The Class 12 Biology page has all seven NCERT resource types for the 2026-27 syllabus: NCERT Solutions, Notes, Formula Sheet, NCERT Book PDF, Exemplar Solutions, Exemplar Book PDF, and Handwritten Notes.
Class 12 Biology NCERT Resources
Students can find all Biology Class 12 NCERT Resources here according to the latest 2026-27 Class 12 Biology syllabus. Each row links to different Biology NCERT resources available on Collegedunia, like NCERT Solutions, Notes, Formula Sheet, Exemplar Solutions, Book PDF, and Handwritten Notes.
Every chapter and every format is free to download.
- Chapters covered: 13 chapters across the CBSE 2026-27 syllabus
- Resource types: 7 resource types per chapter - Solutions, Notes, Formula Sheet, NCERT Book PDF, Exemplar Solutions, Exemplar Book PDF, Handwritten Notes
- Exam alignment: CBSE Class 12 Biology theory paper (70 marks), NEET, AIIMS, CUET-UG Biology
Subject experts build every Class 12 Biology resource on Collegedunia. Each one matches the 2026-27 NCERT. Each one also follows the last five years of CBSE Board and competitive-exam papers.
All NCERT Class 12 Biology Resource Listings
Browse every resource type for Class 12 Biology from one place. Each card below opens its own listing page. That page links to all 14 chapters for that resource. It also links to the combined all-chapters PDF and the 2026-27 NCERT notes.
| Resource | What it gives you | Open all chapters |
|---|---|---|
| NCERT Solutions | Step-by-step answers to every back-exercise question in all chapters. | Open Class 12 Biology NCERT Solutions |
| Notes | Chapter-wise revision notes that shrink the NCERT textbook into short exam-style summaries. | Open Class 12 Biology Notes |
| Formula Sheet | A small 2-column quick-recall sheet with every formula, derivation result, and constant. | Open Class 12 Biology Formula Sheet |
| NCERT Book PDF | The official 2026-27 NCERT textbook. Download it chapter by chapter. | Open Class 12 Biology NCERT Book PDF |
| Exemplar Solutions | Worked answers to every MCQ, MCQ-II, VSA, SA, and LA problem in the official NCERT Exemplar. | Open Class 12 Biology Exemplar Solutions |
| Exemplar Book PDF | The official NCERT Exemplar Problems book. Download it chapter by chapter. | Open Class 12 Biology Exemplar Book PDF |
| Handwritten Notes | Notebook-style, scanned-look revision notes for the last two weeks before the boards. | Open Class 12 Biology Handwritten Notes |
Class 12 Biology Quick Video Walkthrough
Source: Magnet Brains on YouTube
Class 12 Biology Topic Map (2026-27 NCERT)
Here is how the 13 Class 12 Biology chapters group into the CBSE units below.
| Unit | Chapters | What this unit covers |
|---|---|---|
| VI. Reproduction | Ch 1, Ch 2, Ch 3 | Sexual reproduction in flowering plants (pre-fertilisation events, double fertilisation, post-fertilisation events), human reproduction (gametogenesis, menstrual cycle, fertilisation, implantation, parturition), reproductive health (population stabilisation, contraception, ART, STIs). |
| VII. Genetics and Evolution | Ch 4, Ch 5, Ch 6 | Mendelian and post-Mendelian inheritance, sex determination, pedigree analysis, DNA structure and replication, transcription, translation, gene regulation, Human Genome Project, origin and evolution of life including Darwinism and Hardy-Weinberg principle. |
| VIII. Biology and Human Welfare | Ch 7 Human Health and Disease · Ch 8 Microbes in Human Welfare | Human health, immune system, infectious diseases (typhoid, pneumonia, common cold, malaria, amoebiasis, ascariasis, ringworms), AIDS, cancer, drugs and alcohol abuse, microbes in household products, industrial products, sewage treatment, biogas production, biocontrol agents, biofertilisers. |
| IX. Biotechnology and Its Applications | Ch 9 Biotechnology Principles and Processes · Ch 10 Biotechnology and Its Applications | Principles of biotechnology, tools of recombinant DNA technology, processes of recombinant DNA technology, biotechnology applications in agriculture (Bt crops, RNA interference, pest-resistant plants), biotechnology applications in medicine (insulin production, gene therapy, molecular diagnosis), transgenic animals, biosafety issues, biopiracy and patents. |
| X. Ecology and Environment | Ch 11, Ch 12, Ch 13 | Organisms and their environment, population attributes (growth, age distribution, interactions), ecosystem components and productivity, decomposition, energy flow, ecological pyramids, ecological succession, nutrient cycling, biodiversity patterns and loss, conservation strategies (in-situ and ex-situ). |
NCERT Class 12 Biology Deleted Syllabus 2026-27
NCERT has trimmed the 2026-27 Class 12 Biology syllabus to cut the study load for CBSE Boards and NEET. The topics listed below are officially out of the 2026-27 question paper. Skip them while you revise.
