CBSE Class 12 Biology Notes For 2025 Board Exams Preparation

CBSE Class 12 Notes Biology:- CBSE Class 12 Biology Notes are designed to support students in their exam preparation. These notes enable students to make efficient use of their study time by providing well-organised and thoroughly researched information on all chapter topics. Each topic is presented clearly to help CBSE Class 12 students gain a solid understanding of the subject. With these notes, students can revise key concepts quickly, reducing stress, especially as the board exams approach. 

Prepared by faculty, the notes offer detailed coverage of each chapter, including important questions and answers likely to appear in the exam. Furthermore, they feature neatly labelled diagrams aligned with the NCERT textbook, making them ideal for both home assignments and exam preparation. Get the biology class 12 notes from the below article. 

Class 12 Biology Chapters

Biology is a fascinating and high-scoring subject, full of interesting facts and discoveries. It is an important subject in the science stream, and doing well in it can help students get into top medical institutions and other fields. However, just studying from the Class 12 textbook may not be enough to achieve a high score. Students need useful study materials like the CBSE Class 12 Biology Notes. To support them, we have put together notes for all chapters, which are also available for Classes 6 to 12, all in one place. Check out the Class 12 Biology Chapters below:- 

Biology Notes Class 12

Check out the biology notes for each chapter below:-

Chapter 1 – Sexual Reproduction in Flowering Plants

This chapter explains how flowering plants reproduce sexually. It covers the structure of flowers, the process of pollination (self and cross-pollination), and how seeds are formed through fertilisation. Key areas to focus on include the development of male and female gametes, the pollen-pistil interaction, and the process of seed and fruit development.

Read More: Class 12 Biology Chapter 1 Sexual Reproduction In Flowering Plants

Chapter 2 – Human Reproduction

This chapter explores the human reproductive system. It covers the structure of male and female reproductive organs, as well as the processes of spermatogenesis and oogenesis (formation of sperm and eggs). Important areas include fertilisation, implantation, and the development of the embryo. Understanding the hormonal control of reproduction and the menstrual cycle is crucial.

Read More: Class 12 Biology Chapter 2 Human Reproduction

Chapter 3 – Reproductive Health

This chapter focuses on the importance of maintaining good reproductive health. It discusses various contraceptive methods (like oral pills, IUDs, and sterilisation) and addresses reproductive health issues such as sexually transmitted diseases (STDs). Key topics to study include family planning, the use of contraceptives, and methods to treat infertility, such as IVF and GIFT.

Chapter 4 – Principles of Inheritance and Variation

This chapter introduces the basic principles of inheritance, based on Mendel’s laws. It explains monohybrid and dihybrid crosses, the chromosomal theory of inheritance, and sex determination. Focus on understanding Mendel’s experiments, genetic disorders, and the role of linked genes. Studying crossing over and inheritance patterns is also important.

Chapter 5 – Molecular Basis of Inheritance

This chapter covers how genetic information is passed from one generation to the next. Key areas include the structure of DNA and RNA, the process of DNA replication, and the central dogma (transcription and translation). Focus on understanding the genetic code, types of mutations, and the regulation of gene expression. The lac operon model is also important to study.

Chapter 6 – Evolution

This chapter explains the process of evolution and the evidence supporting it. It covers Darwin’s theory of natural selection, speciation, and the evolution of humans. Focus on the evidence of evolution from fossils, comparative anatomy, and molecular biology. Understanding concepts like genetic drift, gene flow, and adaptive radiation is important.

Chapter 7 – Human Health and Disease

This chapter discusses human health, the immune system, and diseases. It covers the types of immunity (innate and acquired), the structure of antibodies, and the role of vaccines. Focus on diseases such as AIDS, malaria, and cancer, and how they can be prevented and treated. The impact of lifestyle diseases like drug and alcohol addiction is also covered.

Check out: CBSE Question & Concept Bank Class 12 Biology 2024 - 2025

Chapter 8 – Microbes in Human Welfare

This chapter highlights the beneficial uses of microbes. It explains how microbes are used in industry (for alcohol and antibiotics), sewage treatment, and biogas production. Key areas include the role of microbes in agriculture, especially as bio fertilisers and biocontrol agents. Understanding their role in food processing and environmental management is also important.

Chapter 9 – Biotechnology: Principles and Processes

This chapter introduces biotechnology and its basic tools. It explains recombinant DNA technology, the use of restriction enzymes, and how gene cloning works. Important areas include the polymerase chain reaction (PCR), the use of vectors, and the role of bioreactors in large-scale production. Focus on understanding the steps involved in genetic modification.

Chapter 10 – Biotechnology and Its Applications

This chapter discusses how biotechnology is applied in medicine, agriculture, and the environment. It covers genetically modified organisms (GMOs), Bt cotton, and the use of biotechnology in gene therapy and medicine production (e.g. insulin). Ethical issues like biopiracy and the impact of GMOs on the environment are important areas to study.

