CBSE Class 12 Biology Syllabus 2025-26 Exam
CBSE Class 12 Biology Syllabus 2025 is very important for students to prepare effectively for the upcoming board exams. The Biology 12th syllabus is also a key part of entrance exams like NEET. Many questions in NEET come directly from the Biology topics covered in Class 12th and 11th. That's why knowing the complete list of topics included in the Biology 12th syllabus can help you focus on the right ones and plan your studies better.
CBSE 12 Biology Syllabus covers important units like Reproduction, Genetics and Evolution, Biology and Human Welfare, Biotechnology, and Ecology. These Biology topics for class 12 are a mix of theory and practical. Keep reading to learn about the detailed CBSE Class 12 Biology Syllabus, along with the distribution of marks, and tips to prepare effectively.
Check Out: CBSE Class 12 Books
CBSE Class 12 Biology Syllabus 2025-26 Exam
CBSE Class 12 Biology Syllabus 2025 gives you a clear idea of what you need to study throughout the year. It helps you learn about many interesting topics, like how our body works, how traits are passed from parents to children, and how diseases spread, among others. Biology helps you think deeply and understand the science behind life.
Syllabus of Biology Class 12 is divided into five main units. These include Reproduction, Genetics and Evolution, Biology and Human Welfare, Biotechnology, and Ecology. Each unit has its own weightage and importance. Studying them deeply, one by one, will help you cover the full CBSE 12 Biology syllabus in a systematic and stress-free way.
Chapter-Wise Weightage of Biology CBSE Class 12 Syllabus
Biology CBSE Class 12 syllabus is divided into five units. Each unit covers different types of topics and carries a fixed number of marks in the theory exam, as explained here:
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The first unit of the Biology 12th syllabus is Reproduction, which carries 14 marks. It includes how plants and humans reproduce and related topics.
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The second unit is Genetics and Evolution. It is one of the most important units and has the highest weightage of 18 marks. It explains how traits are passed from one generation to another and how living things have evolved over time.
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The CBSE Class 12 Biology syllabus's third unit is Biology and Human Welfare. Questions from this unit carry around 12 marks. It is based on topics like health, diseases, and how biology helps in improving human life.
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The Biotechnology and Its Applications is the fourth unit, which carries 10 marks, where you will learn about modern technology used in biology, like genetic modification and DNA tools.
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The last unit of the CBSE 12 Biology syllabus is Ecology and Environment. Questions asked from it carry around 16 marks. This unit focuses on how living things interact with nature and how we can protect the environment.
In total, all five units in the Biology CBSE Class 12 Syllabus carry a total of 70 marks in the theory section of the board exam.
Check Out: Class 12 Question Banks
Detailed Syllabus of Biology Class 12
Now that you've learned about the unit-wise weightage, let's also check what topics each unit covers. These are the Biology topics for Class 12 that you need to study very deeply throughout the year. Moreover, by going through the detailed syllabus of Biology Class 12 you can prepare well for your board exams and avoid missing any important chapter.
Each unit covers important concepts that are commonly asked in both board and entrance exams. So, by understanding what’s included in every part of the CBSE Class 12 Biology syllabus, you can make a robust study plan that will give you more time to study the concepts you may find tough.
Biology 12th Syllabus: Reproduction (Unit 6)
This unit in the CBSE Biology Class 12 syllabus explains how living things reproduce new life. It covers both asexual and sexual reproduction in plants and animals. You will also learn about the human reproductive system and different methods of birth control, etc.
The Reproduction unit of the Biology 12th syllabus is very important, especially if you want to study biology or medicine after passing 12th. Check out the chapters and important biology topics for Class 12 from this unit here:
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Biology 12th Syllabus: Reproduction Unit 6 |
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Chapter Name |
Key Topics Covered |
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Reproduction in Organisms |
Asexual and sexual reproduction, life cycles of plants and animals |
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Sexual Reproduction in Flowering Plants |
Structure of flower, male and female gametophytes, pollination (types and examples), pollen-pistil interaction, double fertilization, seed and fruit formation, apomixis, parthenocarpy, polyembryony |
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Human Reproduction |
Male and female reproductive systems, spermatogenesis and oogenesis, menstrual cycle, fertilisation, embryo development up to blastocyst stage, implantation, pregnancy, placenta, parturition, lactation |
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Reproductive Health |
Importance of reproductive health, STDs, birth control methods, MTP, amniocentesis, infertility, assisted reproductive technologies like IVF, ZIFT, GIFT |
CBSE Class 12 Biology Syllabus: Genetics and Evolution (Unit 7)
Genetics and Evolution is one of the most important units of the CBSE Class 12 Biology Syllabus 2025-26 exam. It explains how traits are passed from parents to children (genetics) and how living things have changed over time (evolution).
The following biology topics for Class 12 covered in the Genetics and Evolution unit are very important for your board exams as well as for medical entrance exams like NEET.
