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By Shailendra Singh
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Updated on 12 Jun 2025, 13:39 IST
NCERT Solutions for Class 12 Biology are your all-in-one guide to understanding this important subject in your final school year. These PDF files provide easy, step-by-step answers to every question in your NCERT textbook. Even tough topics in biology become simple to learn and remember with these solutions.
The Class 12 Biology syllabus includes interesting topics like molecular biology, ecology, genetics, reproduction, evolution, and more. These topics help build a strong base for competitive exams like NEET and other entrance tests. Each chapter is arranged in a way that takes you from basic ideas to advanced concepts, helping you learn smoothly.
If you're looking for the NCERT Class 12 Biology textbook PDF or quick answers to textbook questions, having the right materials can really help your preparation. The chapter list includes everything you need for board exams and future studies in biology.
Our Class 12 Biology NCERT solutions PDFs are made to help you understand even the hardest questions. The language is simple and clear, and every answer is explained step by step. We’ve also included extra questions and diagrams that are important for exams.
By using these solutions regularly, you'll feel more confident with biology and gain a deeper understanding of the subject that will help you in school and beyond.
This chapter explains how flowering plants reproduce. It covers pollination (how pollen reaches the flower), fertilization (joining of male and female cells), and seed formation. It also explains different types of pollination and parts of a flower.
This chapter talks about how humans reproduce. You will learn about male and female reproductive organs, how sperm and eggs are formed, and the stages from pregnancy to childbirth.
This chapter focuses on staying healthy in terms of reproduction. It explains birth control methods, how to prevent sexually transmitted diseases (STDs), and medical termination of pregnancy (abortion). It also covers family planning.
Here, you’ll learn how traits (like eye color) are passed from parents to children. It introduces Mendel’s experiments, genetic disorders, dominant and recessive traits, and how differences appear in a population.
This chapter explains how genes work. It talks about DNA structure, how DNA copies itself, how proteins are made, and how RNA helps in this process. You'll also learn about the genetic code.
This chapter explains how living things have changed over time. It includes Darwin’s theory of natural selection and evidence like fossils and body structures that support the idea of evolution.
This chapter is about diseases that affect humans. It covers how diseases spread, how to prevent and treat them, and the role of vaccines and immunity. It also talks about healthy habits.
This chapter shows how tiny living things (microbes) are useful. It covers how microbes help make medicines, food, and enzymes, and how they are used in farming and cleaning waste.
This chapter introduces biotechnology. It explains how scientists change genes, use DNA technology, and create clones. It also covers the basic tools and steps used in genetic engineering.
This chapter shows how biotechnology helps in real life. It talks about genetically modified (GM) crops, gene therapy in medicine, and how industries use biotechnology to make products.
This chapter explains how living things interact with each other and their environment. It covers population growth, food chains, and how species live together in an ecosystem.
This chapter explains how ecosystems work. It talks about how energy flows through food chains, how nutrients like carbon and nitrogen cycle in nature, and the roles of plants, animals, and decomposers.
This chapter discusses why we need to protect different kinds of plants and animals. It explains the threats to biodiversity and how we can conserve nature using protected areas and laws.
| NCERT Solutions for Class 12 Biology Chapters | Chaptes PDF |
| NCERT Solutions for Class 12 Chapter 1 | Reproduction in Organisms |
| NCERT Solutions for Class 12 Chapter 2 | Sexual Reproduction in Flowering Plants |
| NCERT Solutions for Class 12 Chapter 3 | Human Reproduction |
| NCERT Solutions for Class 12 Chapter 4 | Reproductive Health |
| NCERT Solutions for Class 12 Chapter 5 | Principles of Inheritance and Variation |
| NCERT Solutions for Class 12 Chapter 6 | Molecular Basis of Inheritance |
| NCERT Solutions for Class 12 Chapter 7 | Evolution |
| NCERT Solutions for Class 12 Chapter 8 | Human Health and Diseases |
| NCERT Solutions for Class 12 Chapter 9 | Strategies for Enhancement in Food Production |
| NCERT Solutions for Class 12 Chapter 10 | Microbes in Human Welfare |
| NCERT Solutions for Class 12 Chapter 11 | Biotechnology Principles and Processes |
| NCERT Solutions for Class 12 Chapter 12 | Biotechnology and its Application |
| NCERT Solutions for Class 12 Chapter 13 | Organisms and Populations |
| NCERT Solutions for Class 12 Chapter 14 | Ecosystem |
| NCERT Solutions for Class 12 Chapter 15 | Biodiversity and Conservation |
| NCERT Solutions for Class 12 Chapter 16 | Environmental Issues |
Reproduction in organisms is the biological process through which living beings give rise to new individuals. It ensures the continuation of species. Two main types exist: asexual and sexual reproduction. Asexual involves a single parent, leading to identical offspring, while sexual reproduction involves two parents and leads to genetic variation. It occurs in both unicellular and multicellular organisms.
