Class XII Biology NCERT Topics Covered


  • This course is useful for students wanted to clear basic concepts in Biology

  • Students studying in XII CLASS biology stream and want to score high in their Board exams

  • NEET students wanted to strengthen their NCERT BASICS


  • Classes takes by Ravi Sir experienced for 20+ years in teaching biology at major national brand institutes in India and abroad

  • First one week FREE CLASSES 

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  • Study at home with mobile, PC, laptop or tablet with internet connection

  • We recommend to use ear phone for better listening

  • Chapter exercise and sample questions discussion at end of each chapter

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  • Following NCERT Topics are covered in "NCERT Explained" Online class:


Chapter 1 : Reproduction in Organisms 

1.1 Asexual Reproduction
1.2 Sexual Reproduction

1.2.1 Pre-fertilisation Events Gametogenesis Gamete Transfer

1.2.2 Fertilisation

1.2.3 Post-fertilisation Events The Zygote Embryogenesis

Chapter 2 : Sexual Reproduction in Flowering Plants 

2.1 Flower – A Fascinating Organ of Angiosperms
2.2 Pre-fertilisation : Structures and Events

2.2.1 Stamen, Microsporangium and Pollen Grain

2.2.2 The Pistil, Megasporangium (ovule) and Embryo sac

2.2.3 Pollination

Agents of Pollination
Outbreeding Devices
Pollen-pistil Interaction

2.3 Double Fertilisation
2.4 Post-fertilisation: Structures and Events

2.4.1 Endosperm
2.4.2 Embryo
2.4.3 Seed

2.5 Apomixis and Polyembryony

Chapter 3 : Human Reproduction 

3.1 The Male Reproductive System
3.2 The Female Reproductive System
3.3 Gametogenesis
3.4 Menstrual Cycle
3.5 Fertilisation and Implantation
3.6 Pregnancy and Embryonic Development
3.7 Parturition and Lactation

Chapter 4 : Reproductive Health 

4.1 Reproductive Health – Problems and Strategies
4.2 Population Explosion and Birth Control
4.3 Medical Termination of Pregnancy
4.4 Sexually Transmitted Diseases
4.5 Infertility

Chapter 5 : Principles of Inheritance and Variation 

5.1 Mendel’s Laws of Inheritance
5.2 Inheritance of One Gene

5.2.1 Law of Dominance

5.2.2 Law of Segregation Incomplete Dominance Co-dominance

5.3 Inheritance of Two Genes

5.3.1 Law of Independent Assortment

5.3.2 Chromosomal Theory of Inheritance

5.3.3 Linkage and Recombination

5.4 Sex Determination

5.4.1 Sex Determination in Humans

5.5 Mutation
5.6 Genetic Disorders

5.6.1 Pedigree Analysis

5.6.2 Mendelian Disorders

Sickle-cell anaemia
5.6.3 Chromosomal disorders
Down’s Syndrome
Klinefelter’s Syndrome
Turner’s Syndrome

Chapter 6 : Molecular Basis of Inheritance 

6.1 The DNA

6.1.1 Structure of Polynucleotide Chain

6.1.2 Packaging of DNA Helix

6.2 The Search for Genetic Material

Transforming Principle

Biochemical Characterisation of Transforming Principle

6.2.1 The Genetic Material is DNA

6.2.2 Properties of Genetic Material (DNA versus RNA)

6.3 RNA World
6.4 Replication

6.4.1 The Experimental Proof

6.4.2 The Machinery and the Enzymes

6.5 Transcription

6.5.1 Transcription Unit

6.5.2 Transcription Unit and the Gene

6.5.3 Types of RNA and the process of Transcription

6.6 Genetic Code

6.6.1 Mutations and Genetic Code

6.6.2 tRNA– the Adapter Molecule

6.7 Translation
6.8 Regulation of Gene Expression

6.8.1 The Lac operon

6.9 Human Genome Project

6.9.1 Salient Features of Human Genome

6.9.2 Applications and Future Challenges

6.10 DNA Fingerprinting

Chapter 7 : Evolution 

7.1 Origin of Life
7.2 Evolution of Life Forms - A Theory
7.3 What are the Evidences for Evolution?
7.4 What is Adaptive Radiation?
7.5 Biological Evolution
7.6 Mechanism of Evolution
7.7 Hardy - Weinberg Principle
7.8 A Brief Account of Evolution
7.9 Origin and Evolution of Man

Chapter 8 : Human Health and Disease 

8.1 Common Diseases in Humans
8.2 Immunity

8.2.1 Innate Immunity

Physical barriers
Cellular barriers
Physiological barriers
Cytokine barriers

8.2.2 Acquired Immunity

8.2.3 Active and Passive Immunity

8.2.4 Vaccination and Immunisation

8.2.5 Allergies

8.2.6 Auto Immunity

8.2.7 Immune System in the Body

Lymphoid organs

8.3 AIDS
8.4 Cancer
8.5 Drugs and Alcohol Abuse



8.5.1 Adolescence and Drug/Alcohol Abuse

8.5.2 Addiction and Dependence

8.5.3 Effects of Drug/Alcohol Abuse

8.5.4 Prevention and Control

Chapter 9 : Strategies for Enhancement in Food Production 

9.1 Animal Husbandry

9.1.1 Management of Farms and Farm Animals Dairy Farm Management Poultry Farm Management

9.1.2 Animal Breeding

Interspecific hybridisation:Interspecific hybridisation:
Controlled breeding experiments

