--- title: "AP Biology Science Practice 6: Argumentation Study Guide" description: "Learn AP Biology Science Practice 6 (Argumentation): make claims, support them with evidence, give reasoning, link results to theory, and predict effects." canonical: "https://fiveable.me/ap-bio/science-practices/science-practice-6-argumentation/study-guide/isdwDbRObsIJSZuqu6nF" type: "study-guide" subject: "AP Biology" unit: "Science Practices" lastUpdated: "2026-06-17" --- # AP Biology Science Practice 6: Argumentation Study Guide ## Summary Learn AP Biology Science Practice 6 (Argumentation): make claims, support them with evidence, give reasoning, link results to theory, and predict effects. ## Guide ## Overview [AP Biology](/ap-bio "fv-autolink") Science Practice 6 (Argumentation) is the skill of building and defending scientific arguments using evidence. You make a claim, back it up with biological evidence and data, explain your reasoning by connecting that evidence to biological theories, and predict what happens when a system changes. In short, you are not just stating what is true. You are showing why it is true and how it fits the bigger picture of biology. This practice runs through every unit, from [enzyme function](/ap-bio/unit-3/enzyme-catalysis/study-guide/Jg1jljQ8ZHUvcaKprPGy "fv-autolink") in [Unit 3](/ap-bio/unit-3 "fv-autolink") to natural selection in Unit 7. It shows up on both the multiple-choice and free-response sections, so getting comfortable with argumentation pays off across the whole exam. ## What Science Practice 6 - Argumentation Means Argumentation in biology means using a clear structure to explain a scientific position. A strong argument usually has three parts: - A **claim**: a statement that answers a question or takes a position. - **Evidence**: biological principles, concepts, processes, or data that support the claim. - **Reasoning**: the link that explains why the evidence supports the claim, tied to established biological theories. Science Practice 6 also asks you to connect experimental results to larger ideas and to predict the effects of changes in a biological system. You are doing the work a scientist does after collecting data: deciding what it means and what it implies. ## What This Practice Requires The practice breaks into five subskills. Cover all of them: - **6.A: Make a scientific claim.** State a clear, defensible position based on an observation, data, or a model. - **6.B: Support a claim with evidence.** Use biological principles, concepts, processes, and data to back the claim. Evidence can come from the question, a figure, or your course knowledge. - **6.C: Provide reasoning to justify a claim.** Connect your evidence to biological theories so it is clear why the evidence matters. This is the step that explains the link, not just lists facts. - **6.D: Explain the relationship between experimental results and larger concepts.** Show how a specific result connects to broader biological processes, concepts, or theories. - **6.E: Predict causes or effects of a change or disruption.** Given a change to one or more components of a biological system, predict what will happen next and why. ## Skills You Need for This Practice To argue well in AP Biology, you need to: - Read data and figures carefully, then translate what you see into a position. - Pull the correct biological concept from memory and match it to the situation. - Separate a claim from its support. A claim alone is not an argument. - Use cause and effect language clearly, especially for predictions. - Connect a narrow result to a wider theory like [evolution](/ap-bio/unit-7/intro-natural-selection/study-guide/v9Lf9qQpmpSXvd2ZUOqH "fv-autolink"), [homeostasis](/ap-bio/key-terms/homeostasis "fv-autolink"), or energy flow. Argumentation builds on other practices. You often describe data (Practice 4) or do a calculation (Practice 5) first, then use that as evidence for a claim. ## How It Shows Up on the AP Exam All six [science practices](/ap-bio/science-practices "fv-autolink") appear on every AP Biology Exam, in both sections. **Multiple choice:** Questions ask you to pick the claim best supported by data, identify the most likely consequence of a disruption, or choose the best explanation linking a result to a concept. For example, a question about phytoplankton growth in a divided lake asks which claim the data best supports, and another asks for the direct consequence of adding [phosphate](/ap-bio/unit-1/nucleic-acids/study-guide/RKOM4rhL6iJsAMdbDOWU "fv-autolink") to the lake. **Free response:** The FRQ section has 6 questions. Argumentation is central to questions that ask you to make and justify claims, interpret experimental results, and predict