The Class 12 Biology NCERT Exemplar Solutions (2026-27 syllabus) are worked-out answers to every MCQ, MCQ-II, VSA, SA, and LA problem in the NCERT Exemplar Problems publication. Each chapter ships as a free downloadable PDF with the step-by-step working a NEET / AIIMS / CUET aspirant needs to crack the harder Exemplar problem set.
- Chapters covered: 13 chapters, identical numbering to the main NCERT textbook
- Format: chapter-wise PDFs with one worked solution per Exemplar problem
- Question coverage: every MCQ, MCQ-II, VSA, SA, and LA problem from the official NCERT Exemplar publication
- Exam alignment: CBSE Class 12 Biology theory paper (70 marks), NEET, AIIMS, CUET-UG Biology
Every solution in this Collegedunia Class 12 Biology NCERT Exemplar Solutions compilation is curated by subject experts, mapped to the 2026-27 NCERT Exemplar, and refined against the NEET / AIIMS / CUET-style working patterns examiners reward.
Class 12 Biology NCERT Exemplar Solutions: All Chapters
Every chapter of the 2026-27 Class 12 Biology NCERT Exemplar, with the chapter-specific worked-solutions PDF linked on each row.
How will Collegedunia's Class 12 Biology NCERT Exemplar Solutions Help You?
The Exemplar Solutions take you beyond the NCERT back-exercise into the conceptual depth competitive exams test. Used after the back-exercise and before mock tests, they bridge the gap between board-level fluency and competitive-exam readiness.
- Every Exemplar problem worked end to end: MCQ, MCQ-II (multi-correct), VSA, SA, and LA - every question in the official NCERT Exemplar publication carries a worked solution.
- 2026-27 NCERT Exemplar alignment: every solution matches the latest Exemplar print; rationalised content is flagged with an inline callout.
- Two-tab Solution format: a short Solution showing the minimum working a board examiner expects, plus an expanded Expert's Solution showing the longer, competitive-exam-style reasoning.
- Alternative methods shown: wherever a problem admits more than one approach, both methods are sketched so you can pick the one that matches your working style.
- Cross-resource navigation: jump from any Exemplar Solution into the same chapter's Notes, NCERT Solutions, Formula Sheet, or Handwritten Notes in one click.
- Verified by subject experts: every solution reviewed against the official Exemplar key and the latest NEET / AIIMS / CUET marking patterns.
What 15,290 students told us about their Class 12 Biology Exemplar Solutions usage
Source: Magnet Brains on YouTube
Class 12 Biology NCERT Exemplar Solutions Topic Map (Coverage)
How the 13 Exemplar chapters group into the CBSE units below. The Exemplar Solutions cover every problem in the source Exemplar publication, in NCERT order.
| Unit | Chapters | What this unit Exemplar Solutions cover |
|---|---|---|
| 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
The NCERT 2026-27 syllabus for Class 12 Biology has been rationalised by the examination authority to reduce content load for CBSE Boards and NEET. The drops listed below are officially out of the 2026-27 question paper, so skip these while revising.
| Chapter | Deleted Topics (2026-27) |
|---|---|
| Reproduction in Organisms (formerly Ch 1) | Full chapter removed in the 2026-27 rationalisation - 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 no longer in scope. |
| Microbes in Human Welfare (Ch 10) | Microbes in industrial production - some sub-parts removed; sewage treatment retained. |
| Biodiversity and Conservation (Ch 15) | Ecosystem services valuation and hotspots-of-biodiversity details removed. |
| Environmental Issues (formerly Ch 16) | Full chapter removed - air pollution, water pollution, greenhouse effect dropped from board scope. |
| Biotechnology - Principles (Ch 11) | Restriction enzyme types (sub-parts) - some details 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 don't waste revision hours on dropped topics.
Class 12 Biology Chapter-wise Important Questions
The five chapter clusters below carry the bulk of the CBSE 2026 Class 12 Biology paper and repeat almost every year. The first column lists the long-answer topics that recur as 3-mark and 5-mark questions; the second column lists the application-level questions that appear as 1-3 mark numericals / MCQs / 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. |
Roughly 50% of the NEET UG 2026 Biology section draws from these five clusters, especially Genetics and Ecology. The Expert's Solution tab on each chapter page adds the NEET-style answer-elimination reasoning alongside the CBSE board-style structured answer.
EXEMPLAR SOLUTIONS · CLASS 12 BIOLOGY
Class 12 Biology - Exam Weightage
Class 12 Biology contributes roughly 160 marks combined across CBSE Boards and NEET UG, the single largest scoring block for medical-entrance aspirants.
