Biology question insights
What 11 years of ICSE Class 10 Biology papers actually asked — by chapter, question length, type, difficulty and diagrams. Every figure is computed from the 868 questions in this bank.
These are descriptive statistics of past papers, not predictions. A chapter appearing often historically does not guarantee it will appear again.
Which chapters carry the most weight
A prominence index combining how many papers a chapter appeared in and its share of total marks.
Chapter prominence index (0–100)
- The Endocrine System95/100Appeared in 91% of papers (10/11) · 9.7% of all marks (97) · 65 Qs
- The Circulatory System94/100Appeared in 91% of papers (10/11) · 9.6% of all marks (95.5) · 87 Qs
- Sense Organs94/100Appeared in 91% of papers (10/11) · 9.6% of all marks (95.5) · 87 Qs
- Structure of Chromosomes, Cell Cycle and Cell Division87/100Appeared in 91% of papers (10/11) · 7.8% of all marks (78) · 70 Qs
- Photosynthesis87/100Appeared in 91% of papers (10/11) · 7.8% of all marks (78) · 66 Qs
- The Nervous System87/100Appeared in 91% of papers (10/11) · 7.8% of all marks (78.5) · 64 Qs
- The Reproductive System85/100Appeared in 82% of papers (9/11) · 8.8% of all marks (88) · 82 Qs
- Pollution – A Rising Environmental Problem81/100Appeared in 82% of papers (9/11) · 7.8% of all marks (77.5) · 68 Qs
- Transpiration81/100Appeared in 91% of papers (10/11) · 6.5% of all marks (64.5) · 60 Qs
- Genetics – Some Basic Fundamentals80/100Appeared in 91% of papers (10/11) · 6.2% of all marks (62) · 62 Qs
- The Excretory System80/100Appeared in 91% of papers (10/11) · 6.2% of all marks (61.5) · 49 Qs
- Absorption by Roots – The Processes Involved72/100Appeared in 91% of papers (10/11) · 4.3% of all marks (43) · 37 Qs
Index = 60% appearance frequency + 40% marks share, across all available papers. Historical, not predictive.
The Endocrine System leads: it appears in 91% of papers (10 of 11) and carries 9.7% of all marks (97) across 65 questions.
Most questions asked
Share of all questions, by chapter.
- The Circulatory System10%87 Qs
- Sense Organs10%87 Qs
- The Reproductive System9.4%82 Qs
- Structure of Chromosomes, Cell Cycle and Cell Division8.1%70 Qs
- Pollution – A Rising Environmental Problem7.8%68 Qs
- Photosynthesis7.6%66 Qs
- The Endocrine System7.5%65 Qs
- The Nervous System7.4%64 Qs
- Genetics – Some Basic Fundamentals7.1%62 Qs
- Transpiration6.9%60 Qs
Percentages are of the full 868-question bank.
Most marks asked
Share of total marks, by chapter.
- The Endocrine System9.7%97 marks
- The Circulatory System9.6%95.5 marks
- Sense Organs9.6%95.5 marks
- The Reproductive System8.8%88 marks
- The Nervous System7.8%78.5 marks
- Structure of Chromosomes, Cell Cycle and Cell Division7.8%78 marks
- Photosynthesis7.8%78 marks
- Pollution – A Rising Environmental Problem7.8%77.5 marks
- Transpiration6.5%64.5 marks
- Genetics – Some Basic Fundamentals6.2%62 marks
Percentages are of the 1,000 marks across all papers.
Short vs long questions
Short = less than 2 marks (recall / one-liners). Long = 2 marks or more (explanations, diagrams, reasoning).
Overall split
- Short (<2 marks)772(89%)
- Long (≥2 marks)96(11%)
Short vs long by chapter
How each chapter's questions divide between short and long.
- Short (<2 marks)
- Long (≥2 marks)
- The Circulatory System90% short (78) · 10% long (9)
- Sense Organs91% short (79) · 9% long (8)
- The Reproductive System93% short (76) · 7% long (6)
- Structure of Chromosomes, Cell Cycle and Cell Division87% short (61) · 13% long (9)
- Pollution – A Rising Environmental Problem84% short (57) · 16% long (11)
- Photosynthesis94% short (62) · 6% long (4)
- The Endocrine System82% short (53) · 18% long (12)
- The Nervous System88% short (56) · 13% long (8)
- Genetics – Some Basic Fundamentals97% short (60) · 3% long (2)
- Transpiration92% short (55) · 8% long (5)
- The Excretory System84% short (41) · 16% long (8)
- Absorption by Roots – The Processes Involved84% short (31) · 16% long (6)
Most short-answer-heavy chapters
Best for quick recall and one-mark practice.