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CBSE Class 12 Biology Syllabus: Genetics and Evolution (Unit 7) |
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Chapter Name |
Key Topics Covered |
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Principles of Inheritance and Variation |
Mendel’s laws of inheritance, monohybrid and dihybrid crosses, incomplete dominance, co-dominance, multiple alleles, blood group inheritance, sex determination, genetic disorders like haemophilia, thalassemia, Down’s syndrome, Turner’s and Klinefelter’s syndromes |
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Molecular Basis of Inheritance |
DNA and RNA structure, DNA replication, transcription and translation, genetic code, gene regulation (lac operon), genome projects, DNA fingerprinting |
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Evolution |
Origin of life, Darwin’s theory, natural selection, genetic drift, types of evolution, Hardy-Weinberg principle, human evolution, and evidence of evolution from fossils and anatomy |
Check Out: Class 12 Textbooks
CBSE 12 Biology Syllabus: Biology and Human Welfare (Unit 8)
The Biology and Human Welfare unit tells about how biology is related to our health and everyday life. It explains how diseases spread, how we can protect ourselves, and how biology helps in farming and food production. This unit of the CBSE 12 Biology syllabus is important for understanding real-life uses of biology.
Furthermore, in this unit, you will learn about common human diseases, vaccines, drug abuse, and also how useful microbes are in making food, treating waste, and protecting crops. Find the detailed list of chapters and biology topics for Class 12 included in this unit here:
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CBSE 12 Biology Syllabus: Biology and Human Welfare (Unit 8) |
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Chapter Name |
Key Topics Covered |
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Human Health and Diseases |
Types of diseases: Infectious and non-infectious; pathogens and parasites causing malaria, dengue, typhoid, pneumonia, etc.; immunity and vaccines; cancer, HIV/AIDS; adolescent issues like drug and alcohol abuse |
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Strategies for Enhancement in Food Production |
Plant breeding, crop improvement, hybridization, genetic modification, animal husbandry, fish farming |
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Microbes in Human Welfare |
Role of microbes in food processing (like curd, cheese), industrial production, sewage treatment, biogas generation, antibiotics, biopesticides, and biofertilizers |
Biology CBSE Class 12 Syllabus: Biotechnology and Its Applications (Unit 9)
The Biotechnology and Its Applications unit makes you aware of the exciting world of biotechnology, where science and technology come together to solve real-life problems. It explains how scientists change the genes of plants, animals, and even humans to improve health, food production, and industry.
This unit of the Biology CBSE Class 12 syllabus is very useful if you want to explore careers in medicine, pharmacy, genetics, or research. From making insulin in the lab to creating pest-resistant crops, this unit covers many useful applications of biotechnology. Check out the chapters and important biology topics for Class 12 covered in this unit below:
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Biology CBSE Class 12 Syllabus: Biotechnology and Its Applications (Unit 9) |
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Chapter Name |
Key Topics Covered |
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Biotechnology – Principles and Processes |
Basics of genetic engineering, recombinant DNA technology, cloning, tools, and steps of genetic modification |
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Biotechnology and Its Applications |
Use of biotechnology in medicine (insulin, vaccines, gene therapy), agriculture (Bt crops, GMOs), transgenic animals, stem cell technology, biosafety, biopiracy, and patents |
CBSE Biology Class 12 Syllabus: Ecology and Environment (Unit 10)
In the Ecology and Environment unit, you’ll learn how plants, animals, and people are all connected to nature, and why it’s important to take care of the environment we live in. Nowadays, where pollution and climate change are increasing problems, this unit of the Biology CBSE Class 12 syllabus helps you understand why ecology and conservation are vital.