| Chapter | Deleted Topics (2026-27) |
|---|---|
| Reproduction in Organisms (formerly Ch 1) | Full chapter removed for 2026-27. Asexual modes and life-cycle patterns are out. |
| Strategies for Enhancement in Food Production (formerly Ch 9) | Full chapter removed. Animal husbandry, plant breeding, and single-cell protein are no longer in scope. |
| Microbes in Human Welfare (Ch 10) | Microbes in industrial production: some sub-parts removed. Sewage treatment stays. |
| Biodiversity and Conservation (Ch 15) | Ecosystem services valuation and biodiversity-hotspots details removed. |
| Environmental Issues (formerly Ch 16) | Full chapter removed. Air pollution, water pollution, and greenhouse effect are dropped from board scope. |
| Biotechnology - Principles (Ch 11) | Restriction enzyme types: some sub-parts removed. |
| Human Reproduction (Ch 2) | Reproductive health programmes: details on government schemes removed. |
The chapter-wise resources linked in the All Chapters index above already flag every deleted line inline. So you never waste revision hours on dropped topics.
Class 12 Biology Chapter-wise Important Questions
The five chapter clusters below carry most of the CBSE 2026 Class 12 Biology paper. They repeat almost every year. The first column lists the long-answer topics that come back as 3-mark and 5-mark questions. The second column lists the application-level questions that appear as 1-3 mark numericals, MCQs, and case-studies in CBSE and NEET UG.
| Chapter Cluster | Important Concepts / Diagrams (3-5 marks) | Important MCQs / Short-Answer (1-2 marks) |
|---|---|---|
| Reproduction (Ch 1-4) | 1. Male and female reproductive system labelled diagrams. 2. Mendel's laws and dihybrid cross. 3. Spermatogenesis and oogenesis flow charts. | Phases of menstrual cycle, structure of ovum / sperm, methods of contraception. |
| Genetics and Evolution (Ch 5-6) | 1. Chromosomal theory of inheritance. 2. DNA replication and transcription mechanism. 3. Hardy-Weinberg principle derivation. | Sex determination types, mutations and types, Darwinian evolution evidence. |
| Biology in Human Welfare (Ch 7-8) | 1. Innate vs acquired immunity comparison. 2. Vaccine types and mechanism of action. 3. Cancer types and detection strategies. | AIDS / HIV life cycle, drugs of abuse, adolescent issues. |
| Biotechnology (Ch 9-10) | 1. PCR steps and applications. 2. Recombinant DNA technology process flow. 3. Bt cotton and golden rice case studies. | Cloning vectors, gene therapy, biosafety issues. |
| Ecology (Ch 11-13) | 1. Energy flow in ecosystem - 10% law derivation. 2. Population growth curves (exponential vs logistic). 3. Nitrogen cycle and carbon cycle flow charts. | Ecological pyramids, food chain types, succession in plants. |
About 50% of the NEET UG 2026 Biology section comes from these five clusters, mostly Genetics and Ecology. The Expert's Solution tab on each chapter page adds NEET-style answer-elimination reasoning. It sits next to the CBSE board-style structured answer.
SUBJECT HUB · CLASS 12 BIOLOGY
Class 12 Biology - Exam Weightage
Class 12 Biology is worth about 160 marks combined across CBSE Boards and NEET UG. It is the single largest scoring block for NEET aspirants.
Class 12 Biology Weightage Snapshot (CBSE 2026 Theory Paper)
The 70-mark CBSE Class 12 Biology theory paper splits unevenly. Genetics and Evolution leads the table at 20 marks. That is about 29% of the theory paper.
