CBSE Class 12 Biology Syllabus - Free PDF Download
CBSE Syllabus 2025-26 Class 12: The CBSE Class 12 Biology Syllabus for the examination year 2025-26 has been released by the Central Board of Secondary Education, CBSE. The board will hold the final examination at the end of the year following the annual assessment scheme, which has led to the release of the syllabus. The 2025-26 CBSE Class 12 Biology Board Exam will entirely be based on the most recent syllabus. Therefore, students must thoroughly understand the new CBSE syllabus to prepare for their annual exam properly.
The detailed CBSE Class 12 Biology Syllabus for 2025-26 is below.
Academic year:
CBSE Class 12 Biology Revised Syllabus
CBSE Class 12 Biology and their Unit wise marks distribution
CBSE Class 12 Biology Course Structure 2025-26 With Marking Scheme
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Syllabus
1: Reproduction [Revision]
CBSE Class 12 Biology Syllabus
1 Sexual Reproduction in Flowering Plants [Revision]
- Flower - a Fascinating Organ of Angiosperms
- Morphological Significance of the Flower
- Floral Whorls and Their Arrangement
- Male Reproductive Structures: Androecium
- Female Reproductive Structures: Gynoecium
- Pre-fertilisation in Flowering Plant: Structures and Events
- Structure and Development of Anther
- Structure of Anther and Pollen Chambers
- Anther Wall Layers and Their Functions
- Dehiscence of Anther
- Microsporogenesis
- Definition: Microsporogenesis
- Primary Sporogenous Tissue
- Meiotic Division
- Types of Pollen Tetrads
- Structure and Development of Male Gametophyte
- Structure of Pollen Grain
- Composition and Role of Sporopollenin
- Pollination and Pollen Germination
- Pollen Viability and Preservation
- Formation of Male Gametophyte
- Development of Male Gametes
- Pollen Products
- Structure and Development of Ovule
- Structure of Ovule
- Development of Ovule
- Megasporogenesis
- Definition: Megasporogenesis
- Process
- Development of Female Gametophyte or Embryo Sac
- Formation of Embryo Sac
- Cellular Organisation of Embryo Sac
- Pollination
- Definition: Pollination
- Self-pollination
- Autogamy
- Definition: Autogamy
- Introduction
- Autogamy
- Cross-pollination
- Geitonogamy
- Definition: Geitonogamy
- Introduction
- Xenogamy
- Outbreeding Devices
- Introduction
- Self-sterility (or Self-incompatibility)
- Dichogamy
- Herkogamy
- Heterostyly
- Unisexuality
- Geitonogamy
- Agents of Pollination
- Anemophily
- Definition: Anemophily
- Introduction
- Hydrophily
- Definition: Hydrophily
- Introduction
- Animal-Mediated Pollination (Zoophily)
- Pollen Pistil Interaction
- Artificial Hybridization or Artificial Fertilization
- Double Fertilization and Triple Fusion
- Definition: Fertilization
- Definition: Syngamy
- Definition: parthenogenesis
- Gamete Fusion in Sexual Reproduction
- External vs. Internal Fertilization
- Events in Sexual Reproduction
- Post-fertilization Events
- Definition: Post-fertilization Events
- Definition: Embryogenesis
- Developmental Stages After Fertilization
- Comparison Between Zygote and Zoospore
- Post-fertilization Events
- Endosperm
- Embryo
- Definition: Embryogenesis
- Introduction
- The Seed
- Definition: Seed
- Structure and Formation of the Seed
- Seed Variability and Adaptations
- Role and Importance of Seeds
- Apomixis
- Definition: Apomixis
- Types
- Mechanisms
- Significance
- Polyembryony
1 Reproduction in Organisms [Revision]
2 Human Reproduction [Revision]
- Human Reproduction
- Overview of The Male Reproductive System
- Overview of The Female Reproductive System
- Overview of Gametogenesis
- Structure of Sperms
- Introduction
- Head
- Neck
- Middle Piece
- Tail (Flagellum)
- Oogenesis
- Definition: Oogenesis
- Introduction
- Menstrual Cycle (Ovarian Cycle)
- Major Events of Menstrual Cycle
- Menstrual Hygiene
- Fertilization and Implantation
- Pregnancy and Embryonic Development
- Parturition and Lactation
3 Reproductive Health [Revision]
- Concept of Reproductive Health
- Introduction
- Problems
- Strategies
- Population Explosion and Birth Control
- Methods of Birth Control and Contraceptive Devices
- Natural Contraceptive Methods
- Artificial Contraceptive Methods
- Medical Termination of Pregnancy (MTP)
- Sexually Transmitted Diseases (STD) or Sexually Transmitted Infections (STI)
- Infertility
- Introduction
- Causes of Infertility
- Finding the Cause
- Finding a Remedy
- Coping with Infertility
