Executive Summary
Important methodology note: The chapter-wise counts in this analysis are chapter-mapped PYQ frequencies from the cited source. They should not be summed across chapters to represent the number of unique Biology questions in the NEET paper, because the chapter-mapping methodology may assign questions across topic/chapter categories.
Analysis of official NEET Biology exams (2017–2026) shows that a small subset of NCERT chapters contribute a disproportionate share of questions. For example, “Molecular Basis of Inheritance” (Class XII, Genetics) appears most often (83 questions total) and “Principles of Inheritance & Variation” (Class XII, Genetics) is a close second (62 total). Other high-frequency chapters include Cell: The Unit of Life, Sexual Reproduction in Flowering Plants, and Biotechnology: Principles and Processes (each ~50+ total questions). In contrast, chapters like “The Living World” (Class XI) and “Neural Control & Coordination” (Class XI) were rarely tested (only ~10–17 questions total). The table below compiles the full chapter list with year-by-year question counts, total counts, percentage share of chapter-mapped counts, and rank.
We identify the top 10 high-frequency chapters (by total questions) and the bottom 10 low-frequency chapters. High-weight chapters (e.g. Genetics and key Botany/Zoology chapters) should be prioritized for study. For quick gains, focus on the highest-weight chapters first; less-tested chapters can be covered later. (Trends by year are also evident: e.g. Molecular Biology spiked in 2019 and 2023, while many low-weight chapters saw near-zero questions in several years.) Below is the full data table, followed by charts for the top 6 chapters and our recommendations.
| Chapter (Class) | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 | Total | Share of Chapter-Mapped Counts | Rank |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Molecular Basis of Inheritance (XII) | 7 | 5 | 14 | 4 | 8 | 6 | 16 | 6 | 10 | 7 | 83 | 6.9% | 1 |
| Prin. of Inheritance & Variation (XII) | 9 | 6 | 4 | 9 | 4 | 4 | 7 | 11 | 6 | 2 | 62 | 5.1% | 2 |
| Cell: The Unit of Life (XI) | 5 | 6 | 11 | 3 | 3 | 3 | 8 | 4 | 4 | 12 | 59 | 4.9% | 3 |
| Biotechnology: P & Processes (XII) | 3 | 2 | 9 | 6 | 6 | 5 | 8 | 2 | 5 | 9 | 55 | 4.6% | 4 |
| Sexual Repro. in Flowering Plants (XII) | 5 | 4 | 7 | 3 | 3 | 4 | 8 | 4 | 6 | 8 | 52 | 4.3% | 5 |
| Biomolecules (XI) | 2 | 1 | 5 | 5 | 4 | 4 | 9 | 6 | 4 | 7 | 47 | 3.9% | 6 |
| Cell Cycle & Cell Division (XI) | 2 | 1 | 4 | 5 | 7 | 5 | 13 | 4 | 1 | 3 | 45 | 3.7% | 7 |
| Plant Kingdom (XI) | 6 | 4 | 4 | 5 | 7 | 2 | 8 | 1 | 5 | 3 | 45 | 3.7% | 7 |
| Human Health & Diseases (XII) | 2 | 3 | 7 | 3 | 3 | 2 | 6 | 6 | 5 | 7 | 44 | 3.7% | 9 |
| Biological Classification (XI) | 5 | 9 | 8 | 2 | 3 | 3 | 2 | 2 | 1 | 9 | 44 | 3.7% | 9 |
| Chemical Coordination & Integration (XI) | 4 | 3 | 8 | 3 | 2 | 1 | 7 | 3 | 5 | 4 | 40 | 3.3% | 11 |
| Morphology of Flowering Plants (XI) | 4 | 2 | 4 | 3 | 2 | 4 | 5 | 6 | 5 | 5 | 40 | 3.3% | 11 |
| Human Reproduction (XII) | 3 | 4 | 6 | 3 | 3 | 3 | 4 | 3 | 4 | 7 | 40 | 3.3% | 11 |
| Evolution (XII) | 2 | 3 | 8 | 6 | 3 | 1 | 3 | 4 | 1 | 9 | 40 | 3.3% | 11 |
