Across the seven complete NEET papers we hold (2018, 2020, 2021, 2023, 2024, 2025 and 2026, the 2026 paper being the 21 June re-examination), twelve Biology chapters carried exactly half of all 660 Biology questions: 330. Molecular Basis of Inheritance led Botany with 43 questions, 6.1 a paper, and Biotechnology: Principles and Processes led Zoology with 34, 4.9 a paper. Those twelve chapters are listed first below, then every Botany and Zoology chapter in full.
Which chapters make up half of NEET Biology?
Rank all 39 Biology chapters by the questions they carried, add them from the top, and the running total reaches 330 of 660 at the twelfth chapter.
| # | Chapter | Subject | Questions in 7 papers | Average per paper | Share of Biology | Running share |
|---|---|---|---|---|---|---|
| 1 | Molecular Basis of Inheritance | Botany | 43 | 6.1 | 7% | 7% |
| 2 | Biotechnology: Principles and Processes | Zoology | 34 | 4.9 | 5% | 12% |
| 3 | Cell: The Unit of Life | Botany | 28 | 4.0 | 4% | 16% |
| 4 | Principles of Inheritance and Variation | Botany | 28 | 4.0 | 4% | 20% |
| 5 | Human Reproduction | Zoology | 27 | 3.9 | 4% | 24% |
| 6 | Animal Kingdom | Zoology | 26 | 3.7 | 4% | 28% |
| 7 | Sexual Reproduction in Flowering Plants | Botany | 26 | 3.7 | 4% | 32% |
| 8 | Biomolecules | Zoology | 25 | 3.6 | 4% | 36% |
| 9 | Human Health and Disease | Zoology | 24 | 3.4 | 4% | 40% |
| 10 | Organisms and Populations | Botany | 24 | 3.4 | 4% | 43% |
| 11 | Cell Cycle and Cell Division | Botany | 23 | 3.3 | 3% | 47% |
| 12 | Plant Kingdom | Botany | 22 | 3.1 | 3% | 50% |
Seven are Botany chapters and five are Zoology. Every one of the twelve appeared in all seven papers.
Two cautions before you treat this as a shortcut. First, "half the questions" in seven papers taken together is not half of every paper: the same twelve chapters carried between 42% (2018) and 61% (2025) of the Biology questions in individual papers, and 52% across the last three. Second, the other half is spread across 27 chapters, most of them carrying two or three questions a paper. A student who learns only these twelve is betting against about 47 Biology questions a paper. Read the list as where to start, not where to stop.
Which Botany chapters carry the most marks in NEET?
"Share" is the chapter's part of all 363 questions we filed under Botany. The last column is the average over the three most recent papers (2024, 2025 and 2026).
| # | Chapter | Questions in 7 papers | Average per paper | Share of Botany | Papers it appeared in | Average, 2024–2026 |
|---|---|---|---|---|---|---|
| 1 | Molecular Basis of Inheritance | 43 | 6.1 | 12% | 7 of 7 | 5.3 |
| 2 | Cell: The Unit of Life | 28 | 4.0 | 8% | 7 of 7 | 5.0 |
| 3 | Principles of Inheritance and Variation | 28 | 4.0 | 8% | 7 of 7 | 4.0 |
| 4 | Sexual Reproduction in Flowering Plants | 26 | 3.7 | 7% | 7 of 7 | 4.3 |
| 5 | Organisms and Populations | 24 | 3.4 | 7% | 7 of 7 | 3.0 |
| 6 | Cell Cycle and Cell Division | 23 | 3.3 | 6% | 7 of 7 | 2.3 |
| 7 | Plant Kingdom | 22 | 3.1 | 6% | 7 of 7 | 2.7 |
| 8 | Plant Growth and Development | 20 | 2.9 | 6% | 6 of 7 | 3.3 |
| 9 | Morphology of Flowering Plants | 19 | 2.7 | 5% | 7 of 7 | 3.0 |
| 10 | Photosynthesis in Higher Plants | 19 | 2.7 | 5% | 7 of 7 | 3.3 |
| 11 | Anatomy of Flowering Plants | 16 | 2.3 | 4% | 6 of 7 | 1.3 |
| 12 | Biological Classification | 15 | 2.1 | 4% | 6 of 7 | 2.7 |
| 13 | Biodiversity and Conservation | 14 | 2.0 | 4% | 6 of 7 | 3.0 |
| 14 | Ecosystem | 14 | 2.0 | 4% | 7 of 7 | 2.0 |
| 15 | Environmental Issues | 11 | 1.6 | 3% | 4 of 7 | 0.0 |
| 16 | Microbes in Human Welfare | 10 | 1.4 | 3% | 6 of 7 | 2.0 |
| 17 | Respiration in Plants | 10 | 1.4 | 3% | 7 of 7 | 1.3 |
| 18 | Mineral Nutrition | 7 | 1.0 | 2% | 4 of 7 | 0.0 |
| 19 | The Living World | 6 | 0.9 | 2% | 4 of 7 | 1.3 |
| 20 | Transport in Plants | 5 | 0.7 | 1% | 4 of 7 | 0.0 |
| 21 | Reproduction in Organisms | 2 | 0.3 | 1% | 1 of 7 | 0.0 |
| 22 | Strategies for Enhancement in Food Production (plant breeding) | 1 | 0.1 | 0% | 1 of 7 | 0.0 |
Shares are rounded to whole numbers, so they do not add to exactly 100.
