CBSE Syllabus Biology Class 12 2026 | Free PDF for 2025-26 Exams

When someone asks students about Biology, many excitedly say, “I love Biology, I live Biology!” And why not? Biology is not just a subject; it’s the study of life itself! For Class 12 students, it plays a crucial role in shaping their future, especially for those aiming for NEET and other competitive exams.

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The CBSE Class 12 Biology Syllabus 2025-26 is designed to deepen students' understanding of life sciences while preparing them for board exams and beyond. Covering fascinating topics like Genetics, Evolution, Biotechnology, and Ecology, the syllabus ensures a perfect balance of theory, practicals, and application-based learning.

To ace the subject, students rely on the NCERT Class 12 Biology book PDF, which simplifies complex concepts and aligns perfectly with the CBSE syllabus. But just reading isn’t enough—smart preparation with NCERT solutions, exemplar problems, and previous years’ questions can make all the difference. So, if you’re ready to dive into the world of Biology and score big, let’s explore the detailed CBSE syllabus for 2025-26 and the best ways to prepare!

Like the Class 12 Biology Syllabus, students can also go through the Class 12 Physics syllabus & Class 12 Chemistry syllabus to plan their exams accordingly. Students can create a combined routine & strategies for these exams to perform well and manage their time.

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CBSE Class 12 Biology Syllabus: Unit-wise Breakdown

Biology is one of the most important subjects for Class 12 students, especially for those preparing for CBSE board exams and NEET. To help students plan their studies effectively, the CBSE Class 12 Biology Syllabus 2025-26 is divided into different units, covering key topics like Reproduction, Genetics, Evolution, Biotechnology, and Ecology.

A structured approach to studying these units will not only help in scoring well but also build a strong foundation for competitive exams. Below is the unit-wise breakdown of the syllabus for the 2025-26 academic session.

Unit-VI Reproduction

Chapter 2: Sexual Reproduction in Flowering Plants

Flower structure; development of male and female gametophytes; pollination - types, agencies and examples; out breeding devices; pollen-pistil interaction; double fertilization; post-fertilization events - development of endosperm and embryo, development of seed and formation of fruit; special modes- apomixis, parthenocarpy, polyembryony; Significance of seed dispersal and fruit formation.

Chapter 3: Human Reproduction

Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis-spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development up to blastocyst formation, implantation; pregnancy and placenta formation (elementary idea); parturition (elementary idea); lactation (elementary idea).

Chapter 4: Reproductive Health

Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs); birth control - need and methods, contraception and medical termination of pregnancy (MTP); amniocentesis; infertility and assisted reproductive technologies - IVF, ZIFT, GIFT (Elementary idea for general awareness).

Unit-VII Genetics and Evolution

Chapter 5: Principles of Inheritance and Variation

Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete dominance, co-dominance, multiple alleles and inheritance of blood groups, pleiotropy; elementary idea of polygenic inheritance; chromosome theory of inheritance; chromosomes and genes; Sex determination - in humans, birds and honey bees; linkage and crossing over; sex-linked inheritance - haemophilia, colour blindness; Mendelian disorders in humans - thalassemia; chromosomal disorders in humans; Down's syndrome, Turner's and Klinefelter's syndromes.

Chapter 6: Molecular Basis of Inheritance

Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA packaging; DNA replication; Central Dogma; transcription, genetic code, translation; gene expression and regulation - lac operon; Genome, Human and rice genome projects; DNA fingerprinting.

Chapter 7: Evolution

Origin of life; biological evolution and evidence for biological evolution (palaeontology, comparative anatomy, embryology and molecular evidence); Darwin's contribution, to modern synthetic theory of evolution; mechanism of evolution - variation (mutation and recombination) and natural selection with examples, types of natural selection; Gene flow and genetic drift; Hardy - Weinberg's principle; adaptive radiation; human evolution.

Unit-VIII Biology and Human Welfare

Chapter 8: Human Health and Diseases

Pathogens; parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm) and their control; Basic concepts of immunology - vaccines; cancer, HIV and AIDS; Adolescence - drug and alcohol abuse.

