ÷ E for each class.

There are 4 classes, so 3 degrees of freedom, and the critical value at p = 0.05 is 7.81. Since 1.78 is less than 7.81, you fail to reject the null hypothesis: the difference is small enough to be chance, and the data are consistent with 9 : 3 : 3 : 1. Say "fail to reject", not "prove". Check crosses with the Genetics Cross Calculator.

4. Natural selection: Hardy-Weinberg

Question: A recessive condition affects 1 in 400 people in a population in Hardy-Weinberg equilibrium. What fraction of the population are carriers?

Affected people are homozygous recessive, so q² = 1/400 = 0.0025. That gives q = 0.05 and p = 1 − 0.05 = 0.95. Carriers are heterozygous:

About 9.5%, or roughly 1 person in 10, carries the allele, even though only 1 in 400 shows the condition. The classic mistake is to take q = 0.0025 without the square root. The Hardy-Weinberg Calculator checks these.

5. Ecology: energy through a food chain

Question: Producers in a meadow capture 20,000 kcal per square meter per year. Assuming about 10% passes to each next level, how much reaches the tertiary consumers, and where does the rest go?

Three steps up: 20,000 → 2,000 → 200 → 20 kcal per square meter per year. The rest is used in cellular respiration and lost as heat, or stays in material that isn't eaten or digested, which decomposers use. This is why food chains rarely have more than four or five levels.

AP Biology scores and the 2026 score distribution

In 2026, 71% of AP Biology students scored 3 or higher, and a 3 was the most common score. Each college sets its own policy for which scores earn credit or placement.

AP Biology exam date 2027 and deadlines

• Exam: Monday, May 3, 2027, in the afternoon session. In the lower 48 states, Hawaii and Washington, D.C., that starts at 12 p.m. local time.
• Ordering deadline: November 13, 2026. Your school's AP coordinator orders your exam, and your school may set an earlier date.
• Fee: $99 per exam in the US, US territories and Canada, and $129 elsewhere, for 2026-27, plus $40 for exams ordered from November 14 to March 12. College Board takes $37 off for students with significant financial need.
• Scores: released in July 2027.

Use the daily paper as a short timed practice test

1. Open today's AP Biology paper with a scientific calculator, not a graphing one, to match the 2027 rules.
2. Work to the suggested time, 35 to 45 minutes. That is about the time of two long AP free-response questions.
3. Answer in full sentences that link a cause to its effect. AP free-response questions reward explanations, not lists of keywords.
4. Mark your work against the mark scheme and note the AP unit behind each lost mark. Alternate with the Honors Biology paper to cover Units 1 and 2.

Common AP Biology mistakes

• Describing instead of explaining: "the rate went up" describes; "the rate went up because more enzyme and substrate collided" explains.
• Getting water potential signs backward: water moves toward the more negative value.
• Forgetting the square root in Hardy-Weinberg: the recessive phenotype frequency is q², not q.
• Saying a chi-square test proves a hypothesis: you either reject the null hypothesis or fail to reject it.
• Changing more than one variable in an experimental design: name one independent variable and the variables you keep constant.
• Misreading graph axes: check the units and scale before you quote any value.

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