- Assisted Reproductive Technology (ART)
- Amniocentesis
- Genetic Counselling
2: Genetics and Evolution [Revision]
CBSE Class 12 Biology Syllabus
4 Principles of Inheritance and Variation [Revision]
- Heredity and Variation
- Gregor Johann Mendel – Father of Genetics
- Mendel's Experiments Inheritance
- Monohybrid Cross
- Monohybrid Cross
- Representation of a Gene
- Punnett Square
- Back Cross and Test Cross
- Mendel's Law
- Exceptions to Mendel's Principles > Incomplete Dominance
- Exceptions to Mendel's Principles > Co-Dominance
- Dihybrid Cross
- Dihybrid Cross
- Reasons for Mendel’s Success
- Reciprocal Cross
- Chromosomal Theory of Inheritance
- Linkage and Recombination
- Polygenic Inheritance
- Exceptions to Mendel's Principles > Pleiotropy
- Sex Determination
- Mutations
- Pedigree Analysis
- Human Genetic Disorders
- Mendelian Disorders in Humans
5 Molecular Basis of Inheritance [Revision]
- Deoxyribonucleic Acid (DNA)
- Structure of Polynucleotide Chain
- Packaging of DNA Helix
- Search for Genetic Material
- Griffith’s Experiment
- Avery, McCarty and MacLeod’s Experiment
- The Hershey-Chase Experiment
- Properties of Genetic Material
- The RNA World
- DNA Replication
- Conservative Replication
- Dispersive Replication
- Semi-Conservative Replication
- Meselson and Stahl’s Experiment
- Enzymes used in DNA Replication
- Mechanism of DNA Replication
- Central Dogma
- Reverse Transcription (Teminism)
- Protein Synthesis
- Transcription Unit and the Gene
- Process of Transcription in Bacteria
- Process of Transcription in Eukaryotes
- Translation
- Genetic Code
- Characterestic of the Genetic Code
- tRNA – the Adapter Molecule
- Mutations and Genetic Code
- Regulation of Gene Expression
- Human Genome Project
- DNA Fingerprinting
6 Evolution [Revision]
- Origin and Evolution of Universe and Earth
- Theories of Origin of Life
- Origin of life
- Theories of origin of life
- Big Bang Theory
- Theory of Panspermia
- Theory of Spontaneous Generation or Abiogenesis
- Theory of Biogenesis
- Theory of Chemical Origin
- Urey and Miller's experiment
- Evolution of Life Forms - a Theory
- Theories of Biological Evolution
- Modern Synthetic Theory of Evolution
Modern Synthetic Theory of Evolution
- Genetic variations
- Natural selection
- Isolation
- Modern Synthetic Theory of Evolution
- Adaptive Radiation
- Organic Evolution
- Hardy Weinberg’s Principle
- Brief Account of Evolution
- Human Evolution
- Micro and Macro Evolution
- Evolution Stages
- Gene Flow and Genetic Drift
- Evolution
3: Biology and Human Welfare [Revision]
CBSE Class 12 Biology Syllabus
7 Human Health and Diseases [Revision]
- Common Diseases in Human Beings
- Immunity
- Types of Immunity > Innate Immunity
- Vaccination and Immunization
- Vaccination
- Immunization
- Allergies (Hypersensitivity)
- Introduction of Drugs and Alcohol Abuse
- Types and Effects of Psychoactive Drugs
- Adolescence - Drug and Alcohol Abuse
- Addiction and dependence
- Effects of drugs and alcohol
- Prevention and control
- Adolescence - Drug and Alcohol Abuse
- Infectious and Non Infectious Disease
- Maintaining Good Health, Yoga, Excercise
- Introduction of Human Health and Diseases
8 Microbes in Human Welfare [Revision]
- Microbes in Household Products
- Microbes in Industries
- Microbes in Sewage Treatment
- Microbes in Production of Biogas
- methanogens, biogas plant
- Microbes as Biocontrol Agents
- Microbes as Biofertilizers
- Energy Generation
- Production and Judicious Use
- Microbes in Human Welfare
Microbes in human welfare
- Microbes in food preparation
- Dosa, Dhokla and Idli
- Microbes as the Source of Food
- Dairy Products
8 Strategies for Enhancement in Food Production [Revision]
- Introduction of Strategies for Enhancement in Food Production
- Plant Breeding
Plant breeding
- Hybridization and its technique
Steps of Hybridization technique
Indian Hybrid Crops - Mutation Breeding
-Plant Breeding for Developing a Resistance to Insect Pest
- Hybridization and its technique
- Strategies for Enhancement in Food Production (Questions)
4: Biotechnology [Revision]
CBSE Class 12 Biology Syllabus
9 Biotechnology - Principles and Processes [Revision]
- Principles of Biotechnology
- Tools of Recombinant DNA Technology
- Cloning Vectors
- Cloning Vector
- Features that are required to facilitate cloning into a vector
(i) Origin of replication (ori)
(ii) Selectable marker
(iii) Cloning sites
