CBSE Class Twelve Board Exam Biology 2026
CBSE Class Twelve Board Exam Biology
CBSE Class 12 Biology notes as per the latest CBSE Class 12 syllabus has been provided in this article. Students can make use of these CBSE Class 12 notes which consist of important concepts, theories, NCERT Solutions PDFs and important questions for their CBSE Class 12 Board exam preparation.
CBSE Class 12 Biology Notes & Syllabus
CBSE Class 12 Biology syllabus consists of 13 chapters classified under 6 units. The new CBSE Class 12 Biology syllabus for the AY 2022-23 is tabulated below.
| Unit. No | Unit | Chapters | Marks |
|---|---|---|---|
| VI | Reproduction | Sexual Reproduction in Flowering Plants Human Reproduction | 16 |
| VII | Genetics and Evolutions | Principles of Inheritance and Variation Molecular Basis of Inheritance Evolution | 20 |
| VIII | Biology and Human Welfare | 12 | |
| IX | Biotechnology and its Applications | 12 | |
| X | Ecology and Environment | 10 | |
| Total | 70 | ||
Class 12 Biology Notes for Chapter 2: Sexual Reproduction in Flowering Plants
This chapter includes various topics related to the sexual reproduction in flowering plants. Important topics covered in Sexual Reproduction in flowering Plants Chapter are-
- Flower structure
- Vegetative propagation in plants
- Pollination
- Gemmule formation
- Double fertilization
- Parthenocarpy
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read, NCERT Solutions for Sexual Reproduction in Flowering Plants
Class 12 Biology Notes for Chapter 3: Human Reproduction
This chapter introduced the concept of Reproductive System of Humans along with related topics like- Fertilization, stem cells etc. Important topics covered in Human Reproduction Chapter are-
- Male and Female Reproductive system
- Menstrual cycle
- Female Hormones
- Implantation
- Lactation
- Parturition
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Oogenesis | Follicle Stimulating Hormone | Placenta Definition |
| Difference Between Sperm And Ovum | Blastocyst | Sex Hormones And Reproductive Functions |
| Length Of Epididymis | Gametogenesis Spermatogenesis Oogenesis | Fallopian Tube |
| Ovum | Scrotum | Uterus |
| Vagina | Contraception | NCERT Solutions for Human Reproduction |
Class 12 Biology Notes for Chapter 4: Reproductive Health
This chapter can be considered as an extensive study related to the previous chapter. It als deals with the concept of Infertility and other health issues related to the reproductive helath. Here are the imoprotant topics from this chapter-
- Sexually Transmitted Diseases (STIs)
- Birth control
- Medical termination of pregnancy
- Infant Mortality Rate
- Syphili
- Amniocentesis
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Maternal mortality rate | Gestational Diabetes | NCERT Solutions for Reproductive Health |
Class 12 Biology Notes for Chapter 5: Principles of Inheritance and Variation
In this chapter the students will learn about the Principles of Inheritance and Variation along with idaes of Linkage and crossing over, Colour blindness, Thalassemia, Hemophilia. Here are the important topics from this chapter-
- Mendelian Inheritance
- Incomplete Dominance
- Pleiotropy
- Chromosomal Theory of Inheritance
- Chromosomes and Genes
- Down’s Syndrome
Expected number of questions: 2 to 3 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Genetics | Genetic Disorders | Blood Group Test |
| Chromosomal Theory of Inheritance | Allele Definition | Inheritance Definition |
| Chromosomal Abnormalities | Genotype Definition | Difference Between Gene And Allele |
| Difference Between Incomplete Dominance And Codominance | Mendelian Genetics | Difference Between Gene And Dna |
| Difference Between Monohybrid And Dihybrid | Genotype And Phenotype Difference | Autosomes And Allosomes |
| Behavioural Genetics | Non Mendelian Inheritance | Phenotype Definition |
| Monohybrid Cross | Dihybrid Cross | Genetic History Of Family |
| Principles Of Genetics | Co Dominance And Multiple Alleles | NCERT Solutions for Principles of Inheritance and Variation |
Class 12 Biology Notes for Chapter 6: Molecular Basis of Inheritance
This chapter can be considered as an extensive part of the previous chapters. It includes topics like- DNA packaging, DNA replication, Genetic code, Genome, DNA. Here are the important topics from this chapter-
- Structure of DNA
- Structure of RNA
- Transcription
- Lac operon
- Genome and Genomics
- DNA fingerprinting
Expected number of questions: 2 to 3 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Human genome project | Bioinformatics | Translation |
| Difference Between Dna And Rna | Difference Between Nucleotide And Nucleoside | What Is Translation In Biology |
| VNTR | Gene Regulation | Difference Between Euchromatin And Heterochromatin |
| DNA Genetic Material | Translation Protein Synthesis | Difference Between Prokaryotic And Eukaryotic Transcription |
| DNA Polymerases | Model Organism | NCERT Solutions for Molecular Basis of Inheritance |
Class 12 Biology Notes for Chapter 7: Evolution
This chapter is all about Evolution and it deals with the related topics like Lamarckism, Palaeontology, Origin of Life etc. Here are the important topics from this chapter-
- Origin and Evolution of Man
- Mechanism of Evolution
- Charles darwin theory
- Homo erectus
- Genetic drift
- Embryology
- Gene flow
Expected number of questions: 2 to 3 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Malthusian Theory of Population | Difference Between Homologous and Analogous Structures | Types of Natural Selection |
| Adaptive Radiation | Comparative Anatomy | Biogenetic Law |