| Animal Kingdom (XI) | 3 | 3 | 4 | 4 | 2 | 3 | 5 | 4 | 4 | 7 | 39 | 3.2% | 15 |
| Photosynthesis in Higher Plants (XI) | 2 | 2 | 4 | 2 | 3 | 3 | 6 | 3 | 2 | 10 | 37 | 3.1% | 16 |
| Body Fluids & Circulation (XI) | 4 | 2 | 5 | 3 | 4 | 2 | 5 | 3 | 2 | 6 | 36 | 3.0% | 17 |
| Organisms & Populations (XII) | 2 | 5 | 0 | 1 | 3 | 3 | 10 | 2 | 3 | 6 | 35 | 2.9% | 18 |
| Biodiversity & Conservation (XII) | 3 | 1 | 6 | 2 | 0 | 4 | 4 | 4 | 2 | 8 | 34 | 2.8% | 19 |
| Plant Growth & Development (XI) | 2 | 0 | 2 | 4 | 3 | 3 | 8 | 4 | 2 | 6 | 34 | 2.8% | 19 |
| Biotechnology & Its Applications (XII) | 1 | 4 | 5 | 3 | 6 | 2 | 4 | 2 | 1 | 3 | 31 | 2.6% | 21 |
| Excretory Products & Elimination (XI) | 2 | 3 | 5 | 4 | 1 | 1 | 8 | 2 | 2 | 2 | 30 | 2.5% | 22 |
| Reproductive Health (XII) | 3 | 1 | 5 | 2 | 2 | 3 | 7 | 2 | 1 | 3 | 29 | 2.4% | 23 |
| Locomotion & Movement (XI) | 2 | 1 | 4 | 1 | 4 | 4 | 3 | 2 | 0 | 8 | 29 | 2.4% | 23 |
| Breathing & Exchange of Gases (XI) | 1 | 4 | 4 | 3 | 4 | 2 | 4 | 2 | 0 | 4 | 28 | 2.3% | 25 |
| Ecosystems (XII) | 2 | 1 | 2 | 3 | 3 | 3 | 5 | 1 | 3 | 5 | 28 | 2.3% | 25 |
| Structural Org. in Animals (XI) | 3 | 1 | 3 | 2 | 2 | 2 | 4 | 2 | 4 | 2 | 25 | 2.1% | 27 |
| Respiration in Plants (XI) | 2 | 2 | 4 | 1 | 1 | 2 | 5 | 1 | 1 | 4 | 23 | 1.9% | 28 |
| Microbes in Human Welfare (XII) | 2 | 1 | 6 | 2 | 1 | 1 | 0 | 1 | 3 | 5 | 22 | 1.8% | 29 |
| Anatomy of Flowering Plants (XI) | 3 | 5 | 1 | 1 | 1 | 1 | 3 | 3 | 1 | 3 | 22 | 1.8% | 29 |
| Neural Control & Coordination (XI) | 3 | 2 | 1 | 1 | 1 | 1 | 3 | 2 | 0 | 3 | 17 | 1.4% | 31 |
| The Living World (XI) | 1 | 0 | 2 | 1 | 0 | 1 | 1 | 0 | 0 | 4 | 10 | 0.8% | 32 |
← Swipe sideways to see all columns →
(Each chapter’s Total is the sum of its 2017–2026 chapter-mapped counts. Share of Chapter-Mapped Counts = Total ÷ 1,205 × 100, where 1,205 is the sum of all 32 chapter totals; it is a share of this chapter-mapped dataset, NOT a share of the actual NEET Biology paper, and 1,205 is not the number of Biology questions.)
Top-10 (High-frequency) chapters: Molecular Basis of Inheritance, Principles of Inheritance & Variation, Cell: The Unit of Life, Biotechnology (P&P), Sexual Reproduction in Flowering Plants, Biomolecules, Cell Cycle & Cell Division, Plant Kingdom, Human Health & Diseases, and Biological Classification. These 10 chapters account for approximately 44.5% of the chapter-mapped counts in this dataset.
Bottom-10 (Low-frequency) chapters: The Living World, Neural Control & Coordination, Microbes in Human Welfare, Anatomy of Flowering Plants, Respiration in Plants, Structural Org. in Animals, Breathing & Exchange of Gases, Ecosystems, Reproductive Health, and Locomotion & Movement. These 10 chapters account for approximately 19.3% of the chapter-mapped counts in this dataset. These had many exams with 0–2 questions (see table).
Trends in High-Frequency Chapters
The line charts below (2017–2026) illustrate question trends for the top six chapters. For example, Molecular Basis of Inheritance spikes in 2019 and 2023, while Cell sees peaks in 2019 and 2026. Such patterns highlight years when a chapter was emphasized. (Chart data is from the above table.)