Also, access the following resources for Class 12 Chapter 1 Reproduction in Organisms at Infinity Learn
Sexual reproduction in flowering plants involves the production of seeds through the fusion of male and female gametes. The male gamete (pollen) fertilizes the female gamete (ovule) within the ovary, forming a zygote. This results in the formation of a seed, which contains the embryo and nutritive tissues. The process ensures genetic diversity and the survival of plant species. Pollination, fertilization, and seed dispersal are key stages.
Also, access the following resources for Class 12 Chapter 2 Sexual Reproduction in Flowering Plants at Infinity Learn
Human reproduction is the process by which humans produce offspring. It involves the fusion of male and female gametes during sexual intercourse. Fertilization occurs in the fallopian tube, leading to the formation of a zygote. The zygote undergoes mitotic divisions, developing into an embryo, which implants in the uterus. After nine months, childbirth occurs. This process is essential for the continuation of the human species.
Also, access the following resources for Class 12 Chapter 3 Human Reproduction at Infinity Learn
Reproductive health refers to the overall well-being of the reproductive system in individuals. It encompasses safe sexual practices, family planning, access to healthcare, and prevention and treatment of reproductive disorders. Promoting reproductive health ensures the physical, mental, and social well-being of individuals and societies.
Also, access the following resources for Class 12 Chapter 4 Reproductive Health at Infinity Learn
Principles of inheritance and variation explain how traits are passed from one generation to another. Gregor Mendel’s laws of segregation and independent assortment form the basis. Genetic variation arises due to mutations, genetic recombination, and environmental factors, leading to diversity within populations.
Also, access the following resources for Class 12 Chapter 5 Principles of Inheritance and Variation at Infinity Learn
The molecular basis of inheritance elucidates how genetic information is stored, replicated, and transmitted. DNA is the genetic material, composed of nucleotides. Replication, transcription, and translation are essential processes involving enzymes and RNA molecules. Mutations can lead to genetic disorders.
Also, access the following resources for Class 12 Chapter 6 Molecular Basis of Inheritance at Infinity Learn
Evolution is the change in heritable traits within populations over successive generations. It’s driven by natural selection, genetic drift, and mutation. The theory of evolution by Charles Darwin explains how species adapt to their environment and gives rise to new species.
Also, access the following resources for Class 12 Chapter 7 Evolution at Infinity Learn
Human health and diseases explore factors influencing well-being and mechanisms underlying illnesses. Pathogens, genetic factors, lifestyle choices, and environmental conditions impact health. Understanding disease mechanisms aids in prevention and treatment.
Also, access the following resources for Class 12 Chapter 8 Human Health and Diseases at Infinity Learn
More food production is required as the world’s population grows ever-increasingly. Animal husbandry and plant breeding strategies play an important role in our efforts to increase food production. This chapter covers a variety of subtopics, including animal husbandry, plant breeding, single-cell proteins, and tissue culture.
Also, access the following resources for Class 12 Chapter 9 Strategies for Enhancement in Food Production at Infinity Learn
Microbes play vital roles in human welfare, including food fermentation, bioremediation, and producing medicines like antibiotics. They contribute to ecological balance and industrial processes.
Also, access the following resources for Class 12 Chapter 10 Microbes in Human Welfare at Infinity Learn
Biotechnology involves using biological systems for technological applications. Genetic engineering, gene cloning, and DNA manipulation are key processes. They have applications in medicine, agriculture, and industry.
Also, access the following resources for Class 12 Chapter 11 Biotechnology Principles and Processes at Infinity Learn
Biotechnology’s applications include producing transgenic organisms, recombinant proteins, and genetically modified crops. It revolutionizes medicine, agriculture, and environmental protection.
Also, access the following resources for Class 12 Chapter 12 Biotechnology and Its Application at Infinity Learn
Organisms and populations explore interactions within and among species. It studies population dynamics, ecological niches, and community structures, contributing to conservation efforts.
Also, access the following resources for Class 12 Chapter 13 Organisms and Populations at Infinity Learn
Ecosystems comprise living organisms and their physical environment. They include producers, consumers, and decomposers, with energy flowing through trophic levels. Ecosystems provide essential services and maintain ecological balance.
Also, access the following resources for Class 12 Chapter 14 Ecosystem at Infinity Learn
Biodiversity refers to the variety of life forms on Earth. Conservation aims to protect and sustain these forms for future generations. It involves preserving habitats, preventing species extinction, and promoting sustainable practices.
Also, access the following resources for Class 12 Chapter 15 Biodiversity and Conservation at Infinity Learn
Environmental issues address challenges such as pollution, deforestation, climate change, and resource depletion. Sustainable practices, policy changes, and global cooperation are crucial for a healthy planet.
