FRQs 1-2 – Long Essay Questions

Overview

The AP Bio long free-response questions (FRQs 1 and 2) are the two highest-value writing tasks on the exam, worth 9 points each. You get them as part of Section II, which gives you 90 minutes for all 6 free-response questions and counts for 50% of your total score. Both long FRQs share the same name, "Interpreting and Evaluating Experimental Results," and both hand you a real research scenario with data. The key difference: FRQ 1 gives you graphs or tables to interpret, while FRQ 2 makes you build the graph yourself.

These aren't essay questions in the literature-class sense. You won't write five paragraphs about one big idea. Instead you'll work through four parts (A, B, C, D) that walk you through an experiment, asking you to describe biology, read or construct data, run calculations, and justify predictions with evidence. Think of them as "show me you can think like a researcher" questions. For the full Section II picture and the four short FRQs that round it out, see the AP Biology Exam guide.

How the AP Bio Long FRQs Are Scored

Each long FRQ is worth 9 points, split across four parts that are scored independently. You can miss a point in Part B and still earn every point in Parts C and D. The two questions have slightly different point splits because FRQ 2 includes a graphing task.

A few scoring facts that change how you should write:

• Answers must be in complete sentences. Outlines, bulleted lists, and diagrams alone will not be scored. You can use a graph or sketch as a supplement, but the actual answer has to be written out.
• Calculations earn points in pieces. You usually get one point for the correct setup or process and another for the correct answer with units. Show your work, because a calculator slip won't cost you the process point.
• Units are not optional. Rubrics specifically check for them. An unlabeled number is a wrong number.
• Graders look for specific key terms. "Describe the cause of an amino acid substitution" wants "a change in the DNA sequence," not just "mutation."

Heads up on content: the AP Bio course was updated for fall 2025 (first tested May 2026) with some resequencing in Units 1-3 and biogeochemical cycles added to ecology. The exam structure, timing, and the 9-point value of the long FRQs did not change.

How to Write the AP Bio LEQ, Step by Step

Budget roughly 22-25 minutes per long FRQ. Read first, write second. Most lost points come from rushing the scenario and confusing the variables.

Minutes 1-3: Read the whole scenario

The research setup at the top isn't decoration, it's the context for all four parts. Before writing anything, pin down four things: What question are the researchers investigating? What's the independent variable (what they changed)? What's the dependent variable (what they measured)? What's being held constant? Get these wrong and the errors cascade through every part.

Minutes 4-8: Knock out Parts A and B

Part A almost always asks you to describe a biological concept tied to the experiment. It's the warm-up, usually the easiest point, and you can often earn it from general knowledge even if the experiment confuses you.

Part B is where the two questions split. On FRQ 1 you'll identify experimental methods (the dependent variable, a control, a procedure) or describe a data pattern. On FRQ 2 you build the graph. Don't make the graph perfect, make it clear and accurate, then move on.

Minutes 9-15: Work through Part C

Part C is usually the time sink: calculations, statistical tests, or detailed analysis. Write your setup before you touch the calculator. For a mean, write "Mean growth rate = (final - initial) / time" so the grader sees you understand the process. If you're past 7-8 minutes here, make your best attempt and keep going. You can circle back.

Minutes 16-22: Finish Part D and check

Part D wants a prediction and a justification. The prediction has to be specific and consistent with the data, not "it will increase" but "the resistant population will increase because." The justification has to name the biological mechanism. If you understood the experiment, this part often writes itself. Save the last minute or two to confirm you answered every part, labeled units, and (for FRQ 2) finished the graph.

Graphing on FRQ 2

FRQ 2's Part B is worth 4 points, the single biggest chunk on either long question, so treat it like a mini-task with its own rules. A solid graph takes 3-4 minutes.

• Pick the right type. Bar graphs for discrete categories (different treatments, different species). Line graphs for continuous data (time, dose-response). Look at your x-axis variable: if it's continuous, go line.
• Label everything. Both axes need names and units. Independent variable on the x-axis, dependent on the y-axis. Add a title.
• Scale to fill the grid. Use most of the space. If values run 20-80, don't set the y-axis to 0-1000. Start at zero unless there's a real reason not to.
• Plot accurately and use a straight edge. Clear dots for line graphs, neat bars for bar graphs.
• Include error bars if the data has them. If the table gives ± values or standard error, you must draw error bars. Thin lines with small caps. Overlapping error bars suggest no significant difference between groups, which matters for your Part D reasoning.

Statistical Analysis That Earns Points

Part C frequently includes a statistical task. Know these three cold.

Chi-square. When you see observed versus expected ratios, reach for chi-square. State the null hypothesis (observed matches expected), calculate the chi-square value, find degrees of freedom (number of categories minus 1), and state whether you reject or fail to reject the null. Critical values are usually provided, so you don't need to memorize them. Skip any one of these steps and you lose the point.

Means and error. Mean = (sum of values) / (number of values). When you compare two means, look at the error. If standard error bars don't overlap, the difference is significant. If they overlap a lot, you can't claim a real difference, and that should shape what you say in Part D.

Rates and slopes. Rate = change / time. Watch the units: growth in mm over time in hours gives mm/hour. On a graph, slope is the rate of change, and a steeper slope means a faster rate.

Worked Example: A Strong Part D

Say FRQ 1 gives you data showing an insecticide-resistant insect population growing after spraying, and Part D asks you to predict and justify what happens if spraying continues.

Weak (vague, no mechanism): "The population will keep increasing because the insects are resistant."

Strong (specific prediction + biological reasoning): "The proportion of resistant individuals will continue to increase. Spraying acts as a selective pressure that kills susceptible insects, so resistant individuals survive and reproduce. Because resistance is heritable, a larger fraction of each generation carries the resistance allele, raising its frequency in the population over time."

The strong version names the mechanism (selection on a heritable trait, allele frequency change) instead of restating the claim. That's the difference between the prediction point alone and both Part D points.

Common Mistakes

• Rushing the scenario. Skipping the setup leads to swapped variables, which poisons every part. Spend the full 2-3 minutes reading before you write.
• Writing in bullets or fragments. Outlines and lists alone are not scored. Answer every part in complete sentences, even the short ones.
• Dropping units. A calculation without units doesn't earn the answer point. Write the units every time, even when they feel obvious.
• Stopping at the prediction. Part D needs the prediction and the biological justification. "It will decrease" with no mechanism gets you half the points at best.
• Graphing errors on FRQ 2. Putting the independent variable on the y-axis, forgetting units, cramming data into a corner, or skipping required error bars all cost points even when your plotting is accurate.
• Claiming a difference with overlapping error bars. If the variability overlaps, you can't say two groups differ. The exam is checking whether you understand significance, not just averages.

Practice and Next Steps

The fastest way to get comfortable with the long FRQs is to write full responses under a timer, then check them against real scoring. Work through the FRQ practice with instant scoring to see exactly where you're earning and losing points, and pull from the FRQ question bank and past exam questions for authentic research scenarios. When you want to test your pacing across the whole 90-minute section, take a full-length practice exam and run your raw score through the AP score calculator. For the four shorter free-response questions, see the FRQs 3-6 short answer guide.