Chapter 11 – Organisms and Populations

This chapter deals with how organisms interact with their environment and each other. It covers topics like population growth models (exponential and logistic), population interactions (e.g. predation, competition), and adaptations to different environments. Focus on understanding population density, age structure, and the role of carrying capacity in ecosystems.

Chapter 12 – Ecosystem

This chapter explains how ecosystems function. It covers the structure of ecosystems, the flow of energy through food chains, and the nutrient cycles (such as the carbon and nitrogen cycles). Key areas include the study of ecological pyramids, trophic levels, and the concept of productivity in ecosystems. Focus on understanding biogeochemical cycles and ecological succession.

Chapter 13 – Biodiversity and Conservation

This chapter emphasises the importance of biodiversity and how it can be conserved. It covers the types of biodiversity (genetic, species, and ecosystem diversity) and the threats it faces (e.g. habitat loss, pollution). Important areas include biodiversity hotspots, the causes of species extinction, and conservation strategies like national parks and seed banks. Understanding the role of in-situ and ex-situ conservation is crucial.

Check out: Class 12th Sample Papers

Benefits of Using Class 12 Biology Notes

Using Class 12 Biology Notes can be a game-changer for students preparing for their board exams. Here's an elaboration on the key benefits, along with a focus on important topics covered in these notes:

1. Simplified Explanation of Complex Concepts

Biology can often seem challenging with its detailed processes and scientific terms. Class 12 Biology Notes break down these difficult concepts into simple language, making it easier for students to understand. Topics like DNA replication, genetic inheritance, and evolutionary mechanisms are explained step by step, with the use of flowcharts and diagrams to clarify intricate biological processes.

2. Time-Saving Revision Material

Students often find themselves short on time during the exam preparation period. The Class 12 Biology Notes are designed to be concise, providing only the most relevant information. For example, essential areas such as sexual reproduction in plants, human reproduction, and biotechnology applications are summarised, so students can quickly review the main points without going back to the textbook for every detail. These notes are perfect for last-minute revisions.

3. Exam-Focused Preparation

The notes are specifically crafted to help students focus on the most important and exam-relevant topics. Key areas like Principles of Inheritance, Molecular Basis of Inheritance, and Human Health and Disease are often repeated in past exam papers. The notes include essential diagrams like those for the structure of DNA, processes like transcription and translation, and genetic crosses, which are crucial for scoring well.

4. Boosts Retention with Key Points and Diagrams

The visual aids, tables, and well-organised points in these notes are designed to enhance memory retention. For instance, in chapters like Microbes in Human Welfare and Ecosystem, where various microbes and their roles in processes like sewage treatment or biogas production need to be remembered, these notes help retain information through clear summaries and labelled diagrams.

5. Stress-Free Revision Before Exams

With a lot of content to cover in Class 12 Biology, revising everything can be overwhelming. These notes provide a stress-free way to revise as they condense the vast syllabus into key takeaways. Chapters like Evolution, Biodiversity and Conservation, and Biotechnology Principles are distilled into important points, allowing students to review the material quickly while feeling prepared. Also, consider using PW Class 12 Question Banks.

6. Faculty-Curated and Accurate Content

The Class 12 Biology Notes are created by faculty who have a deep understanding of the CBSE syllabus. These faculty ensure that the notes include accurate and up-to-date information. For instance, while studying Human Reproduction or Biotechnology Applications, students will find well-researched content on topics like hormonal regulation, gene cloning, and genetically modified organisms (GMOs).

8. Incorporates Past Exam Questions

Many of the notes are built around frequently asked questions in past board exams. This helps students practise answering the types of questions they are likely to face. Sections such as Human Health and Disease and Biotechnology Principles and Processes often feature diagram-based questions, which are included in the notes to aid understanding and recall.

9. Effective for Home Assignments and Self-Study

These notes are also useful for completing home assignments or preparing for school tests. Topics like Microbes in Human Welfare, Ecosystem, and Reproductive Health are simplified and summarised, making them handy for both self-study and quick references during homework or project work.

Read More: CBSE Class 12 Biology Sample Papers 2024-25 for Board exam

Class 12 Biology Notes FAQs

1. What are Class 12 Biology Notes?

Class 12 Biology Notes are concise summaries of each chapter in the CBSE Class 12 Biology syllabus. They are designed to help students understand and revise important concepts more effectively.

2. Are Class 12 Biology Notes enough for board exam preparation?

While the notes provide a solid foundation for revision, students should also refer to the NCERT textbook for detailed explanations and practise solving past question papers to score well in the exams.

3. Who prepares Class 12 Biology Notes?

The notes are typically prepared by faculty, teachers, or educators who understand the CBSE syllabus and the exam pattern.

4. What are the key benefits of using Biology Notes?

Biology Notes save time, simplify complex topics, highlight important areas for the exams, and offer well-structured, exam-focused content for quick revision.

5. Do the notes cover all chapters in the syllabus?

Yes, Class 12 Biology Notes cover all chapters in the CBSE Biology syllabus, from Sexual Reproduction in Flowering Plants to Biodiversity and Conservation.