Chapter 10: Microbes in Human Welfare

Microbes in food processing, industrial production, sewage treatment, energy generation and microbes as bio-control agents and bio-fertilizers. Antibiotics; production and judicioususe.

Unit-IX Biotechnology and its Applications

Chapter 11: Biotechnology - Principles and Processes

Genetic Engineering (Recombinant DNA Technology).

Chapter 12: Biotechnology and its Applications

Application of biotechnology in health and agriculture: Human insulin and vaccine production, stem cell technology, gene therapy; genetically modified organisms - Bt crops; transgenic animals; biosafety issues, biopiracy and patents.

Unit-X Ecology and Environment

Chapter 13: Organisms and Populations

Population interactions - mutualism, competition, predation, parasitism; population attributes - growth, birth rate and death rate, age distribution. (Topics excluded: Organism and its Environment, Major Abiotic Factors, Responses to Abiotic Factors, Adaptations)

Chapter 14: Ecosystem

Ecosystems: Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy (Topics excluded: Ecological Succession and Nutrient Cycles).

Chapter 15: Biodiversity and its Conservation

Biodiversity- concept, patterns, importance; loss of biodiversity; biodiversity conservation; hotspots, endangered organisms, extinction, Red Data Book, Sacred Groves, biosphere reserves, national parks, wildlife, sanctuaries and Ramsar sites.

List of Experiments

1. Prepare a temporary mount to observe pollen germination.
2. Study the plant population density by quadrat method.
3. Study the plant population frequency by quadrat method.
4. Prepare a temporary mount of onion root tip to study mitosis.
5. Isolate DNA from available plant material such as spinach, green pea seeds, papaya, etc.

List of Practicals

1. Study of flowers adapted to pollination by different agencies (wind, insects).
2. Identification of T.S of morula or blastula of frog (Model).
3. Study of Mendelian inheritance pattern using beads/seeds of different sizes/textures.
4. Preparation of pedigree charts of genetic traits such as rolling of the tongue, and colour blindness.
5. Study of emasculation, tagging and bagging by trying out an exercise on controlled pollination.
6. Identify common disease-causing organisms like Ascaris (model)and learn some common symptoms of the disease that they cause.
7. Comment upon the morphological adaptations of plants found in xerophytic conditions.

Items for Identification/ familiarity with the apparatus (All experiments) 

Beaker, flask, Petri plates, soil from different sites - sandy, clayey, loamy,small potted plants, aluminium foil, paintbrush, test tubes, starch solution, iodine, ice cubes, Bunsen burner/spirit lamp/water bath, large flowers, Maize inflorescence, model of developmental stages highlighting morula and blastula of frog, beads/seeds of different shapes/size/texture Ascaris, Cactus/Opuntia(model).

Spotting

1. Flowers adapted to pollination by different agencies (wind, insects, birds).
2. Pollen germination on stigma through a permanent slide or scanning electron micrograph.
3. Identification of stages of gamete development, i.e. T.S. of testis and T.S. of ovary through permanent slides (from grasshopper/ mice).
4. Meiosis in onion bud cells or grasshopper testis through permanent slides.
5. T.S. of the blastula through permanent slides (Mammalian).
6. Mendelian inheritance uses seeds of different colours/sizes of any plant.
7. Prepared pedigree charts of any one of the genetic traits such as rolling of tongue, blood groups, ear lobes, widow's peak and colour blindness.
8. Controlled pollination - emasculation, tagging and bagging.
9. Common disease-causing organisms like Ascaris, Entamoeba, Plasmodium, and any fungus-causing ringworm through permanent slides, models or virtual images. Comment on symptoms of diseases that they cause.
10. Models specimen showing symbolic association in root modules of leguminous plants, Cuscuta on the host, lichens.
11. Flashcard models showing examples of homologous and analogous organs.

Why to Download Class XII Biology Syllabus 2025-26

Biology is a crucial subject for Class 12 students, especially for those preparing for the CBSE board exams and NEET. To score well, students must focus on the right topics, practicals, and exam patterns—and the best way to do this is by referring to the official CBSE Class 12 Biology Syllabus 2025-26.

