BIOLOGY-A-H420 · Cambridge OCR A Level
BIOLOGY-A-H420/21
Paper 2
Biology A - H420 · 2023 · Variant 1
Relative difficulty
Analysis source: OCR
Analysis aligned to the official syllabus and assessment design.
3.8 / 5
270
360 min
Experimental investigation, calculations, and data evaluation across transport, respiration, and ecosystem dynamics.
Cohort performance
Session statistics from official examination reports
Total marks
270
Duration
360 min
Session difficulty
3.8 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty.
While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding experimental methodology, statistical analysis, and synoptic evaluations—pushed this paper into the higher difficulty tier.
Paper 3 (Unified Biology) acted as a true synoptic test, requiring rapid shifting of context between cellular biochemistry and macroscopic ecology.
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.
Theoretical Recall
Weight: 6100%Scientific
Weight: 467%Inquir
Weight: 350%Mathematical & Calculation
Weight: 233%Interpretation
Weight: 117%
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. 68% of maximum mark
Level A
Approx. 57% of maximum mark
Level B
Approx. 48% of maximum mark
Level C
Approx. 39% of maximum mark
Level D
Approx. 30% of maximum mark
Level E
Approx. 22% 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.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Show formula, substitution, and unit; method marks need visible working.
Weigh arguments for and against with evidence; end with a supported judgement.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.4
Min per mark: 1.4
Min per mark: 1.3
Min per mark: 1.3
Min per mark: 1.3
Syllabus traceability
Topics linked to questions and mark weighting in this session
Respiration
19 marks this session
Transport in animals
18 marks this session
Populations and sustainability
16 marks this session
Cloning and biotechnology
16 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
Cloning and biotechnology
Biodiversity
Plant and animal responses
Manipulating genomes
Cell division, cell diversity and cellular organisation
Photosynthesis
Respiration
Transport in animals
Paper comparison
Marks and duration breakdown across papers in this session
H420/01 Biological processes: H420/02 Biological diversity: H420/03 Unified biology:
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
Respiration
19 marks this session
Practise in RevuiTransport in animals
18 marks this session
Practise in RevuiPopulations and sustainability
16 marks this session
Practise in RevuiCloning and biotechnology
16 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty.
- 2Message
While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding experimental methodology, statistical analysis, and synoptic evaluations—pushed this paper into the higher difficulty tier.
- 3Message
Paper 3 (Unified Biology) acted as a true synoptic test, requiring rapid shifting of context between cellular biochemistry and macroscopic ecology.
Teacher briefing pack
One-page session summary for tutors and classroom review
2023 2023
Biology A - H420
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty. While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding expe
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty.
While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding experimental methodology, statistical analysis, and synoptic evaluations—pushed this paper into the higher difficulty tier.
Paper 3 (Unified Biology) acted as a true synoptic test, requiring rapid shifting of context between cellular biochemistry and macroscopic ecology.
- Total marks
- 270
- Duration
- 360 min
- Session difficulty
- 3.8 / 5
Session analysis
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty. While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding experimental methodology, statistical analysis, and synoptic evaluations—pushed this paper into the higher difficulty tier. Paper 3 (Unified Biology) acted as a true synoptic test, requiring rapid shifting of context between cellular biochemistry and macroscopic ecology.
Updated Jun 14, 2026
Paper breakdown
H420/01 Biological processes: H420/02 Biological diversity: H420/03 Unified biology:
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.
70% 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.
Structured/Short Answer Questions
216·52·80%
Multiple Choice Questions
30·30·11%
Level of Response
(Longer Essay style)
24·4·9%
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.
Paper 1 Section A (
0.75 m/minPaper 1 Section B (
0.74 m/minPaper 2 Section A (
0.75 m/minPaper 2 Section B (
0.74 m/minPaper 3 (Unified)
0.78 m/minTotal marks
270
Total time
360 min
Avg pace
0.75
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Photosynthesis (Light Dependent & Independent Reactions, Calvin Cycle)
5%5%
Nucleotides and DNA replication
4%4%
Difficulty Verdict
The 2023 OCR A Level Biology A series sits at a solid 3.8 out of 5 in terms of difficulty. While Paper 1 and Paper 2 provided accessible entry points via straightforward Multiple Choice Questions (Section A), the level of detail demanded in Section B—particularly surrounding experimental methodology, statistical analysis, and synoptic evaluations—pushed this paper into the higher difficulty tier. Paper 3 (Unified Biology) acted as a true synoptic test, requiring rapid shifting of context between cellular biochemistry and macroscopic ecology.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.