outcomes. Questions like Interpreting and Evaluating Experimental Results and Analyze Data reward clear claim-evidence-reasoning structure. Practical tip: on FRQs, write a sentence that names your claim, a sentence with specific evidence, and a sentence of reasoning. Graders look for each part. ## Examples Across the Course Argumentation looks different depending on the content. Here are varied examples: - **Unit 3, [Enzymes](/ap-bio/unit-3/enzyme-structure/study-guide/jsjBfuk2jmYAZVrmVwtF "fv-autolink") (data and reasoning):** Given a graph of trypsin activity across pH values, claim that trypsin is denatured at extremely low pH. Your evidence is the sharp drop in activity at low pH, and your reasoning ties it to how pH disrupts the [protein structure](/ap-bio/key-terms/protein-structure "fv-autolink") needed for function. - **Unit 5, Heredity (prediction, 6.E):** Predict the consequence if chromosomes fail to separate during [meiosis II](/ap-bio/key-terms/meiosis-ii "fv-autolink"). The claim is that gamete [chromosome number](/ap-bio/key-terms/chromosome-number "fv-autolink") is altered, and reasoning connects nondisjunction to changes in chromosome number across generations. - **Unit 7, Natural Selection (prediction and theory):** Apple maggot flies that prefer apples versus hawthorn fruit mate near different fruits that ripen at different times. Claim that the population may split into two species, with reduced [gene flow](/ap-bio/key-terms/gene-flow "fv-autolink") as your evidence and [speciation](/ap-bio/unit-7/speciation/study-guide/EvkCBpDW4LggHrVIepHo "fv-autolink") theory as your reasoning. - **[Unit 8](/ap-bio/unit-8 "fv-autolink"), Ecology (claim from data, 6.B and 6.D):** In a divided-lake experiment, the side treated with sucrose and phosphate grew far more phytoplankton than the carbon-only side. Claim that phosphate was the limiting nutrient, then connect that result to the larger concept of [limiting factors](/ap-bio/key-terms/limiting-factors "fv-autolink") and energy flow through ecosystems. - **[Unit 2](/ap-bio/unit-2 "fv-autolink"), Cells (cause and effect, 6.E):** Red onion cells placed in a 15% NaCl solution shrink. Claim that water left the cells, with reasoning tied to osmosis and water moving toward higher [solute concentration](/ap-bio/unit-2/tonicity-osmoregulation/study-guide/i3qUckt9PGfT4pQlHq5B "fv-autolink"). ## How to Practice Science Practice 6 - Argumentation - Use a claim, evidence, reasoning template for every open response. Write each part as its own sentence so nothing gets skipped. - When you read a figure, force yourself to write one claim it supports before checking answer choices. - For prediction questions, ask "if this component changes, what happens to the next step, and why?" - Practice connecting small results to big ideas. After interpreting any data set, name the broader concept it illustrates, such as homeostasis, [common ancestry](/ap-bio/unit-7/common-ancestry/study-guide/FNiYICtpxNBjLu17IWjK "fv-autolink"), or energy flow. - Quiz yourself on the difference between evidence and reasoning. Evidence is the fact or data point. Reasoning is the explanation of why it supports the claim. - Rework multiple-choice answers you got wrong by writing the full argument behind the correct choice. ## Common Mistakes - **Stating a claim without support.** A claim by itself earns little. Always attach evidence and reasoning. - **Confusing evidence with reasoning.** Listing a data point is evidence. You still need a sentence explaining why it backs the claim. - **Restating the data instead of interpreting it.** Saying values went up is description. The argument needs what that increase means. - **Vague predictions.** "Things will change" is not enough. Name the specific effect and the cause behind it. - **Ignoring the larger concept.** For 6.D, connect your specific result to a broader process or theory, not just the experiment itself. - **Using evidence that does not match the claim.** Make sure the data or concept you cite actually supports the position you took. ## Quick Review - Science Practice 6 is about building and justifying scientific arguments with evidence. - **6.A** make a claim, **6.B** support it with evidence, **6.C** justify it with reasoning tied to theory, **6.D** connect results to larger concepts, **6.E** predict causes or effects of a disruption. - A complete argument has a claim, evidence, and reasoning. Skipping any part weakens it. - This practice appears on both exam sections and across all units, from cells to ecology. - On FRQs, write each part of the argument as a separate sentence so graders can find it. - For prediction questions, focus on clear cause and effect plus the biological reason behind it.