BIOLOGY-YBI11 · Pearson Edexcel International A Level
BIOLOGY-YBI11/21
Paper 2
Biology · Winter 2025 · Variant 1
Relative difficulty
Analysis source: Pearson Edexcel
Analysis aligned to the official syllabus and assessment design.
3.7 / 5
440
550 min
Practical Design, Biodiversity and Statistical Analysis
Cohort performance
Session statistics from official examination reports
Total marks
440
Duration
550 min
Session difficulty
3.7 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
A significant proportion of marks was allocated to practical methodology and quantitative interpretation.
In Unit 3 and Unit 6, drawing plan diagrams (such as the mammalian heart's tendinous cords) and formulating complete experimental protocols (such as measuring blowfly larval respiration) carried substantial weight.
Candidates routinely lost marks for neglecting to state the precise dependent variable or omitting vital control measures.
Question difficulty map
How candidates performed on each question in this series
No data available in official reports
Assessment objectives
Skill and AO weighting from official examiner commentary
Skill weighting
Shows the skill mix this paper tested most heavily.
Knowledge & Understanding
Weight: 4100%Experimental
Weight: 375%Analysis & S
Weight: 250%Evaluation & Analysis
Weight: 125%
Method marks watchlist
Where working, steps, or method marks were commonly lost
No data available in official reports
Recurring mistakes across years
Themes examiners flag in multiple recent sessions for this subject
No data available in official reports
Question choice intelligence
Mean scores and popularity for optional questions (HKDSE electives)
No data available in official reports
Level exemplars
What candidate scripts at each grade level looked like
No data available in official reports
Grade & admission context
How marks relate to grade thresholds and entry standards
Report type
Examiner report — national grade boundaries and question-level commentary
Level A*
Approx. 90% of maximum mark
Level A
Approx. 80% of maximum mark
Level B
Approx. 70% of maximum mark
Level C
Approx. 60% of maximum mark
Level D
Approx. 50% of maximum mark
Level E
Approx. 40% of maximum mark
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
No data available in official reports
Command word playbook
How to match each command word to the expected response style
Give reasons and link mechanism to outcome; each point needs a because/so chain.
State features in sequence or list observable properties — do not explain causes unless asked.
Show formula, substitution, and unit; method marks need visible working.
Match the expected response style for “contrast” questions.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Match the expected response style for “State” questions.
Present multiple perspectives with evidence; balance breadth and depth.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 2
Min per mark: 1.6
Min per mark: 1.6
Min per mark: 1.2
Min per mark: 1.2
Min per mark: 1.1
Syllabus traceability
Topics linked to questions and mark weighting in this session
Plant Structure and Function, Biodiversity and Conservation
78 marks this session
Respiration, Muscles and the Internal Environment
64 marks this session
Coordination, Response and Gene Technology
62 marks this session
MCQ trap analytics
Commonly chosen wrong options from examiner commentary
No data available in official reports
Topic heatmap across years
Mark concentration by topic and exam year for this subject
Mark intensity
Plant Structure and Function, Biodiversity and Conservation
Coordination, Response and Gene Technology
Membranes, Proteins, DNA and Gene Expression
Respiration, Muscles and the Internal Environment
Microbiology, Immunity and Forensics
Molecules, Transport and Health
Energy Flow, Ecosystems and the Environment
Paper comparison
Marks and duration breakdown across papers in this session
WBI11/01: Unit 1 - Molecules, Diet, Transport and Health: WBI12/01: Unit 2 - Cells, Development, Biodiversity and Conservation: WBI13/01: Unit 3 - Practical Skills in Biology I: WBI14/01: Unit 4 - Energy, Environment, Microbiology and Immunity: WBI15/01: Unit 5 - Respiration, Internal Environment, Coordination and Gene Technology: WBI16/01: Unit 6 - Practical Skills in Biology II:
Marks you can still earn
Where valid approaches outside the mark scheme may still gain credit
No data available in official reports
Practise what examiners flagged
Target weak topics from this report inside the Revui app
Plant Structure and Function, Biodiversity and Conservation
78 marks this session
Practise in RevuiRespiration, Muscles and the Internal Environment
64 marks this session
Practise in RevuiCoordination, Response and Gene Technology
62 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
A significant proportion of marks was allocated to practical methodology and quantitative interpretation.
