Biology (Theory) ISC (Science) ISC Class 12 CISCE Syllabus 2025-26

• Definition and Meaning of Reproduction: 
• Purpose of Reproduction
• Basic Features of Reproduction: 
• Factors Responsible for Reproduction

• Flower
• Significance of flower

• Double Fertilization 
• Significance of Double Fertilization 
• Syngamy and Triple Fusion

• Gametogenesis

1. Spermatogenesis
2. Structure of human spermatozoan
3. Oogenesis
4. Structure of ovum

• Menstrual Cycle (Ovarian Cycle)
• Phases menstrual cycle

1. Menstrual phase
2. Follicular or proliferative phase
3. Ovulatory phase
4. Luteal or secretory phase

• Gastrulation
• Extra embryonic membranes
• Placenta
• Changes in embryo during pregnancy

• Population Explosion
• Reasons for population explosion
• Impact of population explosion
• Methods to control population explosion

• Introduction
• Some Sexually Transmitted Diseases
• Other diseases of the Reproductive Tract

• IVF-ET: in vitro fertilization and embryo transfer. 
• ICSI: Intracytoplasmic Sperm Injection  
• GIFT: Gamete Intrafallopian Transfer 
• ZIFT: Zygote Intrafallopian Transfer  
• IUT: Intra-Uterine Transfer
• IUI: Intra-Uterine insemination
• Adoption

• Reproductive and Child Health Care (RCH) Programme
  - Goals of RCH Programmes

• Mendel’s Principles of Heredity
• Mendelian inheritance - Mendel’s Laws of Heredity

 Sex Determination

1. Sex Determination in human beings 
2. Sex Determination in birds 
3. Sex Determination in honey bees  

• Linkage
• Types of linkage: Complete linkage and Incomplete linkage
• Linkage Groups
• Sex-linkage: Complete sex linkage and Incomplete sex linkage
• Crossing Over
• Morgan’s Experiments showing linkage and crossing over

• Genetic Disorders
• Examples of Genetic Disorders

• Packaging in Prokaryotes
• Packaging in Eukaryotes

• Operon
• Lactose or lac operon
• Lac operon consists of the following components:

1. Regulator gene (repressor gene) 
2. Promoter gene
3. Operator gene
4. Structural genes
5. Inducer

• Role of lactose

• Human Genome Project
• Goals of HGP
• Methodologies
• Salient Features of Human Genome
• Applications and Future Challenges

• DNA Fingerprinting Technique
• Steps involved in DNA finger printing
• Application of DNA fingerprinting

• Origin of life
• Theories of origin of life

1. Big Bang Theory
2. Theory of Panspermia
3. Theory of Spontaneous Generation or Abiogenesis
4. Theory of Biogenesis
5. Theory of Chemical Origin
6. Urey and Miller's experiment

• Evidence for Biological evolution:

1. Paleontological evidence
2. Evidence from Morphological and anatomical evidence
3. Embryological evidence
4. Molecular evidence
5. Evolution by natural selection (Industrial melanism)
6. Evolution by anthropogenic

• Speciation
• Modes to form New species

1. Intraspecific Speciation: Allopatric speciation and Sympatric speciation
2. Interspecific Speciation: Hybridisation

• Types of Immunity

1. Innate immunity or Inborn immunity

1. Epithelial surface
2. Antimicrobial substances in blood and
   tissues
3. Cellular factors in innate immunity
4. Fever
5. Acute phase proteins (APPs)

2. Acquired immunity

1. Active immunity

1. Natural Acquired Active immunity
2. Artificial Acquired Active immunity

      II. Passive immunity

1. Natural Acquired Passive immunity
2. Artificially Acquired Passive
   immunity

• Interferons – definition, source and function

• Structure of a typical antibody molecule
• Types of antibodies - IgG, IgA, IgM, IgD and IgE (function and occurrence, e,g. in serum, saliva, colostrum)