| Chapter | Topic | CBSE Marks (2026) | NEET 2025 Qs |
|---|---|---|---|
| Ch 5 | Molecular Basis of Inheritance | 8 marks | 3 |
| Ch 4 | Principles of Inheritance and Variation | 7 marks | 2 |
| Ch 2 | Human Reproduction | 6 marks | 2 |
| Ch 1 | Sexual Reproduction in Flowering Plants | 6 marks | 2 |
| Ch 9 | Biotechnology Principles and Processes | 6 marks | 2 |
| Ch 10 | Biotechnology and Its Applications | 6 marks | 2 |
| Ch 7 | Human Health and Disease | 5 marks | 2 |
| Ch 12 | Ecosystem | 5 marks | 1 |
| Ch 6 | Evolution | 4 marks | 2 |
| Ch 3 | Reproductive Health | 4 marks | 1 |
| Ch 11 | Organisms and Populations | 4 marks | 1 |
| Ch 8 | Microbes in Human Welfare | 4 marks | 1 |
| Ch 13 | Biodiversity and Conservation | 5 marks | 1 |
Class 12 Biology CBSE 2026 Paper Pattern Snapshot
The 70-mark CBSE Class 12 Biology theory paper runs 3 hours and has five sections. Knowing the weight of each section is half the revision plan. Once you know which section a chapter feeds, you can pick the right resource. Use Notes for Section A recall and NCERT Solutions for Sections C and D working.
- Section A (16 questions of 1 mark each): MCQs and assertion-reason. Tests definitions, examples, and one-line facts.
- Section B (5 questions of 2 marks each): Very short answer. One-step questions on processes, mechanisms, and named experiments.
- Section C (7 questions of 3 marks each): Short answer. Diagram-with-labels questions and process-explanation questions sit here.
- Section D (2 case-study questions of 4 marks each): Apply genetics, ecology, or biotechnology to a passage. Sub-parts test how well you read it.
- Section E (3 questions of 5 marks each): Long answer. Full-system descriptions anchor this section, like the reproductive system, photosynthesis pathway, and DNA replication.
The 70-mark theory paper plus the 30-mark internal assessment (practical, project, viva) makes the 100-mark scheme. Internal assessment marks depend on how complete your lab notebook is and how well you prepare for the viva. The theory paper is where your chapter-wise NCERT work really shows.
Where to Start with Class 12 Biology
For first-time study, work in NCERT order. For revision, the six-chapter shortlist below gives you 39 of 70 board marks:
- Chapter 5, Molecular Basis of Inheritance (8 marks): the single highest-weightage chapter. Transcription, translation, and DNA replication diagrams come up in almost every board paper.
- Chapter 4, Principles of Inheritance and Variation (7 marks): Mendel's laws, pedigree analysis, and sex determination repeat every year. Punnett-square problems are common 5-mark slots.
- Chapter 9, Biotechnology Principles and Processes (6 marks): restriction enzymes, gel electrophoresis, and PCR are common MCQ and LA questions on NEET and CBSE.
- Chapter 10, Biotechnology and Its Applications (6 marks): Bt cotton, GMOs, and gene therapy carry steady weightage on both NEET and CBSE.
- Chapter 2, Human Reproduction (6 marks): labelled diagrams (female and male reproductive systems, gametogenesis) give high marks per question.
- Chapter 1, Sexual Reproduction in Flowering Plants (6 marks): double fertilisation, microsporogenesis, megasporogenesis, and embryo development steps come up in every paper.
Which Resource Should You Use When?
Each Class 12 Biology resource on this hub fits a specific revision moment. Use the routine below to pick the right resource for the day.
- Throughout the year (concept-first): read the NCERT Book PDF or the Notes for each chapter. Then try the in-text and end-of-chapter questions before you open the NCERT Solutions.
- 1 month before the boards: work the chapter-wise NCERT Solutions in order. Keep the Notes open whenever a concept slips.
- Within 2 months of NEET / AIIMS / CUET: open the Exemplar Solutions and the Exemplar Book PDF. The Exemplar's MCQ-II and LA sections link NCERT to the competitive-exam paper.
- 2 weeks before the boards: switch to the Handwritten Notes for a second-pass concept revision. Pair them with the Formula Sheet for recall.
- 1 week before the boards: use the Formula Sheet for last-day recall, plus the Handwritten Notes for night-before skimming.
- Morning of the paper: 15 minutes with the Formula Sheet, focused on the constants and the high-weightage chapter equations.
How to Use the NCERT Class 12 Biology Hub Most Effectively
The three-phase plan below covers the full year. Change the timings if your boards are more than 12 months away.
5-STEP METHOD · CBSE TOPPER ROUTINE
How to Use the Class 12 resource hub - Class 12 Biology
- 1 Read the chapter first. Open the NCERT Book PDF or chapter Notes. The resource assumes you already understand the concepts.
- 2 Try each question on your own. Write the working in a notebook before you open the answer. Just reading answers does not build exam skill.
- 3 Compare your working to the resource. Mark every step where your method was different. Those are the spots that lose marks on the board paper.
- 4 Flag questions taking over 7 minutes. These go on the re-attempt list for the final-week revision pass.
- 5 Rotate across all 7 resource types each week. Notes for concepts, Solutions for back-exercise, Formula Sheet for recall, Exemplar for harder problems, Handwritten Notes for board feel, NCERT Book PDF for the source text, and PYQs for exam shape.