Molecular Basis of Inheritance is the single heaviest chapter in all of NEET: 6.1 questions a paper, about 25 marks. Transcription and translation alone carried 22 of its 43 questions, more than most whole chapters. Put it together with Principles of Inheritance and Variation and genetics carried 71 questions, 10.1 a paper, or 11% of all Biology.
The ecology chapters (Organisms and Populations, Ecosystem, Biodiversity and Conservation, Environmental Issues) carried 63 questions, 9.0 a paper. Plant physiology (Photosynthesis, Respiration, Plant Growth, Mineral Nutrition, Transport in Plants) carried 61, 8.7 a paper. Those two blocks are each close to genetics in size, and students tend to give them far less time.
Which Zoology chapters carry the most marks in NEET?
"Share" is the chapter's part of all 297 questions we filed under Zoology.
| # | Chapter | Questions in 7 papers | Average per paper | Share of Zoology | Papers it appeared in | Average, 2024–2026 |
|---|---|---|---|---|---|---|
| 1 | Biotechnology: Principles and Processes | 34 | 4.9 | 11% | 7 of 7 | 5.0 |
| 2 | Human Reproduction | 27 | 3.9 | 9% | 7 of 7 | 4.7 |
| 3 | Animal Kingdom | 26 | 3.7 | 9% | 7 of 7 | 3.7 |
| 4 | Biomolecules | 25 | 3.6 | 8% | 7 of 7 | 4.0 |
| 5 | Human Health and Disease | 24 | 3.4 | 8% | 7 of 7 | 4.7 |
| 6 | Structural Organisation in Animals | 22 | 3.1 | 7% | 7 of 7 | 3.3 |
| 7 | Evolution | 21 | 3.0 | 7% | 7 of 7 | 3.7 |
| 8 | Biotechnology and its Applications | 19 | 2.7 | 6% | 7 of 7 | 2.0 |
| 9 | Chemical Coordination and Integration | 16 | 2.3 | 5% | 7 of 7 | 3.3 |
| 10 | Body Fluids and Circulation | 15 | 2.1 | 5% | 7 of 7 | 2.3 |
| 11 | Reproductive Health | 14 | 2.0 | 5% | 7 of 7 | 1.7 |
| 12 | Locomotion and Movement | 13 | 1.9 | 4% | 6 of 7 | 1.7 |
| 13 | Breathing and Exchange of Gases | 11 | 1.6 | 4% | 6 of 7 | 1.0 |
| 14 | Excretory Products and their Elimination | 10 | 1.4 | 3% | 6 of 7 | 1.3 |
| 15 | Neural Control and Coordination | 9 | 1.3 | 3% | 5 of 7 | 1.0 |
| 16 | Digestion and Absorption | 8 | 1.1 | 3% | 4 of 7 | 0.0 |
| 17 | Strategies for Enhancement in Food Production (animal breeding) | 3 | 0.4 | 1% | 3 of 7 | 0.0 |
The two biotechnology chapters together carried 53 questions, 7.6 a paper, or 8% of all Biology. Within Biotechnology: Principles and Processes, restriction enzymes and vectors carried 17 questions on their own.
The seven human physiology chapters (Body Fluids, Breathing, Excretion, Locomotion, Neural Control, Chemical Coordination, Digestion) carried 82 questions, 11.7 a paper, 12% of Biology. Individually none of them is large; together they are the biggest block in Zoology. That is the classic trap: each looks skippable on its own, and skipping all of them costs about twelve questions a paper.
Several Zoology chapters have been carrying more in the recent papers: Human Health and Disease (3.4 over seven papers, 4.7 over the last three), Human Reproduction (3.9 to 4.7) and Chemical Coordination and Integration (2.3 to 3.3). Three papers is a small base, so treat that as a nudge to give them full weight, not as a forecast.
Why does Botany show more questions than Zoology?
The paper's own sections are equal, 45 Botany and 45 Zoology in the current pattern. Our split is by chapter, and it comes out at 363 Botany questions (55%) and 297 Zoology (45%). The difference is in how chapters are filed: we put the genetics chapters, the cell chapters and Organisms and Populations under Botany, and Biomolecules under Zoology, as they are commonly taught. Questions from these chapters do not always sit in the section their chapter is filed under. Strategies for Enhancement in Food Production appears in both lists because we split it into plant breeding and animal breeding.
So compare chapters within a subject freely, but do not read the 55/45 split as the paper favouring Botany.
Which NEET Biology chapters have not been asked since 2024?