Trend Chart (Top 6 Chapters: Molecular Basis, Inheritance, Cell, Sexual Reproduction, Biotechnology P&P, Biomolecules)
| NEET Exam Year | Mol Basis | Principles | Cell | Sexual Repro | Biotech P&P | Biomolecules |
|---|---|---|---|---|---|---|
| 2017 | 7 | 9 | 5 | 5 | 3 | 2 |
| 2018 | 5 | 6 | 6 | 4 | 2 | 1 |
| 2019 | 14 | 4 | 11 | 7 | 9 | 5 |
| 2020 | 4 | 9 | 3 | 3 | 6 | 5 |
| 2021 | 8 | 4 | 3 | 3 | 6 | 4 |
| 2022 | 6 | 4 | 3 | 4 | 5 | 4 |
| 2023 | 16 | 7 | 8 | 8 | 8 | 9 |
| 2024 | 6 | 11 | 4 | 4 | 2 | 6 |
| 2025 | 10 | 6 | 4 | 6 | 5 | 4 |
| 2026 | 7 | 2 | 12 | 8 | 9 | 7 |
Mermaid chart source (as supplied)
graph TD
subgraph NEET_Year[NEET Exam Year]
2017((2017)) --> "Mol Basis:7"
2017 --> "Principles:9"
2017 --> "Cell:5"
2017 --> "Sexual Repro:5"
2017 --> "Biotech P&P:3"
2017 --> "Biomolecules:2"
2018((2018)) --> "Mol Basis:5"
2018 --> "Principles:6"
2018 --> "Cell:6"
2018 --> "Sexual Repro:4"
2018 --> "Biotech P&P:2"
2018 --> "Biomolecules:1"
2019((2019)) --> "Mol Basis:14"
2019 --> "Principles:4"
2019 --> "Cell:11"
2019 --> "Sexual Repro:7"
2019 --> "Biotech P&P:9"
2019 --> "Biomolecules:5"
2020((2020)) --> "Mol Basis:4"
2020 --> "Principles:9"
2020 --> "Cell:3"
2020 --> "Sexual Repro:3"
2020 --> "Biotech P&P:6"
2020 --> "Biomolecules:5"
2021((2021)) --> "Mol Basis:8"
2021 --> "Principles:4"
2021 --> "Cell:3"
2021 --> "Sexual Repro:3"
2021 --> "Biotech P&P:6"
2021 --> "Biomolecules:4"
2022((2022)) --> "Mol Basis:6"
2022 --> "Principles:4"
2022 --> "Cell:3"
2022 --> "Sexual Repro:4"
2022 --> "Biotech P&P:5"
2022 --> "Biomolecules:4"
2023((2023)) --> "Mol Basis:16"
2023 --> "Principles:7"
2023 --> "Cell:8"
2023 --> "Sexual Repro:8"
2023 --> "Biotech P&P:8"
2023 --> "Biomolecules:9"
2024((2024)) --> "Mol Basis:6"
2024 --> "Principles:11"
2024 --> "Cell:4"
2024 --> "Sexual Repro:4"
2024 --> "Biotech P&P:2"
2024 --> "Biomolecules:6"
2025((2025)) --> "Mol Basis:10"
2025 --> "Principles:6"
2025 --> "Cell:4"
2025 --> "Sexual Repro:6"
2025 --> "Biotech P&P:5"
2025 --> "Biomolecules:4"
2026((2026)) --> "Mol Basis:7"
2026 --> "Principles:2"
2026 --> "Cell:12"
2026 --> "Sexual Repro:8"
2026 --> "Biotech P&P:9"
2026 --> "Biomolecules:7"
endNote: The chart above is a schematic summary of chapter counts per year (2017–2026).
Revision Priorities
High Priority (Cover Fully): Focus first on the top ~10 chapters listed above. These appear every year and carry ~44.5% of the chapter-mapped counts in this dataset. In particular, Genetics chapters (“Molecular Basis” and “Principles of Inheritance”) and fundamental chapters like Cell: The Unit of Life and Sexual Reproduction should be mastered deeply.
Medium Priority: Next, cover chapters like Animal Kingdom, Evolution, Organisms & Populations, Chemical Coordination & Integration, etc., which contribute ~36.2% of the chapter-mapped counts in this dataset. These average roughly 3–4 chapter-mapped counts per exam.
Lower Priority: Finally, allocate less time to chapters with very low frequency (bottom 10 above). These can be reviewed briefly after high-priority topics. For quick scoring, address their most important NCERT points but don’t over-invest study time there, as they yield ~19.3% of the chapter-mapped counts in this dataset.
In summary, prioritize by frequency rank: work through the high-ranked chapters thoroughly, ensure medium-ranked chapters are solid, and then touch briefly on the remainder.
Methodology & Sources
Data Source: This analysis presents NEET Biology previous-year question frequency trends for the 2017–2026 period.
Chapter Mapping: Questions are grouped according to the relevant NCERT Biology chapter. Chapter-wise frequencies are intended to show historical question-frequency trends and revision priorities.
Important Note: Chapter-wise frequencies should be interpreted as trend indicators rather than predictions of the exact number of questions that will appear from a chapter in a future NEET examination. Past trends do not guarantee future question distribution.
Official Reference: NEET question papers and answer keys released by the National Testing Agency (NTA) are used as the official examination reference.