Also, access the following resources for Class 12 Chapter 16 Environmental Issues at Infinity Learn
The CBSE (Central Board of Secondary Education) Class 12 marking scheme helps students understand how their answer sheets will be evaluated during the board exams. For the academic year 2025–26, CBSE continues to follow a competency-based assessment approach with more focus on concept clarity, real-life application, and critical thinking.
| Subject | Theory Marks | Practical/Project | Total Marks | Passing Marks (33%) |
| Physics | 70 | 30 | 100 | 33 |
| Chemistry | 70 | 30 | 100 | 33 |
| Biology | 70 | 30 | 100 | 33 |
| Mathematics | 80 | 20 (IA*) | 100 | 33 |
| English Core | 80 | 20 (ASL & IA*) | 100 | 33 |
| Accountancy | 80 | 20 (Project Work) | 100 | 33 |
| Business Studies | 80 | 20 (Project Work) | 100 | 33 |
| Economics | 80 | 20 (Project Work) | 100 | 33 |
| Computer Science (New) | 70 | 30 (Practical) | 100 | 33 |
| Informatics Practices | 70 | 30 (Practical) | 100 | 33 |
| Psychology | 70 | 30 (Practical) | 100 | 33 |
| Sociology, Geography etc. | 80 | 20 (Practical) | 100 | 33 |
CBSE Class 12 papers are now structured to include different types of questions to test various levels of learning:
| Type of Question | Approx. Weightage |
| Competency-Based Questions | 50% |
| Objective Type (MCQs, VSA, etc.) | 20% |
| Short & Long Answer Questions | 30% |
CBSE emphasizes continuous internal evaluation, including:
Marks are distributed clearly, and teachers submit them to CBSE as part of the final board results.
Solving Class 12 Biology NCERT solutions offers many advantages for students preparing for board exams and competitive tests like NEET. These solutions are created by experienced teachers and follow the CBSE syllabus closely, making them reliable and accurate. Here are the main benefits:
The ncert class 12 biology textbook covers a wide range of topics. Some chapters and topics are especially important for board exams and medical entrance tests. Here’s a list of key chapters and topics you should focus on:
| Unit/Chapter | Important Topics |
| Reproduction in Organisms | Modes of reproduction, asexual and sexual reproduction |
| Sexual Reproduction in Flowering Plants | Pre-fertilization events, double fertilization, inbreeding depression |
| Human Reproduction | Gametogenesis, fertilization, events of pregnancy |
| Reproductive Health | Birth control methods, STDs, infertility treatments |
| Principles of Inheritance and Variation | Mendel’s laws, post-Mendelian genetics, chromosomal disorders, pedigree analysis |
| Molecular Basis of Inheritance | DNA structure, replication, transcription, translation, genetic code, lac operon |
| Evolution | Homologous/analogous organs, adaptive radiation, Hardy-Weinberg principle |
| Human Health and Disease | Life cycle of Plasmodium, immunity, AIDS, drug abuse |
| Strategies for Enhancement in Food Prod. | Inbreeding/outbreeding, single-cell protein |
| Microbes in Human Welfare | Microbes in industry, sewage treatment, biogas production |
| Biotechnology: Principles & Processes | Restriction enzymes, cloning vectors, recombinant DNA technology |
| Biotechnology and Its Applications | Bt cotton, RNA interference, gene therapy, genetically engineered insulin |
| Organisms and Populations | Population interactions, ecological pyramids |
| Ecosystem | Structure, function, energy flow, nutrient cycling |
| Biodiversity and Conservation | Causes of biodiversity loss, conservation strategies |
| Environmental Issues | Air pollution, eutrophication, biomagnification |
Practicing questions from ncert solutions for class 12 biology helps you test your understanding and prepare for exams. Here are some sample practice questions based on the NCERT syllabus:
The academic team at Infinity Learn has meticulously crafted NCERT solutions for Class 12 Biology, intending them as reference material solely. Avoid copying these solutions. Instead, engage with the chapters, attempt questions independently, and consult your textbook if needed. If challenges persist, turning to the NCERT solutions for Class 12 Biology can be a helpful step.
Class 12 Biology is divided into two integral sections: zoology and botany. Each segment carries equal significance in the CBSE board examination. Comprehensive understanding across all chapters is advisable, with specific focus on key topics including Reproduction, Genetics, Human Welfare, Biotechnology, and Ecology, which warrant dedicated attention.
The questions found in NCERT textbooks serve as valuable tools to enhance comprehensive studying and achieve strong performance in exams. By actively engaging with NCERT Solutions Class 12 Biology, students can elevate their academic performance and strengthen their understanding of the subject, leading to a more solid grasp of the syllabus.
Since the NEET syllabus aligns with the NCERT, students aspiring for NEET should primarily focus on the NCERT Textbook. Yet, this alone isn't sufficient for comprehensive NEET preparation. Infinity Learn addresses this challenge by organizing live sessions, led by experienced subject experts. These sessions supplement learning with vital study materials and an interactive platform for students to clarify doubts and grasp complex concepts.