The AP (Advanced Placement) Biology free-response section is 6 questions in 90 minutes and worth 50% of your total score. It's where the biggest score swings happen, because unlike MCQs (multiple-choice questions), FRQs (free-response questions) are marked point-by-point against a rubric. Miss the specific wording or skip a required task word and you lose the point, even if your biology is right.
This guide covers what the 6 questions look like, how the rubrics are structured, and what to do in the first 90 seconds of each question to set yourself up for full marks. If you want structured content to back this up, Cognito's AP Biology course walks through each unit with quiz questions built to the same rubric style.
The 6 questions: What you actually face
Section II has 6 FRQs total: 2 long-response and 4 short-response. The long questions are typically worth 8-10 points each, the short questions are typically worth 4 points each. You get 90 minutes for the whole section, so pacing matters, spend too long on question 1 and questions 5 and 6 will be rushed.
College Board doesn't officially label the questions, but the topic patterns across recent years are consistent: One long question on experimental design or data interpretation, one long question focused on a system-level process (usually from Units 3, 4, 6 or 7), and four short questions covering scientific investigation, conceptual analysis, model interpretation and data analysis.
| Question | Typical points | What it looks like |
|---|---|---|
| Long 1 | 8-10 | Experimental scenario with data table or graph; interpret, predict, propose next experiment |
| Long 2 | 8-10 | System-level process (signaling pathway, metabolic pathway, evolutionary scenario); explain and predict |
| Short 1 | 4 | Scientific investigation - propose or evaluate a method |
| Short 2 | 4 | Conceptual analysis - explain a mechanism |
| Short 3 | 4 | Model interpretation - read a diagram or pathway |
| Short 4 | 4 | Data analysis - calculate or interpret from a data set |
How the rubrics actually work
Every FRQ point comes from a specific task word matched to a specific piece of biology. If the question says "identify one factor that would cause the rate of reaction to decrease", the point is awarded only for a plausible factor. If it says "explain how this factor would cause the rate to decrease", you need the factor AND the mechanism to get the point.
The rubric is written as a list of "accept" bullet points. Each bullet is one point. If you write a paragraph that hits three of the bullets, you get three points. If you write a beautiful paragraph that misses all three, you get zero. This is why loose paraphrasing kills scores, the graders are scanning for specific concepts, not evaluating your prose.
Rubric points are additive and independent. There's no penalty for extra wrong information as long as it isn't contradictory. If you're unsure, write more, not less - but ONE clear correct sentence per point.
Task verbs and what each one wants
The College Board uses a small set of task verbs across every FRQ. Learn what each one is asking for, a lot of lost marks come from students who explain when the question asks them to describe, or predict when it asks them to justify. For calculation questions specifically, our AP Biology formula sheet lists every equation with worked examples.
| Task verb | What it wants | Typical mark |
|---|---|---|
| Identify / State | A single word or short phrase | 1 point |
| Describe | What happens, in the right order, no reasoning | 1-2 points |
| Explain | What happens AND why (the mechanism) | 1-2 points |
| Predict | A specific outcome based on the scenario | 1 point |
| Justify | Your prediction PLUS the biological reasoning | 2 points |
| Calculate | A number with units and working shown | 1-2 points |
| Construct a graph | Axes labeled with units, correct scale, plotted points, best fit line if appropriate | 2-3 points |
| Design an experiment | Independent variable, dependent variable, controls, replicates, predicted results | 3-4 points |
The first 90 seconds of every FRQ
Before you write anything, do this three-step read:
Step 1: Read the whole question stem, including the scenario at the top and every sub-part. FRQs are built as connected scenarios, you can't answer part (c) properly without knowing what's in the stem and part (a).
Step 2: Underline every task verb and every specific biological term (organism names, reaction names, unit measurements). Circle any numbers you'll need to calculate with.
Step 3: Sketch a one-line answer plan next to each sub-part. Not full sentences, just the key concepts you'll write about. This takes about 30 seconds and stops you from missing sub-parts under time pressure.