| Allopatric And Sympatric Speciation | Industrial Melanism | NCERT Solutions for Evolution |
Class 12 Biology Notes for Chapter 8: Human Health and Diseases
In this chapter the ideas of various diseases are described with their causes. This chapter includes- Pathogens, Malaria, Dengue, Filariasis, etc. Here are the important topics related to this chapter-
- Disease
- Immunity
- Cancer
- AIDS
- Metastasis
- Alcohol and Drug Abuse
- Typhoid
Expected number of questions: 1 to 3 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Pneumonia | Common cold | Amoebiasis |
| Ringworm | Vaccines | Infectious Diseases |
| Osteoarthritis | Plague | Diphtheria |
| Tetanus | Lung Cancer | Antigen And Immunology |
| Rheumatoid Arthritis | Polyarthritis | Blood Cancer |
| Apoptosis | Colon Cancer | Ascariasis |
| Skin Cancer Symptoms | Retrovirus | Vector Borne Diseases |
| Plasmodium Life Cycle | Difference Between Antigen And Antibody | Hepatitis |
| Difference Between Aids And Hiv | Difference Between Vaccination And Immunization | Difference Between T Cells And B Cells |
| Human Bacterial Diseases | Difference Between Humoral and Cell-Mediated Immunity | Adolescence and Drug Abuse |
| Nipah Symptoms | Primary Ciliary Dyskinesia | Taeniasis |
| Throat Cancer Symptoms | T Cells | Interferon |
| Lymphocyte | Toxoplasmosis Lifecycle | Class 12 Biology Chapter 8 Human Health and Diseases |
Class 12 Biology Notes for Chapter 10: Microbes in Human Welfare
In this chapter the ideas about microbes in human welfare are explained here that includes the ideas of Ganga action plan, Leprosy, vitamin b 12 deficiency etc. Here are the important topics from this chapter-
- Sewage Treatment
- Antibiotics
- Fertilizers
- Microbiology
- Microbes in production of biogas
Expected number of questions: 1 to 3 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Biogas | Biology and Human Welfare | Bio Control Agents |
| Microbes As Biofertilizers | Microbes In Industrial Products | NCERT Solutions for Microbes in Human Welfare |
Class 12 Biology Notes for Chapter 11: Biotechnology Principles and Processes
This chapter introduced the core ideas of Biotechnology. It includes related topics like the applications of biotechnologies, Extinction, Endengered Species and pcr etc. Here are the important topics from this chapter-
- Genetic Engineering
- Recombinant DNA Technology
- Biotechnology and its applications
- DNA Cloning
- Restriction Enzymes
Expected number of questions: 1 to 5 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Cloning Vector | Insertional Inactivation | Bacterial Transformation |
| Antimicrobial Resistance | Competent Cells | E Coli |
| NCERT Solutions for Chapter 12 Biotechnology and Its Applications | Bioprocessing | NCERT Solutions for Biotechnology – Principles and Processes |
Class 12 Biology Notes for Chapter 12: Biotechnology and its Applications
This chapter can be considered as an extensive study related to the previous chapter. In this chapter related topics like Plasmid Definition, GEAC, etc. Important topics covered in Biotechnology and Its Applications Chapter are:
- Biotechnology In Agriculture
- Applications of Enzymes
- Transgenic Animals
- Genetically modified organisms
- Human insulin
- RNA Interference
Expected number of questions: 1 to 5 questions of 1-5 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Elisa Technique | Biotechnology Mcqs | NCERT Solutions for Biotechnology and its Application |
Class 12 Biology Notes for Chapter 13: Organisms and Population
This chapter includes a detailed study on the topic- Organisms and Populations, along with the concept of studying population by quadrat method. Important topics covered in Organisms and Population Chapter are-
- Population
- Population interactions
- Mutualism
- Predation
- Parasitism
- Commensalism
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read, NCERT Solutions for Organisms and Population
Class 12 Biology Notes for Chapter 14: Ecosystem
This chapter deals with a very important topic- Ecosystem. In this chapter the related topics like Photosynthetically active radiation, Phosphorus Cycle, Abiotic Factors, etc. Important topics covered in this chapter are-
- Importance of Ecosystem
- Carbon Cycle
- Biomass
- Energy flow in ecosystem
- Aquatic Ecosystem
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Biotic Factors | Grazing Food Chain | What Is Decomposition |
| Productivity in Ecosystem | Humification | Mineralisation |
| Detritus Food Chain (DFC) | Pyramid of Biomass | Carnivores Herbivores |
| Hydrarch Succession | Tundra Ecosystem | Ecotone |
| What Is A Natural Ecosystem | Terrestrial Ecosystem | NCERT Solutions for Ecosystem |
Class 12 Biology Notes for Chapter 15: Biodiversity and Conservation
This chapter deals with the related topics with the previous chapter. In this chapter, related topics like Biodiversity conservation, Hotspots, Endemic Species are explained. Important topics covered in Biodiversity and Conservation Chapter are-
- Biosphere reserves
- Loss of biodiversity
- National parks
- Ramsar sites
- Red Data Book
- Sanctuaries
- Wildlife
- Mass extinctions
Expected number of questions: 1 to 3 questions of 1-3 marks
Also Read,
| Other Important Links From This Chapter | ||
|---|---|---|
| Cryopreservation | Keystone Species | Flagship Species |
| Kt Extinction | Biodiversity And Conservation MCQ | NCERT Solution for Biodiversity and Conservation |
Class 12 Biology Practicals
CBSE Class 12 Biology practicals has a weightage of 30 marks in total and the test shall be conducted for a duration of 3 hours.