• Vaccination
• Immunization

• Primary lymphoid organs
• Secondary or peripheral lymphoid organs
• Cells of the immune system

• Introduction of Cancer
• Differences between normal cell and cancer cell
• Causes of cancer
• Cancer detection and diagnosis
• Treatment of cancer
• Scope of Immunology

• Introduction
• Some Sexually Transmitted Diseases
• Other diseases of the Reproductive Tract

Plant breeding

• Hybridization and its technique
  Steps of Hybridization technique
  Indian Hybrid Crops 
• Mutation Breeding

         -Plant Breeding for Developing a Resistance to Insect Pest

• Steps in Plant Breeding

1. Collection of Variability - Germplasm collection
2. Evaluation and selection of parents
3. Cross hybridisation among the selected parents
4. Selection and testing of superior recombinants
5. Testing, release and commercialisation of new cultivars

• Definition
• Introduction
• Tissue Culture Stages
• Processes in Tissue Culture

• Single cell protein (SCP)
• Advantages of Single-Cell Protein

• Agro-Complementary Occupations
• Animal Husbandry

• Proper Care for Optimal Yield
• Dairy Farm Management
• Protecting the Cattle from Diseases
• Livestock Management: Sheep, Goats, and Horses

• Poultry Farm Management
• Components of Poultry Farm Management
• Egg and Broiler Production
• Poultry Disease

Microbes in human welfare

• Microbes in food preparation

1. Dosa, Dhokla and Idli
2. Microbes as the Source of Food
3. Dairy Products

• Microbes in Household Food Processing
• Curd, Idli, Bread, Traditional drinks and food, Cheese
• Single cell protein (SCP)

Microbes in Industrial Production

1. Production of Alcoholic Beverages 
2. Production of organic acids 
3. Production of vitamins 
4. Production of Antibiotics 
5. Production of Enzymes 
6. Gibberellin production 

Composition of Sewage

Microorganisms in Sewage

Sewage treatment process includes four basic steps as follows:

1. Preliminary Treatment
2. Primary treatment (physical treatment)
3. Secondary treatment (biological treatment)
4. Tertiary treatment

• methanogens, biogas plant

• Microbes as Biocontrol Agents
• Examples of Microbial bio-control

• Process and Principles of Biotechnology
• Technique of gene cloning and rDNA technology 

• In agriculture: for production of crops tolerant to abiotic stresses (cold, drought, salt, heat); pest-resistant crops (Bt-crops, RNAi with reference to Meloidogyne incognita); biofortification (golden rice, wheat – Atlas 66, maize hybrids, iron fortified rice)
• Genetically Modified Organisms - BT Crops

• In medicine: Genetically Engineered Insulin, Gene therapy - with reference to the treatment of SCID, molecular diagnosis by PCR, ELISA and use of DNA/RNA probe.

• Transgenic animals for bioactive products like alpha-1-antitrypsin for emphysema, alpha-lactalbumin

1. Normal physiology and development
2. Study of disease
3. Biological products
4. Vaccine safety
5. Chemical safety testing

• Bio Piracy and Patents
• GEAC (Genetic Engineering Approval Committee)
• Biopiracy
• Patents
• Cyber Crime
• Software Piracy
• Hacking
• Cracking

• Vaccine safety testing
• Chemical safety testing
• Study of disease

• Definition of habitat and niche

Population Interactions

1. Predation (adaptations in organisms to avoid predation)
2. Competition (Interspecific, interference, Competitive exclusion, Competitive release, Gause's Competitive Exclusion Principle)
3. Parasitism 
   ⇒ Types of parasites: Ectoparasites, Endoparasites, Brood parasitism
4. Commensalism
5. Mutualism
6. Amensalism

• Introduction
• Factors Related to Population Growth

• Definition of stenothermal, Eurythermal, stenohaline and euryhaline), responses to abiotic factors (regulate, conform, migrate, suspend). Allen’s rule.