Seven chapters carried 37 questions in the 2018 to 2023 papers, 9.3 a paper, and none in 2024, 2025 or 2026: Environmental Issues, Mineral Nutrition, Transport in Plants, Reproduction in Organisms, both halves of Strategies for Enhancement in Food Production, and Digestion and Absorption. Reproduction in Organisms has not appeared since 2018.
A clean break at the same year looks like a change in the syllabus, but check the syllabus itself rather than this table. The NEET page lists the chapters we prepare against, and the National Medical Commission publishes the syllabus each cycle. When you practise on a 2018 to 2023 paper, about one Biology question in ten in those years came from these chapters.
What kind of Biology questions does NEET ask?
Biology is where the question kinds change. Of the 660 Biology questions, 426 (65%) were plain single-correct, 108 (16%) were match-the-following, 105 (16%) were statement-based and 21 (3%) were assertion-reason. In Zoology, statement and matching questions together were 38% of the subject; in Botany, 28%.
These are the questions that punish a half-read NCERT line, because a single wrong pairing or statement changes the option. Chapters such as Animal Kingdom, Human Health and Disease, and Chemical Coordination carried six or seven matching questions each. Practise matching and statement questions as a kind, timed, and read our post on whether NCERT is enough for NEET for how to read the book so these questions are easy.
How we counted
Each question in each complete NEET paper we hold was classified to the NCERT-based chapter and topic it tests, and filed under Botany or Zoology by its chapter. We then counted the questions in each chapter, by paper and in total. Papers with pages missing from the official file are excluded, which is why our set is these seven: 2018, 2020, 2021, 2023, 2024, 2025 and 2026, one paper for each year. The 2026 paper is the re-examination held on 21 June 2026, after the 3 May paper was cancelled.
Before you rely on the numbers:
- The papers are not all the same size. The 2021, 2023 and 2024 papers had an optional Section B in each subject, so Biology printed 100 questions, of which a student answered 90. The other four printed 90. We counted every printed question, which is why the Biology total is 660, 94.3 a paper. See the NEET pattern and what changed.
- Seven papers is a small sample. Molecular Basis of Inheritance carried nine questions in 2021 and two in 2026. Single-year swings that large are normal.
- The classification is ours. A question on DNA fingerprinting could be filed under molecular biology or biotechnology. The broad picture would not change; individual counts might move by one or two.
- The mix changes year to year. Nothing here predicts the next paper.
How should I use NEET Biology weightage in my preparation?
- Make the twelve chapters bulletproof first. Every one appeared in every paper, and together they carried half the Biology questions. Genetics, biotechnology, the cell chapters and the two reproduction chapters are the core of the core.
- Do not stop at twelve. The remaining chapters averaged two to three questions a paper each. NEET Biology is read every line, every chapter; the weightage only tells you the order.
- Treat human physiology and ecology as blocks. Neither has one big chapter, both are bigger in total than most single chapters, and both are easy to underrate.
- Track Botany and Zoology separately in your mocks. A strong Zoology can hide a weak Botany until it is too late, and the chapters you lose marks in are rarely the ones you expect. Our guide to analysing a mock test shows how.
- Put every wrong Biology answer in a mistake book. Most Biology errors are a single misremembered line, and they come back if you do not. See why a mistake book beats your notes.
The Nikaalle 52-week plan weights revision by how many marks each chapter carries, and shows Botany and Zoology as two subjects; the plans page has the details. The companion posts cover Physics and Chemistry.
Frequently asked questions
Which chapter has the highest weightage in NEET Biology?
Molecular Basis of Inheritance, with 43 questions across the seven papers we counted, 6.1 a paper, or 7% of all Biology. Transcription and translation was its most-asked topic, with 22 questions.
Which chapters make up 50% of NEET Biology?
Twelve: Molecular Basis of Inheritance, Biotechnology: Principles and Processes, Cell: The Unit of Life, Principles of Inheritance and Variation, Human Reproduction, Animal Kingdom, Sexual Reproduction in Flowering Plants, Biomolecules, Human Health and Disease, Organisms and Populations, Cell Cycle and Cell Division, and Plant Kingdom. Together they carried 330 of 660 Biology questions.
Which Zoology chapter is most important for NEET?
Biotechnology: Principles and Processes, with 34 questions in seven papers, 4.9 a paper. Human Reproduction (27) and Animal Kingdom (26) come next.
Is human physiology important for NEET?
Yes. Its seven chapters carried 82 questions across seven papers, 11.7 a paper, or 12% of Biology. No single chapter is large, which is why it is easy to underrate.
Is genetics important for NEET?
It is the heaviest area in Biology. Molecular Basis of Inheritance and Principles of Inheritance and Variation together carried 71 questions, 10.1 a paper, or 11% of all Biology questions.
Sources
- Nikaalle analysis of 7 previous-year NEET papers: 2018, 2020, 2021, 2023, 2024, 2025 and 2026 (method above)
- National Testing Agency, NEET (UG): https://neet.nta.nic.in
- National Medical Commission (syllabus): https://www.nmc.org.in
- NCERT: https://ncert.nic.in
Checked against the official sources on 25 October 2026.