⇒ Two processes for selection of recombinants over non-recombinants
(A) Inactivation of antibiotic resistance
(B) In presence of chromogenic substrate
(iv) Vectors for cloning genes in plants and animals
- Competent Host (For Transformation with Recombinant DNA)
- Competent Host (For Transformation with Recombinant DNA)
- Other methods of gene transfer
1) Microinjection
2) Gene gun/Biolistics
3) Disarmed Pathogen Vectors
- Cloning Vectors
- Processes of Recombinant DNA Technology
- Isolation of the Genetic Material (DNA)
- Cutting of DNA at Specific Locations
- Amplification of Gene of Interest using PCR
- Insertion of Recombinant DNA into the Host Cell/Organism
- Obtaining the Foreign Gene Product
- Downstream Processing
10 Biotechnology and Its Application [Revision]
- Introduction of Biotechnology and Its Application
- Applications of Biotechnology in Health and Medicine
- Transgenic Animals
- Ethical Issues
- Bio Piracy and Patents
- GEAC (Genetic Engineering Approval Committee)
- Biopiracy
- Patents
- Cyber Crime
- Software Piracy
- Hacking
- Cracking
- Biosafety Issues
- Vaccine safety testing
- Chemical safety testing
- Study of disease
5: Ecology [Revision]
CBSE Class 12 Biology Syllabus
4 Environmental Issues [Revision]
- Controlling Vehicular Air Pollution: a Case Study of Delhi
- Effects of Domestic Sewage and Industrial Effluents on Water
- Solid Wastes
- Municipal solid wastes
⇒ Steps that can be taken by us to reduce the non-biodegradable waste
(i) Burning of the waste
(ii) Sanitary landfills - Hospital Waste
- Electronic waste (e-waste)
- Incineration
- Recycling
- Case Study of Remedy for Plastic Waste
- Municipal solid wastes
- Radioactive Wastes
- Greenhouse Effect and Climate Change
- Greenhouse effect
- Global warming
- Effects of global warming
- Prevention of global warming
- Ozone Layer Depletion
- Ozone Depletion in the Stratosphere
- Ozone Layer Depletion
- causes and prevention (to be covered theoretically, no reactions are required)
- Formation of ozone:- relevant equations
- Function in the atmosphere.
- Destruction of the ozone layer:- chemicals responsible for this to be named but reactions not required.
- Ozone Depletion in the Stratosphere
- Degradation by Improper Resource Utilisation and Maintenance
- Soil erosion and desertification
- Waterlogging and soil salinity
- Radioactive Waste Management and E-waste
- Environmental Issues
11 Organisms and Populations [Revision]
- Introduction of Organisms and Populations
- Ecology (Organism, Population, Community and Biome)
- Definition of habitat and niche
- Organisms and Their Environment
- Introduction of Organisms and Environment
- Biomes
- Habitat
⇒ Key factors that lead to immense variations in physical as well as chemical conditions of varied habitats are: temperature, water, light, soil - Niche
- Responses to Abiotic Factors
- Responses to Abiotic Factors
- Living organisms deal with the extreme weather conditions through the following adaptations:
(i) Regulation
(ii) Conformation
(iii) Migration
(iv) Suspension
- Introduction of Organisms and Environment
- Population
- Population Attributes
- Population Ecology
- The population has certain attributes
- Birth Rate, Death Rate
- Sex Ratio
- Age Distribution
- Age Pyramid
- Population Size
- Population density
- Population Growth
- Life History Variation
- Population Attributes
- Population Interactions
- Population and Ecological Adaptations
- Organisms and Populations (Questions)
12 Ecosystem [Revision]
- Concept of Ecosystem
- Structure and Function of an Ecosystem
- Abiotic Factors
- Biotic Factors
- Interaction Between Biotic and Abiotic Factors
- Complexity of Ecosystems
- Biomes: Large Ecosystems
- Structure and Function of an Ecosystem
- Productivity
- Decomposition
- Ecological Pyramids
- Ecosystems Patterns
13 Biodiversity and Its Conservation [Revision]
- Biodiversity
- Species on Earth and Species in India
- How Many Species are there on Earth and How Many in India
- Importance of Species Diversity to the Ecosystem
- Species on Earth and Species in India
- Patterns of Biodiversity
- Loss of Biodiversity
- Conservation of Biodiversity
- Endangered Organisms
- Extinction
- Biodiversity and Its Conservation (Questions)
- In-situ Conservation
- Protected Areas
- National Parks (NP)
- Wild Life Sanctuaries (WLS)
- Biosphere Reserve (BR)
- Sacred Groves
- Ex-Situ Conservation
- Offsite Collections
- Gene Banks
