CBSE Class 12 Biology Syllabus 2026-27 Latest Curriculum and Marks Distribution

S.No.

Unit Name

Marks

VI

Reproduction

16

VII

Genetics and Evolution 

20

VIII

Biology and Human Welfare 

12

IX

Biotechnology and its Applications 

12

X

Ecology and Environment

10

Total

70

Unit

Chapter

Key Topics (Short & Simple)

VI. Reproduction

1. Sexual Reproduction in Flowering Plants

Flower structure, gametophytes, pollination, fertilisation, seeds & fruits, apomixis, parthenocarpy.

2. Human Reproduction

Male & female systems, gametogenesis, menstrual cycle, fertilisation, pregnancy, lactation.

3. Reproductive Health

STDs, contraception, MTP, amniocentesis, infertility, IVF, ZIFT, GIFT.

VII. Genetics & Evolution

4. Principles of Inheritance & Variation

Mendelian laws, deviations, polygenic inheritance, sex determination, disorders.

5. Molecular Basis of Inheritance

DNA/RNA structure, replication, transcription, translation, gene regulation, genome projects, DNA fingerprinting.

6. Evolution

Origin of life, evidences, Darwin’s theory, natural selection, genetic drift, Hardy-Weinberg, human evolution.

VIII. Biology & Human Welfare

7. Human Health & Diseases

Pathogens, diseases (malaria, dengue, etc.), immunity, vaccines, cancer, HIV, drug abuse.

8. Microbes in Human Welfare

Microbes in food, industry, sewage, energy, bio-control, bio-fertilizers, antibiotics.

IX. Biotechnology

9. Biotechnology – Principles & Processes

Recombinant DNA technology.

10. Biotechnology & Applications

Insulin, vaccines, stem cells, gene therapy, GMOs, transgenics, biosafety, patents.

X. Ecology & Environment

11. Organisms & Populations

Interactions, population growth, birth & death rate, age distribution.

12. Ecosystem

Components, productivity, energy flow, pyramids.

13. Biodiversity & Conservation

Importance, loss, conservation methods, hotspots, Red Data Book, reserves, national parks.

Evaluation Scheme

Marks

One Major Experiment (5)

5

One Minor Experiment (2&3)

4

Slide Preparation (1&4)

5

Spotting

7

Practical Record + Viva Voce

4

Investigatory Project and its Project Record + Viva Voce

5

Total

30

Class 12 Biology Practical Syllabus - Overview

Section

Details

Evaluation Scheme (30 Marks)

• Major Experiment – 5 marks 

• Minor Experiment – 4 marks 

• Slide Preparation – 5 marks 

• Spotting – 7 marks 

• Practical Record + Viva – 4 marks 

• Investigatory Project + Viva – 5 marks

Experiments

1. Prepare a temporary mount to observe pollen germination.

2. Study plant population density by the quadrat method. 

3. Study plant population frequency by the quadrat method.

4. Prepare a temporary mount of onion root tip (mitosis). 

5. Isolate DNA from plant material (spinach, peas, papaya).

Spotting (Observation & Identification)

1. Flowers adapted to pollination (wind, insects, birds). 

2. Pollen germination on stigma (slides/micrographs). 

3. Stages of gamete development (testis & ovary slides). 

4. Meiosis in onion bud cells/grasshopper testis. 

5. T.S. of blastula (mammal). 

6. Mendelian inheritance using seeds. 

7. Pedigree charts of genetic traits (tongue rolling, blood group, ear lobes, widow’s peak, colour blindness). 

8. Controlled pollination – emasculation, tagging, bagging. 

9. Common disease-causing organisms (Ascaris, Entamoeba, Plasmodium, fungi). 

10. Symbiotic associations (root nodules, Cuscuta, lichens). 

11. Homologous & analogous organs (flash cards/models).

Additional Lab Practicals

1. Study flowers adapted to pollination (wind, insects). 

2. Identify T.S. of morula/blastula (frog model). 

3. Study Mendelian inheritance with beads/seeds. 

4. Prepare pedigree charts of genetic traits. 

5. Controlled pollination (emasculation, tagging, bagging). 

6. Identify disease-causing organisms (Ascaris model). 

7. Study xerophytic plant adaptations.

Theory – Question Paper Design (Weightage)

• Knowledge & Understanding – 50% 

• Application of Concepts – 30% Analyse

• Evaluate & Create – 20%

Class 12 Biology Deleted Syllabus List 

Unit

Chapter

Deleted Topics

Unit VI – Reproduction

Chapter 1: Reproduction in Organisms

Complete Chapter

Unit VIII – Biology and Human Welfare

Chapter 9: Strategies for Enhancement in Food Production

Complete Chapter

Unit X – Ecology and Environment

Chapter 13: Organisms and Populations

13.1 Organism and Its Environment

• 13.1.1 Major Abiotic Factors

• 13.1.2 Responses to Abiotic Factors

• 13.1.3 Adaptations

• Summary (Para 2)

Questions: 1, 2, 3, 9, 10, 11, 12 

Unit X – Ecology and Environment

Chapter 14: Ecosystem

14.6 Ecological Succession

• 14.6.1 Succession of Plants

14.7 Nutrient Cycling

• 14.7.1 Ecosystem – Carbon Cycle

• 14.7.2 Ecosystem – Phosphorus Cycle

14.8 Ecosystem Services 

Unit X – Ecology and Environment

Chapter 16: Environmental Issues

Full Chapter

S. No

Competency

Description

Weightage (%)

1

Demonstrate Knowledge and Understanding

Tests recall of facts, concepts, definitions, diagrams, and basic understanding of Biology topics.

50%

2

Application of Knowledge / Concepts

Evaluates ability to apply biological concepts, principles, and processes to solve questions and real-life situations.

30%

3

Analyse, Evaluate and Create

Measures higher-order thinking skills such as analysing data, interpreting information, evaluating results, and forming logical conclusions.

20%

—

Total

Theory Paper Distribution

100%

S.No

Biology Class 12 Important Topics

1

Genetically Modified Organisms

2

Biotic and Abiotic Factors

3

Pollination

4

An Overview of Sexual Reproduction

5

Evolution of Bacteria

S.No

Important Study Material for Biology Class 12

1

Class 12 Biology Notes

2

Class 12 Biology NCERT Solutions

3

Class 12 Biology NCERT Books

4

Class 12 Biology Important Questions

5

Class 12 Biology Previous Year Question Paper