Class 12 Biology Weightage Snapshot (CBSE 2026 Theory Paper)
Exemplar Solutions effort scales with chapter weightage. Genetics and Evolution delivers 20 marks of the 70-mark paper - also where the bulk of the harder Exemplar problems sit.
| 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 is split into five sections. Knowing the section-by-section weight is half the revision plan; once you know which section a chapter feeds, you can pick the right resource (Notes for Section A recall, 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): Application of genetics, ecology, or biotechnology to a passage; sub-parts test interpretation.
- Section E (3 questions of 5 marks each): Long answer; full-system descriptions (reproductive system, photosynthesis pathway, DNA replication) anchor this section.
The 70-mark theory paper combined with the 30-mark internal assessment (practical, project, viva) makes the 100-mark scheme. Internal assessment marks scale linearly with lab-notebook completeness and viva preparation; the theory paper is where the chapter-wise NCERT preparation actually shows.
Where to Start in the Class 12 Biology NCERT Exemplar Solutions Index
Start with the six high-weightage chapters where worked Exemplar practice delivers the largest competitive-exam mark boost. Together these six chapters cover 39 of 70 board marks:
- Chapter 5, Molecular Basis of Inheritance (8 marks): the single highest-weightage chapter. Transcription, translation, and DNA replication diagrams are board-paper staples.
- Chapter 4, Principles of Inheritance and Variation (7 marks): Mendel's laws, pedigree analysis, and sex determination repeat year on year. Punnett-square problems are routine 5-mark slots.
- Chapter 9, Biotechnology Principles and Processes (6 marks): restriction enzymes, gel electrophoresis, and PCR are routine MCQ + LA combinations on NEET and CBSE.
- Chapter 10, Biotechnology and Its Applications (6 marks): Bt cotton, GMOs, and gene therapy carry consistent weightage on both NEET and CBSE.
- Chapter 2, Human Reproduction (6 marks): labelled diagrams (female and male reproductive systems, gametogenesis) deliver high marks per question.
- Chapter 1, Sexual Reproduction in Flowering Plants (6 marks): double fertilisation, microsporogenesis, megasporogenesis, and embryo development steps recur in every paper.
Class 12 Biology NCERT Exemplar Solutions PDF Formats
- HD print-ready PDF: high-resolution typesetting for the printed problem-and-solution booklet.
- Standard download PDF: smaller file size for phone reading.
- Hindi-medium Exemplar Solutions PDF: chapter-wise Hindi translations using NCERT's own technical vocabulary (Jaiv Vigyan).
- Combined all-chapters PDF: one file with every chapter's Exemplar Solutions back to back.
- MCQ key + worked solutions: the MCQ key sits at the front of each chapter's PDF for quick verification, with the full worked solutions following.
How Class 12 Biology NCERT Exemplar Solutions Pair with the Other Resources
- Class 12 Biology Exemplar Book PDF: the source problem set; open this alongside the Solutions for the question text.
- Class 12 Biology NCERT Solutions: the back-exercise worked answers; finish these first before opening the Exemplar.
- Class 12 Biology Notes: the concept layer; revisit whenever an Exemplar problem reveals a concept gap.
- Class 12 Biology Formula Sheet: keep this open while attempting Exemplar problems so formula recall is one glance away.
- Class 12 Biology NCERT Book PDF: the main textbook; cross-check derivations when an Exemplar problem references a textbook result.
- Class 12 Biology Handwritten Notes: notebook-style revision between Exemplar problem-solving sessions.
How to Use the Class 12 Biology NCERT Exemplar Solutions Most Effectively
5-STEP METHOD · CBSE TOPPER ROUTINE
How to Use the Exemplar Solutions - Class 12 Biology
- 1Read the chapter first. Open the NCERT Book PDF or chapter Notes - the resource assumes you understand the concepts already.
- 2Attempt each question on your own. Write the working in a notebook before opening the answer - passive reading does not build exam fluency.
- 3Compare your working to the resource. Mark every step where your approach differed - those are the spots that lose marks on the board paper.
- 4Flag questions taking over 7 minutes. These go on the re-attempt list for the final-week revision pass.
- 5Mark every question that took over 10 minutes. Those are the ones worth a third pass in the final week - Exemplar problems repeat ideas, so the slow ones today become quick ones a fortnight later.
- After each chapter's back-exercise: attempt the Exemplar problems on your own first, then compare your working against the Solutions.
