The Class 12 Biology NCERT Exemplar Solutions (2026-27 syllabus) give you worked-out answers to every MCQ, MCQ-II, VSA, SA, and LA problem in the NCERT Exemplar Problems book. Each chapter comes as a free PDF you can download.
Class 12 Biology NCERT Exemplar Solutions PDF Download
Here is every chapter of the 2026-27 Class 12 Biology NCERT Exemplar. Each row links the worked-solutions PDF for that chapter.
Each answer shows the step-by-step working you need for the harder Exemplar problems in NEET, AIIMS, and CUET.
- 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
Subject experts write every solution in this Collegedunia Class 12 Biology NCERT Exemplar Solutions set. Each one is mapped to the 2026-27 NCERT Exemplar and matches the NEET, AIIMS, and CUET working patterns that examiners reward.
How will Collegedunia's Class 12 Biology NCERT Exemplar Solutions Help You?
The Exemplar Solutions take you past the NCERT back-exercise into the deeper ideas that competitive exams test. Use them after the back-exercise and before mock tests. They take you from board-level comfort to 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 book gets a worked solution.
- 2026-27 NCERT Exemplar match: every solution matches the latest Exemplar print. Dropped content carries an inline callout.
- Two-tab Solution format: a short Solution shows the least working a board examiner expects. A longer Expert's Solution shows the fuller, competitive-exam reasoning.
- Other methods shown: when a problem has more than one approach, you get both, so you can pick the one that suits you.
- Easy cross-links: jump from any Exemplar Solution to the same chapter's Notes, NCERT Solutions, Formula Sheet, or Handwritten Notes in one click.
- Checked by subject experts: every solution is checked against the official Exemplar key and the latest NEET, AIIMS, and 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)
Here is how the 13 Exemplar chapters fit into the CBSE units below. The Exemplar Solutions cover every problem in the source Exemplar book, 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
NCERT trimmed the 2026-27 Class 12 Biology syllabus to lower the load for CBSE Boards and NEET. The topics below are officially out of the 2026-27 question paper, so skip them while revising.
| Chapter | Deleted Topics (2026-27) |
|---|---|
| Reproduction in Organisms (formerly Ch 1) | Full chapter removed in the 2026-27 update. 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) | Some sub-parts of microbes in industrial production are removed. Sewage treatment stays. |
| Biodiversity and Conservation (Ch 15) | Ecosystem services valuation and biodiversity-hotspots details are removed. |
| Environmental Issues (formerly Ch 16) | Full chapter removed. Air pollution, water pollution, and the greenhouse effect are dropped. |
| Biotechnology - Principles (Ch 11) | Some details on restriction enzyme types (sub-parts) are removed. |
| Human Reproduction (Ch 2) | Details on government reproductive-health schemes are removed. |
The chapter 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 most of the CBSE 2026 Class 12 Biology paper and 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 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 steps next to the CBSE board-style structured answer.
EXEMPLAR SOLUTIONS · CLASS 12 BIOLOGY
Class 12 Biology - Exam Weightage
Class 12 Biology is worth about 160 marks combined across CBSE Boards and NEET UG. That is the single largest scoring block for medical-entrance students.
Class 12 Biology Weightage Snapshot (CBSE 2026 Theory Paper)
Put more Exemplar effort into the heavier chapters. Genetics and Evolution gives 20 marks of the 70-mark paper. Most of the harder Exemplar problems sit here too.
| 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 each section's 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 Section 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. Labelled-diagram questions and process-explanation questions sit here.
- Section D (2 case-study questions of 4 marks each): You apply genetics, ecology, or biotechnology to a passage. Sub-parts test how you read it.
- Section E (3 questions of 5 marks each): Long answer. Full-system answers (reproductive system, photosynthesis pathway, DNA replication) anchor this section.
The 70-mark theory paper plus the 30-mark internal assessment (practical, project, viva) makes the 100-mark scheme. Internal assessment marks go up as your lab notebook and viva prep improve. The theory paper is where your chapter-wise NCERT prep really shows.
Where to Start with Class 12 Biology NCERT Exemplar Solutions
Start with the six high-weightage chapters where worked Exemplar practice gives the biggest competitive-exam mark boost. Together these six chapters cover 39 of 70 board marks:
- Chapter 5, Molecular Basis of Inheritance (8 marks): the highest-weightage chapter. Transcription, translation, and DNA replication diagrams appear in almost every board paper.
- Chapter 4, Principles of Inheritance and Variation (7 marks): Mendel's laws, pedigree analysis, and sex determination come back year on 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 pairs 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.
Class 12 Biology NCERT Exemplar Solutions PDF Formats
- HD print-ready PDF: high-resolution layout for the printed problem-and-solution booklet.
