Biology (Botany and Zoology) HSC Science Class 12 Tamil Nadu Board of Secondary Education Syllabus 2024-25

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

• Apomixis
• Classification of apomixis

1. Recurrent apomixis
2. Non-recurrent apomixis
3. Adventive apomixis

• Mendelism
• Father of Genetics - Gregor Johann Mendel
• Reasons for Mendel's success
• Advantages of selecting pea plant for experiment by Mendel

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

• Monohybrid Cross
• Representation of a Gene

• Back cross 
• Test cross 

• Dihybrid Cross
• Reasons for Mendel’s Success
• Reciprocal Cross

• Mechanism of Crossing Over
• Types of Crossing Over
• Importance of Crossing Over
• Recombination
• Genetic Mapping

• Types of mutation
• Mutagenic agents
• Chromosomal mutations

•  Fermentation
• Single Cell Protein (SCP)

• Genetic Engineering
• Steps involved in Recombinant DNA Technology 

• Restriction Enzymes
• DNA Ligase
• Alkaline Phosphatase
• Vectors
• Competent Host (For Transformation with Recombinant DNA)

• Direct or Vectorless Gene Transfer
• Indirect or Vector-Mediated Gene Transfer

• Insertional Inactivation - Blue-White Colony Selection Method
• Antibiotic resistant markers
• Replica plating technique
• Molecular Techniques - Isolation of Genetic Material and Gel Electrophoresis
• Nucleic Acid Hybridization - Blotting Techniques
• Bioassay for Target Gene Effect
• Genome Sequencing and Plant Genome Projects
• Evolutionary pattern assessed using DNA
• Genome editing and CRISPR - Cas9
• RNA Interference (RNAi)

• Herbicide Tolerant – Glyphosate
• Herbicide Tolerant - Basta
• Insect resistance - Bt Crops
• Virus Resistance
• FlavrSavr Tomato
• Golden rice - Biofortification
• Polyhydroxybutyrate (PHB)
• Polylactic acid (PLA)
• Green Fluorescent Protein (GFP)
• Biopharming
• Bioremediation
• Biofuel: Algal Biofuel
• Bioprospecting

1. Healthcare Biotechnology 
2. Agriculture 
3. Gene therapy 
4. Genetically Modified Organisms (GMOs) 

• Laboratory Facilities for PTC 
• Technique Involved in PTC
• Types of Plant tissue cultures

• Somatic Embryogenesis 
• Organogenesis

• Micropropagation of Banana
• Artificial Seed
• Virus-free plants

• Germplasm Conservation
• Cryopreservation (–195.C)

• Patents
• Biosafety and Bioethics

• Definitions of ecology
• Ecological hierarchy
• Branches of Ecology
• Habitat and Niche
• Ecological equivalents

• Climatic Factors
• Edaphic factors
• Topographic factors
• Biotic factors

• Dispersal by Wind (Anemochory)
• Dispersal by Water (Hydrochory)
• Dispersal by Animals (Zoochory)
• Dispersal by Explosive Mechanism (Autochory)

• 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

• Causes of Succession
• Characteristics of ecological succession
• Types of succession
• Process of succession
• Classification of plant succession
• Significance of Plant Succession

• Effects of Global Warming
• Sources of Green House Gases Emission (Natural and Anthropogenic)
• Strategies to deal with Global Warming
• Ozone depletion
• Effects of Ozone depletion

• Agro forestry
• Social forestry
• Major activities of forestry extension centres

• International Union for Conservation of Nature (IUCN)
• Endemic Centres and Endemic Plants

• Environmental benefits of Rain Water Harvesting
• Importance of Lakes

• Biodiversity Impact Assessment (BIA)

• Biofertilizers

Plant breeding

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

         -Plant Breeding for Developing a Resistance to Insect Pest

• Plant Introduction
• Selection
• Hybridization
• Heterosis
• Mutation Breeding
• Polyploid Breeding
• Green Revolution
• Plant Breeding for Developing Resistance to diseases
• Plant Breeding for Developing Resistance to Insect Pests