- Chemical Coordination in Plants100%28/2828 of 28 are short (under 2 marks)
- Genetics – Some Basic Fundamentals97%60/6260 of 62 are short (under 2 marks)
- Photosynthesis94%62/6662 of 66 are short (under 2 marks)
- The Reproductive System93%76/8276 of 82 are short (under 2 marks)
- Transpiration92%55/6055 of 60 are short (under 2 marks)
Most long-answer-heavy chapters
Where higher-mark, explanation-type questions cluster.
- Human Evolution21%4/194 of 19 are long (≥2 marks)
- Population – The Increasing Numbers and Rising Problems20%4/204 of 20 are long (≥2 marks)
- The Endocrine System18%12/6512 of 65 are long (≥2 marks)
- The Excretory System16%8/498 of 49 are long (≥2 marks)
- Absorption by Roots – The Processes Involved16%6/376 of 37 are long (≥2 marks)
How questions are framed
Question types
Share of all questions, by format.
- Short answer38%329
- MCQ16%135
- Biological term11%97
- Reasoning9.3%81
- Definition6.6%57
- Odd one out4.6%40
- Differentiate3.9%34
- Diagram3.3%29
- Sequencing3.0%26
- Correct the statement1.7%15
- Analogy1.2%10
- Match the following1.0%9
By marks
Share of all questions, by weight.
- 0.5 marks4.8%42
- 0.6 marks0.6%5
- 1 mark84%725
- 2 marks7.7%67
- 3 marks1.6%14
- 5 marks1.7%15
By difficulty
Share of all questions, by rating.
- Easy16%138
- Moderate64%555
- Hard20%175
Diagram load
Chapters where diagram-based questions are most concentrated.
Most diagram-heavy chapters
Share of the chapter's questions that include a diagram.
Year-by-year trends
Shown as a share of each paper, so years stay comparable even though 2021 and 2022 used the reduced semester format with fewer questions.
Short-answer share by year
Percentage of the paper's questions worth less than 2 marks.
Diagram share by year
Percentage of the paper's questions that include a diagram.
Chapter coverage by year
How many questions each chapter contributed to each paper. Darker = more questions.
Chapter × year heatmap
| Chapter | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Absorption by Roots – The Processes Involved | 6 | 7 | 4 | 1 | 4 | 2 | 4 | 3 | 2 | 4 | |
| Cell – The Structural and Functional Unit of Life | 2 | 1 | 1 | ||||||||
| Chemical Coordination in Plants | 9 | 5 | 4 | 4 | 3 | 3 | |||||
| Genetics – Some Basic Fundamentals | 9 | 7 | 6 | 7 | 9 | 6 | 5 | 5 | 6 | 2 | |
| Human Evolution | 6 | 3 | 3 | 3 | 4 | ||||||
| Photosynthesis | 7 | 7 | 8 | 8 | 8 | 9 | 5 | 4 | 5 | 5 | |
| Pollution – A Rising Environmental Problem | 4 | 12 | 10 | 9 | 3 | 8 | 5 | 8 | 9 | ||
| Population – The Increasing Numbers and Rising Problems | 1 | 1 | 2 | 1 | 4 | 4 | 2 | 3 | 2 | ||
| Sense Organs | 15 | 9 | 7 | 6 | 11 | 9 | 4 | 10 | 9 | 7 | |
| Structure of Chromosomes, Cell Cycle and Cell Division | 9 | 10 | 9 | 7 | 5 | 9 | 6 | 5 | 5 | 5 | |
| The Circulatory System | 9 | 12 | 12 | 5 | 11 | 9 | 8 | 12 | 4 | 5 | |
| The Endocrine System | 11 | 9 | 3 | 8 | 4 | 8 | 4 | 5 | 5 | 8 | |
| The Excretory System | 4 | 4 | 8 | 6 | 7 | 4 | 4 | 4 | 4 | 4 | |
| The Nervous System | 4 | 8 | 8 | 6 | 6 | 7 | 5 | 5 | 6 | 9 | |
| The Reproductive System | 10 | 11 | 10 | 11 | 12 | 8 | 4 | 5 | 11 | ||
| Transpiration | 8 | 2 | 9 | 6 | 5 | 13 | 5 | 5 | 4 | 3 |
Most frequently tested topics
Recurring topics across chapters.