You will learn about how populations grow, how energy moves in an ecosystem, and how we can protect animals, plants, and natural places like forests and rivers. Here are the chapters and biology topics for Class 12 included in this unit:
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CBSE Biology Class 12 Syllabus: Ecology and Environment (Unit 10) |
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Chapter Name |
Key Topics Covered |
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Organisms and Populations |
Population interactions – mutualism, competition, predation, parasitism; population growth, birth and death rates, age distribution |
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Ecosystem |
Ecosystem components, productivity, decomposition, energy flow, ecological pyramids (pyramids of number, biomass, and energy) |
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Biodiversity and Conservation |
Concept and importance of biodiversity, loss of biodiversity, endangered species, hotspots, Red Data Book, national parks, wildlife sanctuaries, biosphere reserves, and conservation methods |
Important Biology Topics for Class 12
Some chapters from the Biology CBSE Class 12 syllabus are asked more frequently in board exams and other entrance tests. So, if you're aiming for high marks, giving extra time to such topics while studying can greatly help you. Check some of the most important biology topics for Class 12 that you should not skip here:
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Important Biology Topics for Class 12 |
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Sexual Reproduction in Flowering Plants |
Pollination, fertilization, seed and fruit formation, life cycle stages |
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Human Reproduction |
Male and female systems, gametogenesis, menstrual cycle, fertilization, pregnancy |
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Mendel’s Laws of Inheritance |
Dominant/recessive traits, monohybrid/dihybrid crosses, linkage, mutation |
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Molecular Basis of Inheritance |
DNA and RNA structure, transcription, translation, and important experiments |
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Evolution and Origin of Life |
Darwin’s theory, Hardy-Weinberg principle, types of evolution, and genetic drift |
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Biotechnology and Its Applications |
Recombinant DNA technology, PCR, gene therapy, GMOs |
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Human Health and Diseases |
Infectious diseases, symptoms, prevention, immunity, vaccines |
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Ecosystem |
Energy flow, food chains, pyramids, pollution, forest, and wildlife conservation |
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Microbes in Human Welfare |
Role of microbes in food, medicine, biogas, biofertilisers, sewage treatment |
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Biodiversity and Conservation |
Importance of biodiversity, threats, national parks, conservation strategies |
Check Out: Class 12 Sample Papers
Why Knowing the Syllabus of Biology Class 12 Is Important
Knowing the syllabus of Biology Class 12 helps you stay on the right path while studying. CBSE keeps making minor changes in the syllabus almost every year; while some topics are added, some are removed. Following the latest syllabus prevents you from wasting time on chapters that are deleted.
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When you go through the latest CBSE Class 12 Biology Syllabus 2025, you know exactly what to study.
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You can give more time to high-weightage important chapters like Genetics, Biotechnology, and Ecology, which are also vital for NEET.
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It also helps you understand which experiments are needed for practical exams and how marks are distributed.
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Most importantly, it saves your time and makes your board and other entrance exam preparation easy to manage.
Tips to Study CBSE Class 12 Biology Syllabus for Board 2025-26 Exam
CBSE Class 12 Biology syllabus has only five units, but each one covers many important concepts. Since you also have other subjects to study, it's better to start your Biology preparation early. The good thing is that most Biology questions are theory-based, so with regular revision, you can score really well. Here are some tips that will help you study smart and score better marks:
Manage Your Time Well:
Make a daily study routine for Biology. Spend more time on topics that feel tough. Don’t forget to practice diagrams because they are very important in the exam.
Focus on Understanding, Not Just Learning:
Try to understand what you’re studying. Use simple tricks like short notes, flowcharts, or drawings to remember topics like the life cycle, DNA processes, and immunity.
Solve Past Years' Papers:
Solve sample papers and last year’s question papers. This will help you know the kind of questions asked in the board exam. Use a timer while solving so you can understand the time limit and improve your speed accordingly.
You can also solve questions from CBSE Class 12 Last 3 Years (2022 - 2024) Solved Papers for Biology and PCM to check your preparation.
Use Good Additional Books Along with NCERT:
While NCERT is a must, you can also study from additional Class 12th Books that explain each topic in an easy to understand way and can be used as a resource for revision.
One such book is CBSE Question BankClass 12 Biology by PW. It includes chapter-wise and topic-wise solved questions for the upcoming exams, with 50% competency-based questions to match the latest exam pattern.
Follow the Latest Curriculum:
Make sure you are studying as per the updated CBSE Class 12 Biology Syllabus and exam pattern. This will help you focus only on the topics that matter and avoid wasting time on chapters that are not part of the exam.
Read More: Toughest and Easiest Chapters in CBSE Class 12 Biology
CBSE Class 12 Biology Syllabus 2025-26 Exam FAQs
Q.1. What is the CBSE Class 12 Biology Syllabus?
Ans. CBSE Class 12 Biology syllabus includes all the chapters and topics you need to study for the board exam. It is divided into five units: Reproduction, Genetics and Evolution, Biology and Human Welfare, Biotechnology and Its Applications, and Ecology and Environment.
Q.2. How many chapters are there in the Biology 12th syllabus?
Ans. There are a total of 16 chapters in Class 12 Biology, divided across the five main units.
Q.3. How many times do I need to study Biology topics for Class 12 for NEET?
Ans. For NEET, it is best to read the NCERT Biology topics at least 3 to 4 times. For tough chapters, you may need to revise them 7 to 8 times. Make the goal to understand concepts deeply.
Q.4. Is the Biology CBSE Class 12 syllabus tough?
Ans. CBSE Class 12 Biology syllabus is easy to manage if studied properly. It is mostly theory-based and becomes easy if you understand the concepts and do revisions daily.
Q.5. Are there any changes in the CBSE 12 Biology syllabus for NEET?
Ans. Yes, there are some changes in the Class 12 Biology syllabus for NEET. These topics have been removed from the NEET syllabus: Reproduction in Organisms, Strategies for Enhancement in Food Production, Succession, and Environmental Issues.