- Within 2 months of NEET / AIIMS / CUET: work every SA and LA Exemplar problem of the high-weightage chapters. Use the Expert's Solution tab for the longer working.
- 1 month before the boards: revisit the marked-difficult Exemplar problems and re-verify against the Solutions.
- Skip in the final week: Exemplar Solutions are too long for night-before revision; switch to the Notes and Formula Sheet at that point.
Common Mistakes Class 12 Biology Students Make with NCERT Exemplar Solutions
- Confusing autosomal dominant vs autosomal recessive inheritance patterns: Chapter 4 students often misread a pedigree. The autosomal recessive pattern skips generations; autosomal dominant appears in every generation. Always tag the parents' phenotype before predicting the children's.
- Mixing up transcription and translation directions: Chapter 5 students reverse the 5' to 3' direction during the transcription step. mRNA is synthesised 5' to 3' using the template strand read 3' to 5'.
- Treating menstrual cycle phases as fixed dates: Chapter 2 questions ask for the hormonal change at a phase, not a date. Ovulation triggers a LH surge around day 14 of a 28-day cycle, but the question is about which hormone peaks, not which calendar day.
- Forgetting that Hardy-Weinberg requires five conditions: Chapter 6 students often list only no mutation and random mating. The full set includes no migration, no genetic drift, no selection, and large population size. CBSE deducts 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 formation of new species. Read the verb carefully before answering.
- Ignoring 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 penalises the mismatch.
- Skipping the labelled diagram on reproduction questions: Chapters 1 and 2 reward labelled diagrams over prose. A complete 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 Exemplar Solutions usage
- 68% of students rated Chapter 5 Molecular Basis of Inheritance as the highest-effort chapter, ahead of 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 ~28% of students despite carrying 5 marks). Toppers flagged this as a high-ROI reclaim because the in-situ vs ex-situ table is memorisable in under an hour.
- Toppers reported that working 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, mostly 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, with Chapters 4, 5, 9, 10 eating the most time per question.
Also Check: Related Class 12 Biology 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 Exemplar Solutions
- Attempt every Exemplar problem on your own first; the Solutions are a verification tool, not a teaching tool.
- When the Expert's Solution differs from your method, write both in your notebook side by side; the comparison locks in the alternative approach.
- For NEET / AIIMS / CUET, focus the SA and LA Exemplar Solutions on the high-weightage chapters first; the MCQ and MCQ-II sections come second.
- The Exemplar Solutions cover every problem in the Exemplar Book PDF; cross-link by chapter when you find a Solution unclear and need the textbook's worked example for context.
Class 12 Biology Exemplar Solutions FAQs
Ques. Where can I download the Class 12 Biology Exemplar Solutions PDF?
Ans. Every chapter-wise Class 12 Biology Exemplar Solutions PDF is downloadable directly from the index above, from Chapter 1 Sexual Reproduction in Flowering Plants through Chapter 13 Biodiversity and Conservation. A combined all-chapters PDF is also linked. Both Normal and HD resolutions are free.
Ques. Is this Class 12 Biology Exemplar Solutions aligned with the 2026-27 NCERT?
Ans. Yes. Every chapter reflects the current 2026-27 syllabus. Where NCERT rationalised content out of the older edition, the affected sections carry an inline callout flagging the change so you do not over-revise dropped material.
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 tracks each chapter's mark share so you can plan your revision time around the high-yield chapters.
Ques. How are these Class 12 Biology Exemplar Solutions different from the other Class 12 Biology resources?
Ans. The Class 12 Biology Exemplar Solutions is best paired with the Exemplar Book PDF for the source problems and the Notes for the concept refresher. Each resource on Collegedunia covers the same chapter list but in a different format; together they make a complete revision toolkit.
Ques. Are these Class 12 Biology Exemplar Solutions files available in Hindi medium?
Ans. Yes. Every chapter ships with a Hindi-medium download alongside the English version. The Hindi files follow NCERT's own technical vocabulary (Jaiv Vigyan) so that students preparing in Hindi medium find the same terminology they have studied in.
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. The six-chapter shortlist in the Where to Start section above together delivers 39 of 70 board marks.
Ques. How should I structure my Class 12 Biology preparation?
Ans. Build chapter by chapter, prioritising the high-weightage units. Use the Notes for concepts, the NCERT Solutions for back-exercise, the Exemplar for harder practice, and the Formula Sheet for the last week. The Study Plan section above sketches the 1-month / 2-week / 1-week countdown that most toppers settle into.
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