Downloading the latest syllabus gives you a clear roadmap for your preparation, ensuring that you study effectively without wasting time on unnecessary topics. Below, we explore in detail why downloading the syllabus is essential.

Stay Updated with the Latest CBSE Syllabus

Every year, CBSE revises the syllabus, making modifications to align with the latest educational standards. Some topics may be added, removed, or revised, so relying on an outdated syllabus could lead to confusion and wasted effort.

By downloading the official CBSE Class 12 Biology Syllabus 2025-26, you ensure that:

• You focus only on relevant topics that will be asked in the exam.
• You don’t study extra chapters that have been removed.
• You follow the latest guidelines for both theory and practical exams.

Understand the Unit-Wise Weightage

Not all topics carry equal marks in the CBSE exam. Some units are more important and carry higher weight than others.

By having the syllabus, you can:

• Identify high-scoring chapters and give them more time.
• Allocate study time based on marks distribution.
• Plan revision smartly to cover important topics first.

For example, Genetics and Evolution and Biotechnology usually carry higher marks than other units. Without knowing this, students may end up spending too much time on less important topics.

Align Your Preparation with NCERT Books

CBSE Biology board exam questions are directly based on NCERT textbooks. Downloading the syllabus helps you map each topic to the NCERT book, making your study approach more efficient.

With the syllabus, you can:

• Match each topic in the NCERT Biology Class 12 PDF with the syllabus.
• Focus on NCERT exercises and exemplar problems that are relevant.
• Avoid wasting time on topics that are not part of the syllabus.

Tip: After studying a topic, cross-check it with the syllabus to ensure full coverage.

Focus on Practical and Project Work

Apart from theory, practical exams and project work carry significant marks in CBSE Biology. Many students ignore this part and lose easy marks.

Downloading the syllabus helps you:

• Know which experiments and projects are mandatory.
• Prepare practical records as per CBSE guidelines.
• Understand the marking scheme for practical exams.

Common Class 12 Biology Practicals include:

• Study of mitosis in onion root tip cells.
• Identification of common diseases through permanent slides.
• Biochemical tests for carbohydrates, proteins, and fats.
• Effect of temperature and pH on enzyme activity.

Tip: Ensure your practical file is complete and neat, as it is graded internally!

Organised and Effective Exam Preparation

Without a proper syllabus, your study plan may lack direction. A well-structured syllabus helps you:

• Create a realistic study timetable.
• Focus on important concepts first.
• Avoid wasting time on irrelevant topics.
• Plan smart revision before exams.

Tip: Use the syllabus to divide your time efficiently. For example:

• First 3 months: Cover all chapters with NCERT & notes.
• Next 2 months: Revise important concepts + solve past papers.
• Last month: Focus on weak areas + mock tests.

Helps in NEET and Competitive Exam Preparation

For NEET aspirants, Class 12 Biology plays a vital role since over 50% of NEET Biology questions are based on Class 12 NCERT topics.

Downloading the syllabus ensures that:

• You don’t miss any important NEET topics covered in CBSE.
• You practice exemplar and NCERT-based MCQs.
• You focus on Genetics, Biotechnology, and Ecology, which are crucial for NEET.

Tip: Solve NCERT-based MCQs daily and revise from the syllabus to ensure full coverage.

Download Once, Use Anytime

Having the CBSE Class 12 Biology Syllabus PDF saved on your device is highly beneficial because:

• You can access it anytime, anywhere—no need to search online again and again.
• You can print a hard copy and keep it with your study materials.
• You can highlight important topics and tick off completed ones.

Tip: Keep the printed syllabus on your study table as a quick reference guide.

Downloading the CBSE Class 12 Biology Syllabus 2025-26 is essential for every student. It keeps your preparation structured, focused, and effective, ensuring you don’t waste time on unnecessary topics.

How to Complete Class 12 Biology Syllabus 2025-26 on Time?