- Months 1-6 (concept phase): read every chapter of the NCERT Book PDF and try the in-text questions. Then check your work against the Notes and the NCERT Solutions. Skip the Exemplar for now.
- Months 7-10 (application phase): redo the NCERT back-exercise without help. For the high-weightage chapters, also try the SA and LA Exemplar problems and check them against the Exemplar Solutions.
- Months 11-12 (revision phase): switch to the Notes for chapter-wise concept revision. Move to the Handwritten Notes in the last two weeks. Use the Formula Sheet in the final week and on board day.
NCERT Class 12 Biology Resource-by-Resource Reading Sequence
Most students do not realise how much the reading order matters. The NCERT Class 12 Biology hub gives you seven resource types. Opening them in the wrong order wastes study time. The order below matches what CBSE toppers say works for them.
- First read of a fresh chapter: open the NCERT Book PDF. Its worked examples and in-text questions teach the chapter the way CBSE examiners want to see it written back. Do not open the Notes or the Solutions yet.
- After the first read: open the NCERT Solutions for the back-exercise. Try every question on your own first, then check the working. Mark every question that took more than 5 minutes.
- Once the chapter feels familiar: open the Notes for a shorter second read. The Notes are the chapter at 30% length. They sharpen your concept summary before the next revision pass.
- For competitive exam prep: open the Exemplar Book PDF and the Exemplar Solutions together. The harder MCQ-II, SA, and LA problems link the NCERT back-exercise to a NEET / AIIMS / CUET paper.
- In the last two weeks: switch to the Handwritten Notes. The notebook-style format helps faster recall in the exam itself. Keep a blank sheet of paper handy to re-draw diagrams from memory.
- In the final week: open only the Formula Sheet. By now the concepts should be firm in your head. The Formula Sheet is just the recall layer for last-day reference.
This order is not a fixed rule. Some chapters work better with a Notes-first read, mostly the heavier theory chapters. Others work better with a NCERT Book PDF read, mostly the worked-example-heavy chapters. The pattern above is a good starting point, not a rule.
Common Mistakes Class 12 Biology Students Make Across Chapters
- Confusing autosomal dominant and autosomal recessive inheritance: Chapter 4 students often misread a pedigree. The autosomal recessive pattern skips generations. The autosomal dominant pattern shows up in every generation. Always mark the parents' phenotype before you predict the children's.
- Mixing up transcription and translation directions: Chapter 5 students reverse the 5' to 3' direction in the transcription step. mRNA is made 5' to 3', using the template strand read 3' to 5'.
- Treating menstrual cycle phases as fixed dates: Chapter 2 questions ask for the hormone change at a phase, not a date. Ovulation brings an LH surge around day 14 of a 28-day cycle. But the question asks which hormone peaks, not which calendar day.
- Forgetting that Hardy-Weinberg needs five conditions: Chapter 6 students often list only no mutation and random mating. The full set also needs no migration, no genetic drift, no selection, and a large population. CBSE cuts marks for an incomplete list.
- Writing 'evolution' when the question asks for 'speciation': Chapter 6 uses both terms. Evolution is the change in allele frequencies over time. Speciation is the making of new species. Read the verb carefully before you answer.
- Missing the difference between in-situ and ex-situ conservation: Chapter 13 students often list a zoo as in-situ. Zoos and seed banks are ex-situ. Biosphere reserves and national parks are in-situ. The CBSE marking scheme cuts marks for the mismatch.
- Skipping the labelled diagram on reproduction questions: Chapters 1 and 2 give more marks for labelled diagrams than for prose. A full labelled diagram of the human female reproductive system or a typical anatropous ovule is the 3-mark backbone of those questions.
Student Pulse: What 15,290 Class 12 Biology Students Told Us
What 15,290 students told us about their Class 12 Biology full-syllabus preparation
- 68% of students rated Chapter 5 Molecular Basis of Inheritance as the hardest chapter. Next came Chapter 4 Principles of Inheritance and Variation at 57% and Chapter 9 Biotechnology Principles and Processes at 51%.
- Most-skipped chapter: Chapter 13 Biodiversity and Conservation, skipped by about 28% of students even though it carries 5 marks. Toppers called this an easy win, since you can learn the in-situ vs ex-situ table in under an hour.
- Toppers said that using the Expert's Solution tab on every Chapter 5 Molecular Basis of Inheritance problem added 4-6 marks to their 70-mark theory paper score. Most of that came from the transcription-translation diagram-and-label answers.