Then start writing. This sequence adds 90 seconds but saves you the 5-10 minutes of thrashing that comes from misreading the question.
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Timing: 90 minutes across 6 questions
A sensible split is roughly 20-22 minutes for each long question and 10-12 minutes for each short. That leaves about 5 minutes at the end for checking, or reallocating to any question you didn't finish.
One pattern that helps: Do the short questions first if you're stronger on discrete recall, or do the long questions first if you're stronger on structured explanation. There's no fixed order, you can attack them in any sequence you like. What kills scores is starting with the hardest long question, spending 40 minutes on it, and then having 50 minutes for 5 remaining questions.
If you're running out of time on the last question, WRITE THE ANSWER PLAN INSTEAD OF PROSE. Rubric points can be picked up from bullet points that name the correct concept, even if you didn't have time to expand them into full sentences.
Sample prompts and how a top answer looks
Here's a short-response prompt in the style of released AP Biology FRQs:
"A researcher grows two populations of bacteria at 30 °C. Population A is exposed to antibiotic X; population B is a control. After 24 hours, population A has grown 3% while population B has grown 400%. (a) Identify the independent variable. (b) Predict what would happen to population A after 30 days of continued antibiotic exposure. (c) Justify your prediction using the concept of natural selection."
A full-marks answer looks like this:
(a) The independent variable is the presence or absence of antibiotic X. [1 point, identifies correctly]
(b) Population A will increase in size over 30 days as antibiotic-resistant bacteria come to dominate the population. [1 point, specific prediction]
(c) Bacteria vary in their genetic resistance to antibiotic X due to random mutation. Resistant bacteria survive and reproduce, while sensitive bacteria die, so the frequency of resistance alleles increases each generation. Over 30 days, the population is composed almost entirely of resistant bacteria, which then grow at close to the untreated rate. [2 points, one for variation and differential survival, one for allele frequency change over generations]
Notice how each sentence carries a rubric point. Nothing is decorative.
Common ways to lose points
Answering the wrong task verb costs points every year. If the question says "describe" and you explain why (adding reasoning that wasn't asked for) you don't lose points for the extra, but if you skip the description itself you can lose 1-2 points.
Being too vague also costs. Writing "the cell membrane is affected" gets zero when the rubric wants "the phospholipid bilayer becomes more fluid". Specific vocabulary, pumps, channels, receptors, gradients, is what the rubric scans for.
Skipping sub-parts is one of the biggest score-killers. Every sub-part is independently scored, so leaving (c) blank because you got stuck on (b) forfeits points you might have easily earned.
Failing to show your work on quantitative parts is a preventable loss. Even wrong final answers can pick up partial credit if the graders can see you set up the equation correctly. Always show setup, substitution and final answer with units.
Run through this list as soon as you turn to Section II. Ninety minutes disappears fast.
- Skim all 6 questions first to spot the easier ones
- Underline task verbs before writing any answer
- Answer every sub-part - even a one-sentence attempt can score
- Use precise biology vocab (organelle names, molecular names, process names)
- Show all working on quantitative parts
- Label graph axes with units AND make the scale even
- Leave 5 minutes at the end to check you've answered every sub-part
- If time is tight, bullet-point the final question rather than writing prose
How to practice FRQs before exam day
The AP Central website hosts free-response questions and scoring guidelines going back years. The single most useful drill is: Answer an FRQ, then score yourself against the official rubric. Do this with a highlighter, highlight every rubric point you hit, in whatever color, and count them. This calibrates your sense of what "good enough" looks like faster than any textbook can.
Aim for 15-20 FRQs across the year, split roughly by unit weighting. Two of them should be full 6-question papers under strict 90-minute timing, ideally in the last two weeks before the exam. If you want to pair this with structured content coverage, Cognito's AP Biology notes match the CED (Course and Exam Description) units and include practice questions built to the same rubric style. If you're doing multiple AP sciences at once, Cognito's AP hub has FRQ-style practice for Chemistry and Environmental Science too. Our AP Biology study guide shows how to fit FRQ practice into a three-month study plan.