- Standard download PDF: smaller file size for phone reading.
- Hindi-medium Exemplar Solutions PDF: chapter-wise Hindi versions that use NCERT's own terms (Jaiv Vigyan).
- Combined all-chapters PDF: one file with every chapter's Exemplar Solutions back to back.
- MCQ key plus worked solutions: the MCQ key sits at the front of each chapter's PDF for a quick check, with the full worked solutions after it.
How Class 12 Biology NCERT Exemplar Solutions Pair with the Other Resources
- Class 12 Biology Exemplar Book PDF: the source problem set. Open it next to the Solutions for the question text.
- Class 12 Biology NCERT Solutions: the back-exercise worked answers. Finish these first, before you open the Exemplar.
- Class 12 Biology Notes: the concept layer. Go back to it whenever an Exemplar problem shows a gap.
- Class 12 Biology Formula Sheet: keep it open while you try Exemplar problems, so formulas stay one glance away.
- Class 12 Biology NCERT Book PDF: the main textbook. Check derivations here when an Exemplar problem uses 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. This resource assumes you already know the concepts.
- 2Try each question on your own. Write the working in a notebook before you open the answer. Just reading answers does not build exam speed.
- 3Compare your working to the resource. Mark every step where your method differed. Those are the spots that lose marks in 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. These deserve a third pass in the final week. Exemplar problems repeat ideas, so today's slow ones become quick ones two weeks later.
- After each chapter's back-exercise: try the Exemplar problems on your own first, then compare your working with the Solutions.
- Within 2 months of NEET, AIIMS, or CUET: work every SA and LA Exemplar problem in the high-weightage chapters. Use the Expert's Solution tab for the longer working.
- 1 month before the boards: go back to the problems you marked as hard and check them against the Solutions again.
- Skip in the final week: Exemplar Solutions are too long for night-before revision. Switch to the Notes and Formula Sheet then.
Common Mistakes Class 12 Biology Students Make with NCERT Exemplar Solutions
- Mixing up autosomal dominant and autosomal recessive patterns: Chapter 4 students often misread a pedigree. Autosomal recessive skips generations. Autosomal dominant 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' from the template strand, which is 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 sets off an LH surge around day 14 of a 28-day cycle. But the question is 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 adds 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 call a zoo 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 Feedback: 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. About 28% of students skip it, even though it carries 5 marks. Toppers call it an easy reclaim, since you can learn the in-situ vs ex-situ table in under an hour.
- Toppers said 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 score. Most of it 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 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
- Try every Exemplar problem on your own first. The Solutions are for checking your work, not for learning the topic.
- When the Expert's Solution differs from your method, write both in your notebook side by side. This helps the other method stick.
- For NEET, AIIMS, and CUET, do the SA and LA Exemplar Solutions of the high-weightage chapters first. Do the MCQ and MCQ-II parts next.
- The Exemplar Solutions cover every problem in the Exemplar Book PDF. When a Solution feels unclear, open the same chapter's textbook worked example for context.
Class 12 Biology Exemplar Solutions FAQs
Ques. Where can I download the Class 12 Biology Exemplar Solutions PDF?
Ans. You can download every chapter's Class 12 Biology Exemplar Solutions PDF straight from the index above. It runs from Chapter 1 Sexual Reproduction in Flowering Plants to Chapter 13 Biodiversity and Conservation. A combined all-chapters PDF is also linked. Both Normal and HD versions are free.
Ques. Is this Class 12 Biology Exemplar Solutions aligned with the 2026-27 NCERT?
Ans. Yes. Every chapter follows the current 2026-27 syllabus. Where NCERT dropped content from the older edition, those sections carry an inline callout, so you do not over-revise removed 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 shows each chapter's mark share, so you can plan your revision time around the high-scoring chapters.
Ques. How are these Class 12 Biology Exemplar Solutions different from the other Class 12 Biology resources?
Ans. Pair the Class 12 Biology Exemplar Solutions with the Exemplar Book PDF for the source problems and the Notes for a concept refresher. Each Collegedunia resource covers the same chapter list 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 comes with a Hindi-medium download next to the English version. The Hindi files use NCERT's own terms (Jaiv Vigyan), so Hindi-medium students see the same words they have studied.
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 and 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 gives 39 of 70 board marks together.
Ques. How should I structure my Class 12 Biology preparation?
Ans. Build chapter by chapter, and put the high-weightage units first. Use the Notes for concepts, the NCERT Solutions for the back-exercise, the Exemplar for harder practice, and the Formula Sheet for the last week. The Study Plan section above shows the 1-month, 2-week, and 1-week countdown that most toppers use.
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