BIOLOGY · HKDSE
BIOLOGY/11
(Compulsory Part - Section A MC + Section B Conventional)
Biology · 2021 · Variant 1
Relative difficulty
Analysis source: Hong Kong Examinations and Assessment Authority (HKEAA)
Analysis aligned to the official syllabus and assessment design.
3.0 / 5
160
210 min
Plant Ecology and Physiology
Cohort performance
Session statistics from official examination reports
Total marks
160
Duration
210 min
Session difficulty
3.0 / 5
Level 5**
~78% of max
Level 5*
~71% of max
Level 5
~62% of max
Key examiner messages
Top priorities from the principal examiner before you revise
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B bl
The 2021 paper is rated 3 out of 5 stars.
It maintains a stable difficulty level comparable to recent years.
The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly).
Section B blends classic human physiology with challenging scientific inquiries, particularly regarding plant stress and experimental validation.
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.
Recall & Understanding
Weight: 6100%Definitions Interpretation
Weight: 583%Experimental
Weight: 350%Scientific Communication
Weight: 233%
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
Reporting source
HKEAA Subject Examination Report — comments on candidates’ performance with marking schemes
Level 5**
Outstanding — competitive JUPAS programmes (medicine, law, top faculties)
Level 5*
Excellent — strong JUPAS profile for selective programmes
Level 5
Good — meets most university entrance requirements
Level 4
Satisfactory — foundation programmes or less selective routes
Level 3
Pass threshold for many sub-degree and vocational pathways
Admission context
Levels feed JUPAS and non-JUPAS university applications; 5** and 5* are most selective
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.
Present multiple perspectives with evidence; balance breadth and depth.
Identify similarities and differences explicitly — paired sentences or a table helps.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 2.3
Min per mark: 1.5
Min per mark: 1.2
Min per mark: 0.3
Min per mark: 0.1
Syllabus traceability
Topics linked to questions and mark weighting in this session
Essential life processes in plants
20 marks this session
Human impact on the environment
20 marks this session
Essential life processes in animals
18 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
Essential life processes in animals
Essential life processes in plants
Biodiversity and evolution
Human impact on the environment
Ecosystems
Cellular energetics
Basic genetics
Molecular genetics
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1 (Section A & B):
Paper 2 (Electives A & B):
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
Essential life processes in plants
20 marks this session
Practise in RevuiHuman impact on the environment
20 marks this session
Practise in RevuiEssential life processes in animals
18 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B bl
- 2Message
The 2021 paper is rated 3 out of 5 stars.
- 3Message
It maintains a stable difficulty level comparable to recent years.
- 4Message
The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly).
- 5Message
Section B blends classic human physiology with challenging scientific inquiries, particularly regarding plant stress and experimental validation.
Teacher briefing pack
One-page session summary for tutors and classroom review
2021 2021
Biology
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B bl
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B bl
The 2021 paper is rated 3 out of 5 stars.
It maintains a stable difficulty level comparable to recent years.
- Total marks
- 160
- Duration
- 210 min
- Session difficulty
- 3.0 / 5
- Level 5**
- ~78% of max
- Level 5*
- ~71% of max
- Level 5
- ~62% of max
Session analysis
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B blends classic human physiology with challenging scientific inquiries, particularly regarding plant stress and experimental validation.
Updated Jun 11, 2026
Paper breakdown
Paper 1 (Section A & B):
Paper 2 (Electives A & B):
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.
80% 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.
Paper 1B)
73·10·46%
Paper 2)
40·4·25%
Paper 1A)
36·36·23%
Paper 1B)
11·1·7%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 1A MC
0.83 m/minPaper 1B Q1-Q
9.89 m/minPaper 1B Q6-Q1
0.44 m/minPaper 1B Q11 (Essay)
0.67 m/minPaper 2 Elective
4.00 m/minTotal marks
724
Total time
175 min
Avg pace
4.14
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Techniques in modern biotechnology (PCR & Electrophoresis)
88%88%
Regulation of water content (Osmoregulation)
85%85%
Difficulty Verdict
The 2021 paper is rated 3 out of 5 stars. It maintains a stable difficulty level comparable to recent years. The multiple-choice section contains several high-distinction questions (e.g., Q28 on domain classification, where only 12% of candidates answered correctly). Section B blends classic human physiology with challenging scientific inquiries, particularly regarding plant stress and experimental validation.
Where the Marks Are
High-yield topics include Essential life processes in plants (20 marks) and Human impact on the environment (20 marks in Applied Ecology). In Paper 1B, substantial marks are allocated to explaining mechanisms (such as the impact of gallstones on fat digestion in Q1, and synaptic transmission in Q2) and interpreting experimental variables (such as the bee-induced flowering investigation in Q7).
Examiner notes & key calculations
- Vague Terminology: In Q1(b), many candidates failed to name specific components of the pancreatic/bile secretions (lipase, bile salts, and NaHCO3\text{NaHCO}_3NaHCO3) and map them directly to their digestive functions.
- Weak Graphing Skills: In Q8(c)(ii), drawing the net carbon dioxide uptake curve for lower-region leaves was a major stumbling block. Candidates failed to reflect the physiological realities of shade leaves, which have lower dark respiration rates (higher starting point at zero light) and lower light-saturation points.
- Incomplete Essay Structure: In Q11 (the essay on variation), many candidates listed sources of variation without explaining the actual cytological mechanisms (e.g., independent assortment and crossing over in meiosis) or demonstrating how variation enables natural selection.
Exam tips
Paper format
- Duration
- 2h 30min
- Total marks
- 120
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.