- The average Class 12 Biology student spent 46 hours across the 13 chapters to finish the NCERT back-exercise once. Chapters 4, 5, 9, and 10 took the most time per question.
Also Check: Related Class 12 Resources
- Also Check: CBSE Class 12 Biology chapter notes hub on Collegedunia Exams
- Also Check: CBSE Class 12 exam pattern, dates, and full-subject hub
- Also Check: CBSE Class 12 Syllabus 2026-27
- Also Check: NEET 2026 exam information
- Also Check: NEET 2026 Syllabus
- Also Check: AIIMS MBBS 2026 information
- Also Check: CUET-UG 2026 information
Topper-tested takeaways for Class 12 Biology Subject Hub
- Use the hub to plan your year-long study calendar. The seven resource types above each fit a different phase of prep.
- Do not download every resource on day one. Pull each resource into your study folder only when you are about to use it.
- The Genetics and Evolution block carries 20 of the 70 marks. Give those chapters a bigger study window.
- Bookmark the hub itself. The single chapter index is the fastest way to find any chapter's resource during revision.
Class 12 Biology FAQs
Ques. What does the Class 12 Biology hub on Collegedunia cover?
Ans. The NCERT Class 12 Biology hub brings together all seven NCERT resource types (Solutions, Notes, Formula Sheet, NCERT Book PDF, Exemplar Solutions, Exemplar Book PDF, Handwritten Notes) for every chapter of the 2026-27 Class 12 Biology syllabus. It runs from Chapter 1 Sexual Reproduction in Flowering Plants through Chapter 13 Biodiversity and Conservation. Every resource is free to download.
Ques. Are these Class 12 Biology resources aligned with the 2026-27 NCERT?
Ans. Yes. Every resource on this hub follows the current 2026-27 NCERT. Where content was cut from the older edition, the affected resources carry an inline callout that flags the change.
Ques. How many chapters are there in Class 12 Biology per the 2026-27 NCERT?
Ans. Class 12 Biology has 13 chapters across the CBSE units: Reproduction (Ch 1, Ch 2, Ch 3), Genetics and Evolution (Ch 4, Ch 5, Ch 6), Biology and Human Welfare (Ch 7, Ch 8), Biotechnology and Its Applications (Ch 9, Ch 10), Ecology and Environment (Ch 11, Ch 12, Ch 13). The Topic Map table above lists every chapter under its unit.
Ques. Which Class 12 Biology chapter has the highest CBSE board weightage?
Ans. Genetics and Evolution is the heaviest unit at 20 marks. The Weightage Snapshot table above shows each chapter's mark share, so you can plan your revision around the high-scoring chapters.
Ques. Which Class 12 Biology resource should I open first?
Ans. For first-time study, open the NCERT Book PDF or the Notes. For revision, open the Notes first, then the NCERT Solutions. Keep the Formula Sheet open as a quick-recall reference. The Which Resource Should You Use When section above lays out the full year-long routine.
Ques. Are these Class 12 Biology resources available in Hindi medium?
Ans. Yes. Every resource comes with a Hindi-medium download next to the English version. The Hindi files use NCERT's own technical terms (Jaiv Vigyan).
Ques. Are these Class 12 Biology resources useful for NEET / AIIMS / CUET preparation?
Ans. Yes. The resource mix on this hub is built for both CBSE and competitive-exam prep. The NCERT Solutions and Notes focus on CBSE. The Exemplar Solutions and Exemplar Book PDF push the difficulty up to NEET / AIIMS / CUET level. Use both layers based on which exam you are preparing for.
Ques. What does Class 12 Biology cover?
Ans. Class 12 Biology covers 5 CBSE units across 13 chapters: Reproduction (Ch 1, Ch 2, Ch 3), Genetics and Evolution (Ch 4, Ch 5, Ch 6), Biology and Human Welfare (Ch 7, Ch 8), Biotechnology and Its Applications (Ch 9, Ch 10), Ecology and Environment (Ch 11, Ch 12, Ch 13). The 70-mark theory paper plus the 30-mark internal assessment together make 100 marks.
Ques. Which is the most-scoring chapter in Class 12 Biology?
Ans. The chapters in the Genetics and Evolution block carry the largest share of the 70-mark paper. Among single chapters, the priority six in the Where to Start section above together give 39 of 70 board marks.
Ques. How should I structure my Class 12 Biology preparation?
Ans. Build chapter by chapter, and put the high-weightage units first. Use the NCERT Book and Notes for concepts, the NCERT Solutions for the back-exercise, the Exemplar for harder practice, and the Formula Sheet for the last week. The full-year plan above shows the concept, application, and revision arc that most toppers follow.
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