BIOLOGY · HKDSE
BIOLOGY/21
(Elective Part - any 2 of 4 electives)
Biology · 2024 · Variant 1
Relative difficulty
Analysis source: Hong Kong Examinations and Assessment Authority (HKEAA)
Analysis aligned to the official syllabus and assessment design.
3.8 / 5
160
210 min
Animal physiology, enzymology and experimental analysis
Cohort performance
Session statistics from official examination reports
Total marks
160
Duration
210 min
Session difficulty
3.8 / 5
Level 5**
~76% of max
Level 5*
~69% of max
Level 5
~61% of max
Key examiner messages
Top priorities from the principal examiner before you revise
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate M
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars).
While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills.
Section A contains several low-correct-rate MC questions (e.g., Q23 on tactile discrimination at 15%, Q31 on auxin anomalies at 19%), demonstrating that rote learning is no longer sufficient to secure top grades.
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.
Analysis & G
Weight: 6100%Recall & Understanding
Weight: 583%Biological Experimental
Weight: 467%Logical
Weight: 233%Deduction & Logical
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
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.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Match the expected response style for “Deduce” questions.
Show formula, substitution, and unit; method marks need visible working.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.5
Min per mark: 1.5
Min per mark: 1.4
Min per mark: 1.3
Syllabus traceability
Topics linked to questions and mark weighting in this session
Essential life processes in animals
22 marks this session
Cellular energetics
16 marks this session
Human impact on the environment
11 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
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1 (Section A & B):
Paper 2 (Electives):
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 animals
22 marks this session
Practise in RevuiCellular energetics
16 marks this session
Practise in RevuiHuman impact on the environment
11 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate M
- 2Message
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars).
- 3Message
While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills.
- 4Message
Section A contains several low-correct-rate MC questions (e.g., Q23 on tactile discrimination at 15%, Q31 on auxin anomalies at 19%), demonstrating that rote learning is no longer sufficient to secure top grades.
Teacher briefing pack
One-page session summary for tutors and classroom review
2024 2024
Biology
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate M
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate M
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars).
While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills.
- Total marks
- 160
- Duration
- 210 min
- Session difficulty
- 3.8 / 5
- Level 5**
- ~76% of max
- Level 5*
- ~69% of max
- Level 5
- ~61% of max
Session analysis
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate MC questions (e.g., Q23 on tactile discrimination at 15%, Q31 on auxin anomalies at 19%), demonstrating that rote learning is no longer sufficient to secure top grades.
Updated Jun 11, 2026
Paper breakdown
Paper 1 (Section A & B):
Paper 2 (Electives):
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.
75% 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 Conventional
73·10·46%
Elective Structured Questions
40·4·25%
Multiple Choice
36·36·23%
Essay / Extended Writing
11·1·7%
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 (
0.80 m/minPaper 1 Section B (
0.73 m/minPaper 2 Elective 1
0.67 m/minPaper 2 Elective 4
0.67 m/minTotal marks
87
Total time
120 min
Avg pace
0.72
Cumulative marks ladder
The line is your running mark total question by question; dashed lines are the estimated grade cut-offs. See which question the line crosses your target grade at, so you know how far you must answer cleanly and which questions decide a band.
Difficulty Verdict
The 2024 HKDSE Biology exam presents a moderate-to-high difficulty level (3.8 out of 5 stars). While standard recall questions are present, candidates are heavily tested on their data-deduction abilities and scientific inquiry skills. Section A contains several low-correct-rate MC questions (e.g., Q23 on tactile discrimination at 15%, Q31 on auxin anomalies at 19%), demonstrating that rote learning is no longer sufficient to secure top grades.
Where the Marks Are
Marks are heavily concentrated in Essential Life Processes in Animals and Cellular Energetics. The conventional paper rewards precise terminology and structured logic. For instance, in Q4 (Capillary Exchange), candidates must explicitly link hydrostatic pressure gradient and water potential gradient to the direction of fluid movement. In Paper 2, candidates who chose Elective 1 (Human Physiology) and Elective 4 (Biotechnology) faced demanding experimental design tasks, including hormone feedback mechanism explanations and gel electrophoresis well placement logic.
Examiner notes & key calculations
- PCR Primer Selection (Paper 2 Q4b): Many candidates struggled to select the correct primers, failing to realize that primer Q, being too close to the restriction site, would result in truncated fragments that are lost during gel electrophoresis.
- Anode vs. Cathode Direction (Paper 2 Q4b): A classic blunder occurred where candidates failed to position sample wells near the cathode (negative pole), forgetting that DNA fragments are negatively charged and migrate towards the positive anode.
- Inadequate Controls in Experimental Design (Paper 1 Q7b): When designing a respiration set-up for algae, candidates often forgot to block out light (using aluminium foil) to prevent photosynthesis, which would otherwise recycle carbon dioxide and invalidate the respiration indicator.
Exam tips
Paper format
- Duration
- 1h
- Total marks
- 40
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.