CBSE Class 12 Biology Syllabus 2026-27 PDF Download: Chapter-Wise Topics & Marking Scheme

Unit-VI Reproduction

Chapter 2: Sexual Reproduction in Flowering Plants

• Flower structure

• 
  

  • development of male and female gametophytes

• Pollination

• 
  

  • Types

  • Agencies and examples;

• Outbreeding devices

• Pollen-pistil interaction

• Double fertilisation

• Post-fertilisation events

• 
  

  • Development of endosperm and embryo

  • Development of the seed and formation of the fruit

• Special modes

• 
  

  • Apomixis

  • Parthenocarpy

  • Polyembryony

• Significance of seed dispersal and fruit formation.

Chapter 3: Human Reproduction

• Male and female reproductive systems

• Microscopic anatomy of the testis and the ovary

• Gametogenesis

• 
  

  • Spermatogenesis

  • Ogenesis

• Menstrual cycle

• 
  

  • Fertilisation

  • Embryo development up to blastocyst formation

  • Implantation

  • pregnancy and placenta formation (elementary idea)

  • parturition (elementary idea)

  • lactation (elementary idea).

Chapter 4: Reproductive Health

• Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs).

• Birth control

• 
  

  • Need and methods

  • Contraception and medical termination of pregnancy (MTP)

• Amniocentesis

• Infertility and assisted reproductive technologies

• 
  

  • IVF

  • ZIFT

  • GIFT (elementary idea for general awareness).

Unit-VII Genetics and Evolution

Chapter 5: Principles of Inheritance and Variation

• Heredity and variation

• 
  

  • Mendelian inheritance;

• Deviations from Mendelism

• 
  

  • incomplete dominance

  • Co-dominance

  • multiple alleles

  • inheritance of blood groups, pleiotropy

• An elementary idea of polygenic inheritance

• Chromosome theory of inheritance

• Chromosomes and genes

• Sex determination

• 
  

  • In humans

  • Birds

  • Honey bees

• Linkage and crossing over

• Sex linked inheritance

• 
  

  • Haemophilia

  • Colour blindness

• Mendelian disorders in humans

• 
  

  • Thalassemia

• Chromosomal disorders in humans

• 
  

  • Down's syndrome

  • Turner's syndrome

  • Klinefelter's syndrome.

Chapter 6: Molecular Basis of Inheritance

• Search for genetic material and DNA as genetic material

• Structure of DNA and RNA

• DNA packaging; DNA replication

• Central Dogma

• Transcription, genetic code, translation

• Gene expression and regulation

• 
  

  • Lac operon

• Genome, Human and rice genome projects

• DNA fingerprinting.

Chapter-7: Evolution

• Origin of life

• Biological evolution and evidence for biological evolution

• Darwin's contribution

• 
  

  • Modern synthetic theory of evolution

• Mechanism of evolution

• 
  

  • Variation (mutation and recombination)

  • Natural selection with examples

  • Types of natural selection

• Gene flow and genetic drift

• Hardy - Weinberg's principle

• Adaptive radiation

• Human evolution.

Unit-VIII Biology and Human Welfare

Chapter 8: Human Health and Diseases

• Pathogens

• Parasites causing human diseases and their control

• Basic concepts of immunology

• 
  

  • Vaccines

  • Cancer

  • HIV and AIDS

• Adolescence

• 
  

  • Drug

  • Alcohol abuse.

Chapter 10: Microbes in Human Welfare

• Microbes in food processing

• 
  

  • Industrial production

  • Sewage treatment,

• Energy generation and microbes as bio-control agents and bio-fertilisers.

• Antibiotics: production and judicious use.

Unit-IX Biotechnology and its Applications

Chapter-11: Biotechnology - Principles and Processes

Genetic Engineering (Recombinant DNA Technology).

Chapter 12: Biotechnology and Its Applications

• Application of biotechnology in health and agriculture

• 
  

  • Human insulin

  • Vaccine production

  • Stem cell technology

  • Gene therapy

• Genetically modified organisms

• 
  

  • Bt crops;

• Transgenic animals

• Biosafety issues

• 
  

  • Biopiracy

  • patents

Unit-X Ecology and Environment

Chapter 13: Organisms and Populations

• Population interactions

• 
  

  • Mutualism

  • Competition

  • Predation

  • Parasitism

• Population attributes

• 
  

  • growth, birth rate, and death rate

  • Age distribution.

Chapter-14: Ecosystem

• Ecosystems

• 
  

  • Patterns

  • Components

  • Productivity and decomposition

• Energy flow

• Pyramids of number

• 
  

  • Biomass

  • Energy

Chapter 15: Biodiversity and Its Conservation

• Biodiversity

• 
  

  • concept, patterns, importance

• Loss of biodiversity

• Biodiversity conservation

• Hotspots

• 
  

  • Endangered organisms

  • Extinction

  • Red Data Book

  • Sacred Groves

  • Biosphere reserves

  • National parks

  • Wildlife, sanctuaries and Ramsar sites.

Units

Topics

Marks

Unit 6

Reproduction

16

Unit 7

Genetics and Evolution

20

Unit 8

Biology and Human Welfare

12

Unit 9

Biotechnology and Its Applications

12

Unit 10

Ecology and Environment

10

Total

70