Class 12 Biology is a vast subject, and completing the syllabus on time is essential for board exams and NEET preparation. Many students struggle with time management, leading to last-minute stress and incomplete revision. However, with a smart study plan and the right approach, you can easily complete the CBSE Class 12 Biology Syllabus 2025-26 promptly.

Here’s a step-by-step guide to help you study efficiently and stay on track.

Know Your Syllabus Well

The first step in completing your syllabus on time is to understand what to study. Download the CBSE Class 12 Biology Syllabus 2025-26 and go through all the topics.

Unit-wise Breakdown for Time Management:

• High-weightage topics – Genetics, Biotechnology, and Human Physiology
• Moderate-weightage topics – Ecology and Reproduction
• Easy & scoring topics – Microbes in Human Welfare, Biodiversity, and Evolution

Tip: Prioritise high-weightage topics first and then move to the rest.

Make a Study Plan and Stick to It

A well-planned timetable helps in structured learning. Instead of random studying, divide your syllabus into manageable sections and set weekly targets.

Ideal Study Plan (6-Month Schedule):

• Month 1 & 2 – Complete Reproduction + Genetics & Evolution
• Month 3 & 4 – Cover Biotechnology + Human Welfare + Ecology
• Month 5 – Revise the full syllabus + Solve NCERT-based questions
• Month 6 – Mock tests + Last-minute revision

Tip: Allocate 2-3 hours per day for Biology and solve questions daily.

Focus on NCERT – Your Best Friend

For CBSE exams and NEET, NCERT Class 12 Biology is the most important book. 90% of questions in board exams are directly from NCERT.

How to Study NCERT Effectively?

• Read each chapter line by line—don’t skip anything.
• Highlight important points, terms, and definitions.
• Solve NCERT back exercises & exemplar questions.
• Practice NCERT-based diagrams—these are important in exams.

Tip: Make flashcards or sticky notes for difficult terms and revise them regularly.

Use Short Notes for Quick Revision

Instead of reading long chapters before the exam, prepare concise notes while studying.

What to Include in Notes?

• Definitions & important terms
• Flowcharts for biological processes
• Diagrams with labelling
• Important formulas (e.g., DNA replication, genetic ratios)

Tip: Revise your notes every Sunday to strengthen your memory.

Master Diagrams & Labeling

Biology is a visual subject, and diagrams help in scoring full marks. Many questions are based on diagram-based explanations.

Important Diagrams to Practice:

• Human reproductive system (Male & Female)
• DNA structure & replication
• Mendelian inheritance (Monohybrid & Dihybrid cross)
• Biogeochemical cycles

Tip: Practice drawing diagrams every day for at least 15 minutes.

Solve Previous Year Papers & Sample Papers

Practising past papers helps in understanding the exam pattern and boosting confidence.

How to Use Previous Year Papers Effectively?

• Solve at least 5 years’ past papers.
• Time yourself to improve speed and accuracy.
• Analyse mistakes and revise weak topics.
• Solve sample papers & mock tests every week.

Tip: Treat previous papers as real exams and attempt them seriously.

Revise Regularly – The Key to Retention

Without regular revision, it’s easy to forget concepts. Plan multiple revisions before the exams.

Suggested Revision Plan:

• 1st Revision – After completing each unit (Weekly)
• 2nd Revision – Mid-term (After 3 months)
• Final Revision – 1 month before exams (Full syllabus)

Tip: Use mind maps, flowcharts, and mnemonics for quick recall.

Manage Your Time Wisely

Avoid procrastination and distractions (social media, TV, etc.). Stick to your study plan and take short breaks to stay focused.

Time Management Tips:

• Follow the Pomodoro technique (Study 50 mins, break 10 mins).
• Avoid cramming—focus on understanding concepts.
• Study in a quiet place with no distractions.

Tip: Stay consistent—small daily efforts lead to big results.

By following the syllabus, you can:

• Study the right topics from NCERT.
• Allocate time based on mark weightage.
• Prepare effectively for both theory and practical exams.
• Improve your NEET and board exam performance.

Download the syllabus now and start preparing smartly!