• Ecosystems
• Components of the environment - Abiotic and biotic, Productivity, Decomposition, Energy flow, Nutrient cycling
• The function of the Ecosystem:

1. Photosynthetically Active Radiation (PAR), Definition of PAR, 10% Law, standing crop and standing state.
2. Productivity of an ecosystem
3. Concept of trophic level in an ecosystem
4. Energy flow
5. Food chain
6. Food Web
7. Ecological pyramids
8. Decomposition
9. Biogeochemical cycle (Nutrient cycle)
10. Types of ecosystem
11. Ecosystem services ( Benefits)
12. Ecosystem Management

• Primary production
• Productivity
• Types of productivity

1. Primary productivity
   1) Gross primary productivity (GPP)
   2) Net-primary productivity (NPP)
2. Secondary productivity

• Fragmentation
• Leaching
• Catabolism
• Humification
• Mineralization
• Factors affecting rate of decomposition

• Introduction
• Trophic Levels of The Ecosystem

• Ecological Pyramids

1. Pyramid of biomass 
2. Pyramid of numbers 
3. Pyramid of energy 

• Limitations of ecological pyramids

Ecological succession

• Classification of ecological succession
  (i) Primary Succession
  (ii) Secondary Succession
• Succession of Plants
• Kinds of plant succession
  (i) Hydrarch Succession
  (ii) Xerarch Succession

• Nutrient Cycles
• Types of Nutrient cycles

Ecological services

• Categories of ecosystem services

1. Supporting services
2. Provisioning services
3. Regulating services
4. Cultural services

Following are the main ecological services: 

• Carbon fixation 
• Oxygen release 
• Pollination 

Patterns of Biodiversity

• Latitudinal and altitudinal gradients
• Species-Area relationships

• Ecological Role of Biodiversity
• Economic Role of Biodiversity
• Scientific Role of Biodiversity
• Rivet Popper hypothesis

• Loss of Biodiversity
• Causes of Biodiversity losses
  (i) Habitat loss and fragmentation
  (ii) Overexploitation
  (iii) Alien species invasions
  (iv) Co-extinctions

• Why should we conserve Biodiversity?
  (i) Narrowly utilitarian argument
  (ii) Broadly utilitarian argument
  (iii) Ethical argument
• How do we conserve Biodiversity?
  (i) In-situ methods: Biodiversity Hotspots and Sacred Groves
  (ii) Ex-situ Conservation - Zoological parks, Botanical parks, Wildlife Safari parks

• Red data book
• Categories in Red Data Book
  (1) Extinct
  (2) Extinct in the wild
  (3) Critically Endangered
  (4) Endangered
  (5) Vulnerable
  (6) Near Threatened
  (7) Least Concern
  (8) Data Deficient
  (9) Not Evaluated

• Meaning
• Types of Pollution 

1. Air pollution
2. Water Pollution
3. Noise Pollution 
4. Land Pollution 

• Classification of Pollutants

• Water Pollution
• Types of Water Pollutants
• Causes of Water Pollution
• Reasons of Water Pollution

• Integrated Wastewater Management

• Wastewater Treatment

1. Primary treatment
2. Secondary treatment or biological treatment
3. Tertiary treatment

• BOD
• Effect of sewage discharge on BOD and dissolved oxygen content in river

• Case studies of waste water treatment (FOAM and EcoSan)

• Soil Pollution
• Causes of Soil Pollution

• Agrochemicals
• Effects of Agrochemicals
• Biomagnification
• Eutrophication
• Case Study of Organic Farming

• Contribution of Ramesh Chandra Dagar

• Greenhouse effect
• Global warming
• Effects of global warming
• Prevention of global warming

• Deforestation
• Causes of deforestation

• Main provisions of Environmental Acts - Environmental Protection Act, Water (prevention and control of pollution), Air (prevention and control of pollution act).