- 2Message
In Unit 3 and Unit 6, drawing plan diagrams (such as the mammalian heart's tendinous cords) and formulating complete experimental protocols (such as measuring blowfly larval respiration) carried substantial weight.
- 3Message
Candidates routinely lost marks for neglecting to state the precise dependent variable or omitting vital control measures.
Teacher briefing pack
One-page session summary for tutors and classroom review
Winter 2025 2025
Biology
A significant proportion of marks was allocated to practical methodology and quantitative interpretation. In Unit 3 and Unit 6, drawing plan diagrams (such as the mammalian heart's tendinous cords) and formulating complete experimental protocols (such as measuring blowfly larval
A significant proportion of marks was allocated to practical methodology and quantitative interpretation.
In Unit 3 and Unit 6, drawing plan diagrams (such as the mammalian heart's tendinous cords) and formulating complete experimental protocols (such as measuring blowfly larval respiration) carried substantial weight.
Candidates routinely lost marks for neglecting to state the precise dependent variable or omitting vital control measures.
- Total marks
- 440
- Duration
- 550 min
- Session difficulty
- 3.7 / 5
Session analysis
A significant proportion of marks was allocated to practical methodology and quantitative interpretation. In Unit 3 and Unit 6, drawing plan diagrams (such as the mammalian heart's tendinous cords) and formulating complete experimental protocols (such as measuring blowfly larval respiration) carried substantial weight. Candidates routinely lost marks for neglecting to state the precise dependent variable or omitting vital control measures.
Updated Jun 12, 2026
Paper breakdown
WBI11/01: Unit 1 - Molecules, Diet, Transport and Health: WBI12/01: Unit 2 - Cells, Development, Biodiversity and Conservation: WBI13/01: Unit 3 - Practical Skills in Biology I: WBI14/01: Unit 4 - Energy, Environment, Microbiology and Immunity: WBI15/01: Unit 5 - Respiration, Internal Environment, Coordination and Gene Technology: WBI16/01: Unit 6 - Practical Skills in Biology II:
Top chapters
Exam structure insights
Marks by chapter
See where the marks were concentrated so revision time goes to the highest-value topics.
Mark accessibility
Estimate which marks were basic, mid-level, or high-difficulty.
74% within easy or medium reach
Command word frequency
Spot common command words so answers match the expected response style.
Question type mix
Compare the mark share of each paper section and question type.
Short Answer
(explain/describe)
194·52·44%
Data Analysis & Evaluation
85·18·19%
Practical Planning & Methodology
72·12·16%
Calculations & Mathematical Skills
41·15·9%
Biological Drawings
30·5·7%
Multiple Choice Questions
18·18·4%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Difficulty trend
Compare difficulty across recent years.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Unit 1: Molecules,
0.50 m/minUnit 2: Cells, Deve
0.89 m/minUnit 3: Practical S
0.63 m/minUnit 4: Energy, Env
0.86 m/minUnit 5: Respiration
0.86 m/minUnit 6: Practical S
0.63 m/minTotal marks
380
Total time
500 min
Avg pace
0.76
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Electrocardiogram (ECG) Analysis and Cardiac Cycle
85%85%
Succession and Colonization Stages
80%80%
Synaptic Transmission & Muscle Contraction
78%78%
Examiner notes & key calculations
- Vague Definitions: Defining key terms like homeostasis or antibiotic without using precise scientific terms (e.g., failing to specify "dynamic equilibrium" or "killing/inhibiting the growth of bacteria").
- Mathematical Oversights: Failing to express final calculated values in standard form or to the requested number of significant figures (such as the UK population size estimate or magnification calculations).
- Splicing Concepts: Confusion over the role of spliceosomes, where many candidates incorrectly stated that *exons* are removed rather than *introns*.
- Comparative Command Words: In "Compare and contrast" questions, failing to explicitly write out both a similarity and a difference, or simply copying numbers from graphs without offering an analytical comparison.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.