The distribution of marks for the Class 12 Biology practicals is tabulated below.
| Evaluation Scheme for Practicals | Marks |
|---|---|
| Major Experiment | 5 |
| Minor Experiment | 4 |
| Slide Preparation | 5 |
| Spotting | 7 |
| Record | 4 |
| Project | 5 |
| Total | 30 |
Popular Reference books & Additional Resources
Students can also make use of these additional resources for Class 12 Biology Notes where all the important concepts, topics, theories and handwritten notes are available.
- Truman’s Class 12 Elementary Biology
Also Check,
| Class 11 & 12 PCMB Study Guides and Syllabus | ||
|---|---|---|
| NCERT Class 11 Biology Book | Comparison Topics in Biology | NCERT Solutions for Class 12 Physics |
| Class 12 Chemistry Practicals | Choice based questions in physics | Class 11 Syllabus |
| Topics for Comparison in Physics | Class 12 Physics Book PDF | Topics with relation in physics |
| Important Derivations in Physics | NCERT Solutions for Class 12 Chemistry | Important Physics Constants and Units |
| Physics MCQs | Biology MCQs | NCERT Solutions for Class 12 Biology |
| NCERT Solutions for Class 12 English | NCERT Solutions for Class 12 Maths | Class 12 Chemistry Notes |
| NCERT Class 12 Biology Book | Class 12 Chemistry notes | Class 12 Maths Notes |
| Class 12 PCMB Notes | Formulas in Physics | NCERT Class 12 Maths Book |
| NCERT Class 12 Textbooks | NCERT Solutions for Class 11 Maths | NCERT Solutions for Class 11 Physics |
| NCERT Solutions for Class 11 Chemistry | NCERT Solutions for Class 11 Biology | NCERT Solutions for Class 11 English |
| NCERT Class 11 Chemistry Book | NCERT Class 11 Physics Book | SI units in Physics |
| Class 11 Notes | Important Maths Formulas | Important Chemistry Formulas |
| Class 11 PCMB Syllabus | Chemistry Study Notes | NCERT Solutions Class 6 to 12 |
| Periodic Table in Chemistry | Important Chemical Reactions | Comparison topics in Chemistry |
| Comparison Topics in Maths | CBSE Class 12 Chemistry syllabus | Important Named Reactions |
CBSE Class 12 Biology Notes FAQ
Ques. Is it necessary to memorize all the scientific names mentioned in the syllabus?
Ans. While it's helpful to know the scientific names, focus more on understanding the concepts and processes behind them. Memorization can aid in recall during exams, but understanding the principles is more crucial for application-based questions.
Ques. How can I improve my understanding of complex topics like molecular genetics and biotechnology?
Ans. Break down complex topics into smaller, manageable chunks. Use visual aids such as diagrams, flowcharts, and animations to grasp difficult concepts. Discuss and clarify doubts with teachers, classmates, or online forums. Practice CBSE Biology previous year paper, solving problems, and answering questions related to these topics regularly.
Ques. What are the key topics covered in the CBSE Class 12 Biology syllabus?
Ans. The syllabus covers a wide range of topics including sexual reproduction in flowering plants, human reproduction, principles of inheritance and variation, molecular basis of inheritance, evolution, human health and diseases, biotechnology principles and processes, organisms and populations, biodiversity and conservation, and more.
Ques. Are NCERT textbooks sufficient for Class 12 Biology preparation?
Ans. NCERT textbooks are the foundation for your preparation. They cover the entire syllabus in a clear and concise manner. However, it's also beneficial to refer to other supplementary books and resources for deeper understanding and practice.
Ques. How important are practicals in Class 12 Biology?
Ans. Practical exams carry a weightage of 30 marks in total. It's essential to practice and understand the experiments, slide preparations, and record keeping as per the CBSE guidelines. A good performance in practical exams can significantly boost your overall score.