9.1.3 Bee-keeping

9.1.4 Fisheries

9.2 Plant Breeding

9.2.1 What is Plant Breeding?

Collection of variability:
Evaluation and selection of parents:
Cross hybridisation among the selected parents:
Selection and testing of superior recombinants:
Testing, release and commercialisation of new cultivars:

9.2.2 Plant Breeding for Disease Resistance

Methods of breeding for disease resistance

9.2.3 Plant Breeding for Developing Resistance to Insect Pests

9.2.4 Plant Breeding for Improved Food Quality


9.3 Single Cell Proteins
9.4 Tissue Culture

Chapter 10 : Microbes in Human Welfare 

10.1 Microbes in Household Products
10.2 Microbes in Industrial Products

10.2.1 Fermented Beverages

10.2.2 Antibiotics

10.2.3 Chemicals, Enzymes and other Bioactive Molecules

10.3 Microbes in Sewage Treatment

Primary treatment

Secondary treatment or Biological treatment

10.4 Microbes in Production of Biogas
10.5 Microbes as Biocontrol Agents

Biological control of pests and diseases

10.6 Microbes as Biofertilisers

Chapter 11 : Biotechnology Principles and Processes 

11.1 Principles of Biotechnology

Genetic engineering

11.2 Tools of Recombinant DNA Technology

11.2.1 Restriction Enzymes

11.2.2 Cloning Vectors

Origin of replication (ori)
Selectable marker
Cloning sites:
Vectors for cloning genes in plants and animals

11.2.3 Competent Host (For Transformation with Recombinant DNA)

11.3 Processes of Recombinant DNA Technology

11.3.1 Isolation of the Genetic Material (DNA)

11.3.2 Cutting of DNA at Specific Locations

11.3.3 Amplification of Gene of Interest using PCR

11.3.4 Insertion of Recombinant DNA into the Host Cell/Organism

11.3.5 Obtaining the Foreign Gene Product

11.3.6 Downstream Processing

Chapter 12 : Biotechnology and its Applications 

12.1 Biotechnological Applications in Agriculture

Bt Cotton:

Pest Resistant Plants

12.2 Biotechnological Applications in Medicine

12.2.1 Genetically Engineered Insulin

12.2.2 Gene Therapy

12.2.3 Molecular Diagnosis

12.3 Transgenic Animals

Normal physiology and development:

Study of disease:

Biological products:

Vaccine safety:

Chemical safety testing:

12.4 Ethical Issues


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

13.2 Populations

13.2.1 Population Attributes

13.2.2 Population Growth





Growth Models

Exponential growth

Logistic growth

13.2.3 Life History Variation

13.2.4 Population Interactions






Chapter 14 : Ecosystem 

14.1 Ecosystem–Structure and Function
14.2. Productivity
14.3 Decomposition
14.4 Energy Flow
14.5 Ecological Pyramids
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

Chapter 15 : Biodiversity and Conservation 

15.1 Biodiversity

Genetic diversit

Ecological diversity:

Ecological diversity:

15.1.1 How Many Species are there on Earth and How Many in India?

15.1.2 Patterns of Biodiversity

Latitudinal gradients

Species-Area relationships:

15.1.3 The importance of Species Diversity to the Ecosystem

15.1.4 Loss of Biodiversity

Causes of biodiversity losses:

(i) Habitat loss and fragmentation
(ii) Over-exploitation
(iii) Alien species invasions
(iv) Co-extinctions

15.2 Biodiversity Conservation

15.2.1 Why Should We Conserve Biodiversity?

15.2.2 How do we conserve Biodiversity?

In situ conservation
Ex situ Conservation

Chapter 16 : Environmental Issues 

16.1 Air Pollution and Its Control

16.1.1 Controlling Vehicular Air Pollution: A Case Study of Delhi

16.2 Water Pollution and Its Control

16.2.1 Domestic Sewage and Industrial Effluents

16.2.2 A Case Study of Integrated Waste Water Treatment

16.3 Solid Wastes

16.3.1 Case Study of Remedy for Plastic Waste

16.4 Agro-chemicals and their Effects

16.4.1 Case Study of Organic Farming

16.5 Radioactive Wastes
16.6 Greenhouse Effect and Global Warming
16.7 Ozone Depletion in the Stratosphere
16.8 Degradation by Improper Resource Utilisation and Maintenance
16.9 Deforestation

16.9.1 Case Study of People’s Participation in Conservation of Forests

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