How to Structure Paper 5 Planning Questions in Cambridge A-Level Biology (9700)
Last Updated: October 2026 | By EdFlik Education Team
For high school students completing the Cambridge International AS & A Level Biology (9700) qualification, Paper 5 (Planning, Analysis and Evaluation) represents one of the most technical and challenging papers in the entire A-Level series. Worth 30 marks and lasting 1 hour and 15 minutes, Paper 5 evaluates high-level practical skills rather than basic factual recall.
The single largest section on Paper 5 is the Planning Question (Question 1), which typically carries 12 to 15 marks. In this task, candidates are presented with a novel biological context or hypothesis and asked to design a complete, scientifically sound laboratory investigation from scratch.
Every exam session, capable biology students lose crucial marks not because they lack theoretical knowledge, but because their experimental designs omit essential details: failing to state exact control variable values, leaving out risk assessments, omitting standard curve preparation steps, or forgetting how to calculate rates of reaction.
In this comprehensive, exam-focused masterclass guide, our expert Cambridge A-Level biology educators break down the Paper 5 planning rubric, introduce our foolproof 7-Step Experimental Design Framework, expose common examiner traps, and provide a 100% copy-paste JSON-LD schema markup for your study resources.
Part 1: Deconstructing the Paper 5 Planning Rubric
To score full marks on Question 1, your experimental proposal must address all aspects of the scientific method as specified by Cambridge CAIE examiners:
PAPER 5 PLANNING ASSESSMENT DOMAINS
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1. VARIABLES & HYPOTHESIS 2. EXPERIMENTAL METHODOLOGY
• Identify IV, DV, and controlled variables • Step-by-step reproducible protocol
with exact units and measurement tools. • Serial dilution preparation & controls
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3. SAFETY & RISK ASSESSMENT 4. DATA ANALYSIS & EVALUATION
• Hazard identification, risk level, and • Raw data tables, processing formulas,
specific mitigation measures. and statistical test selection.
Part 2: The 7-Step Paper 5 Experimental Design Framework
When presented with a planning question on Paper 5, organize your written response using this structured 7-step blueprint:
THE 7-STEP EXPERIMENTAL DESIGN BLUEPRINT
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Step 1: Variables & Hypothesis ---> Explicitly state IV, DV, and 3 Controlled Variables
Step 2: Dilution Strategy ---> Detail Simple or Serial Dilution protocol (5 concentrations)
Step 3: Control Experiment ---> Describe a negative control to prove IV causes DV
Step 4: Experimental Protocol ---> Write a chronological, numbered step-by-step procedure
Step 5: Safety & Risk ---> Identify Hazard, Specific Risk, and Precise Precaution
Step 6: Data Collection ---> Sketch a raw data table with units and detail replicates (n ≥ 3)
Step 7: Data Processing ---> Detail rate calculations, graphs, and statistical tests
Step 1: Define Variables Clearly (Including Exact Units and Tools)
- Independent Variable (IV): The variable you change. State at least 5 distinct concentrations or values across a suitable range (e.g., $0.2, 0.4, 0.6, 0.8, 1.0 \text{ mol dm}^{-3}$).
- Dependent Variable (DV): The variable you measure. Specify the exact equipment used to measure it (e.g., volume of $O_2$ gas measured using a $10 \text{ cm}^3$ gas syringe every $30\text{ seconds}$ for $5\text{ minutes}$).
- Controlled Variables: Name at least 3 variables that must be kept constant, stating the exact value, tool, and method used to control each (e.g., Temperature controlled at $37^\circ\text{C}$ using a thermostatically controlled water bath; pH controlled at pH $7.0$ using $5 \text{ cm}^3$ of phosphate buffer solution).
Step 2: Master Dilution Calculations (Simple vs. Serial)
Examiners frequently require you to explain how to prepare a range of concentrations from a given stock solution.
SIMPLE vs. SERIAL DILUTIONS
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SIMPLE DILUTION SERIAL DILUTION
• Mixing varying volumes of stock • Stepwise geometric dilution where
solution and distilled water. each concentration is diluted by a
• Uses $C_1 V_1 = C_2 V_2$ formula. constant factor (e.g., 10-fold or 2-fold).
Simple Dilution Example (Preparing $10\text{ cm}^3$ volumes of $0.2, 0.4, 0.6, 0.8\text{ mol dm}^{-3}$ from a $1.0\text{ mol dm}^{-3}$ stock):
- To prepare $0.2\text{ mol dm}^{-3}$: Mix $2.0\text{ cm}^3$ of $1.0\text{ mol dm}^{-3}$ stock solution with $8.0\text{ cm}^3$ of distilled water using a graduated $10\text{ cm}^3$ syringe.
Serial Dilution Example ($10$-fold dilution series):
- Transfer $1.0\text{ cm}^3$ of $1.0\text{ mol dm}^{-3}$ stock solution into $9.0\text{ cm}^3$ of distilled water in Test Tube 1 to produce $0.1\text{ mol dm}^{-3}$.
- Mix thoroughly, then transfer $1.0\text{ cm}^3$ from Test Tube 1 into $9.0\text{ cm}^3$ of distilled water in Test Tube 2 to produce $0.01\text{ mol dm}^{-3}$, repeating for 5 concentrations.
Step 3: Set Up a Negative Control
A negative control proves that the observed change in the dependent variable is caused solely by the independent variable and not by environmental factors.
- Example: Replace the active enzyme solution with an equal volume ($5\text{ cm}^3$) of boiled and cooled enzyme or distilled water, keeping all other environmental factors identical.
Step 4: Write a Chronological, Step-by-Step Procedure
Write your method in clear, numbered steps using imperative verbs. Ensure every volume, time, and apparatus is explicitly specified:
- Equilibrate the substrate and enzyme solutions separately in a $37^\circ\text{C}$ water bath for $10\text{ minutes}$ before mixing.
- Combine $5\text{ cm}^3$ of $1.0\text{ mol dm}^{-3}$ substrate with $5\text{ cm}^3$ of $5\%$ enzyme solution in a test tube.
- Immediately attach a rubber bung connected to a delivery tube and gas syringe.
- Start a stopwatch and record the volume of gas evolved every $30\text{ seconds}$ for a total of $5\text{ minutes}$.
Step 5: Construct a Rigorous Risk Assessment Table
Examiners demand a 3-part risk assessment: Hazard, Specific Risk, and Precaution.
| Hazard | Specific Risk / Nature of Hazard | Precise Precaution |
| Boiling Water / Hot Water Bath | Scalding or burns to skin upon contact | Wear heat-resistant gloves and handle test tube racks with tongs |
| Hydrochloric Acid ($1.0\text{ mol dm}^{-3}$) | Corrosive to eyes and skin irritant | Wear splash-proof safety goggles and nitrile gloves |
| Biological Enzymes (e.g., Pepsin powder) | Allergen / Respiratory irritant if inhaled | Wear a protective dust mask when weighing powder and handle solutions carefully |
Step 6: Plan Data Collection and Replicates
- Replicates: State that the entire procedure will be repeated at least 3 times (triplicates) for each concentration.
- Averages: Calculate the mean values for each concentration while explicitly identifying and excluding anomalous results prior to mean calculations.
- Raw Data Table Sketch: Draw a formatted data table with column headers containing variable names and slash units (e.g., $\text{Concentration / mol dm}^{-3}$, $\text{Time / s}$, $\text{Volume / cm}^3$).
Step 7: Outline Data Processing and Statistical Testing
- Rate Calculation: Explain how the rate of reaction will be calculated:$$\text{Rate of Reaction} = \frac{\text{Volume of Product Formed } (\text{cm}^3)}{\text{Time Taken } (\text{s})}$$Or explain how to draw a tangent at $t = 0\text{ s}$ on a concentration-time graph to determine the initial rate of reaction.
- Statistical Tests: Name an appropriate statistical test based on your data type:
- Student’s t-test: To compare the means of two independent groups.
- Pearson’s Linear Correlation ($r$) or Spearman’s Rank Correlation ($r_s$): To test for a relationship between two continuous variables.
- Chi-squared ($\chi^2$) test: To test for differences between observed and expected categorical frequencies.
Part 3: Top 4 Traps That Cost Students Marks in Paper 5
- Vague Controlled Variable Descriptions: Writing "keep temperature and pH the same" without specifying the tool or value. Always state: "Maintain temperature at $30^\circ\text{C}$ using a thermostatically controlled water bath."
- Confusing Simple and Serial Dilutions: Attempting to describe a serial dilution protocol using simple dilution calculations, resulting in incorrect concentration values.
- Generic Safety Statements: Writing "wear safety goggles and tie back hair." You must identify a specific chemical or biological hazard mentioned in the prompt (e.g., "sodium hydroxide is corrosive").
- Omitting Measurement Equipment: Writing "measure the gas given off" without naming the apparatus (e.g., "using a $50\text{ cm}^3$ gas syringe accurate to $\pm 0.5\text{ cm}^3$ ").
Preparing for Cambridge A-Level Biology (9700) Paper 5 exams and aiming for an $A^$ grade? EdFlik connects international school students globally with expert, 1-to-1 online A-Level biology tutors, helping you master practical experimental design, statistical evaluations, data processing, and past-paper mark scheme techniques. *Book a Free Demo Class Today!
Frequently Asked Questions (FAQs)
Q1: How many marks is Question 1 (Planning) worth on Paper 5?
Ans: Question 1 on Cambridge A-Level Biology (9700) Paper 5 typically carries between 12 and 15 marks out of the total 30 marks available on the paper.
Q2: What is the difference between Pearson's linear correlation and Spearman's rank correlation?
Ans: Pearson’s linear correlation ($r$) is used when data is normally distributed and shows a linear relationship between two continuous variables. Spearman’s rank correlation ($r_s$) is used when data is non-linear, not normally distributed, or ordinal/ranked.
Q3: How many concentrations should I include in my experimental plan?
Ans: You should always propose a minimum of 5 different concentrations or values for your independent variable to allow for a reliable trend line or standard curve to be plotted.
Q4: How does EdFlik support Cambridge A-Level Biology students?
Ans: EdFlik connects international school students worldwide with vetted, expert 1-to-1 online tutors specializing in Cambridge International AS & A Level Biology (9700). Our personalized coaching focuses on Paper 5 experimental design, statistical analysis, Paper 4 theory consolidation, and exam techniques.