• New Plant Engineering Techniques / New Breeding Techniques (NBT)

• Cereals

• Major Cereals

• Millets (Siru Thaniyangal)
• Minor Millets
• Pulses
• Vegetables
• Fruits 
• Nuts
• Sugars
• Oil Seeds
• Beverages

• Spices
• Condiment

• Seasoning of wood
• Grain, Texture, and Figure of wood

• Dye and its Types
• Uses and Adverse Effects of Dyes

• Perfumes

• Siddha system of medicine
• Ayurveda system of medicine

• Mushroom cultivation
• Single Cell Protein (SCP) Production
• Seaweed Liquid Fertilizer
• Organic farming
• Terrarium
• Cultivation of Medicinal and Aromatic Plants

• 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

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

• 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

• Intra-uterine insemination (IUI)
• In vitro fertilization (IVF) or Test tube baby
• Zygote intra-fallopian transfer (ZIFT)
• Intra uterine transfer (IUT)
• Gamete intra-fallopian transfer (GIFT)
• Intra-cytoplasmic sperm injection (ICSI)
• Surrogacy
• Male infertility

• Ultrasound scanning
• Amniocentesis
• Chorionic villus sampling (CVS)
• Foetoscope

• ABO blood types
• Rhesus or Rh Factor

• Fisher and Race hypothesis
• Wiener Hypothesis
• Incompatibility of Rh Factor – Erythroblastosis foetalis

• Prevention of Erythroblastosis foetalis

 Sex Determination

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

• X-linked (sex-linked) genes
• Y-linked (Holandric) genes

1. Colour blindness
2. Haemophilia (Bleeder’s disease)

• Preparation of Karyotype
• Applications of Karyotyping
• Human Karyotype

• Genetic Disorders
• Examples of Genetic Disorders

• Pentose sugar
• Nitrogenous bases
• The phosphate functional group
• Nucleoside and nucleotide

• Packaging in Prokaryotes
• Packaging in Eukaryotes

• Functions of DNA:

1. Heterocatalytic function
2. Autocatalytic function

Process of semicoservative replication 

• Activation of Nucleotides 
• Point of Origin or Initiation point 
• Unwinding of DNA molecule 
• Replicating fork 
• Synthesis of new strands 
• Leading and Lagging strand 
• Formation of daughter DNA molecules

• Characteristics of Genetic code 
• Mutations and Genetic Code 

• Mechanism of Translation

• 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

• Paleontological evidences
• Evidences from comparative anatomy

1. Homologous structures
2. Analogous structures
3. Vestigial organs 
4. Connecting link
5. Atavistic organs

• Embryological evidences

1. Molecular evidences

• Lamarck’s theory

• The main objection to Lamarckism 
• Neo-Lamarckism

• Darwin’s theory of Natural Selection

1. Objections to Darwinism
2. Neo Darwinism 

• Mutation theory

1. Salient features of Mutation Theory

• Modern synthetic theory
• Evolution by anthropogenic sources

1. Natural Selection (Industrial melanism)

• Adaptive Radiation 

1. Darwin’s finches

• Innate immunity
• Acquired immunity

• Components of acquired immunity
• Types of acquired immunity

• Immune responses

• Primary immune response
• Secondary immune response

• Lymphoid organs

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

• Antigens

• Types of antigens

• Antibodies
• Antigen -antibody interaction 

• Binding force of antigen - antibody reaction
• Different types of antigen and antibody reactions

• Vaccines
• Vaccination and immunization
• Hypersensitivity 

• Structure of HIV
• HIV Transmission

• Tumour immunology
• Immunotherapy of cancer

• Signs and symptoms of mental depression

• 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

• Microorganisms involved in bioremediation

• 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

• Niche (or) Ecological Niche

• Temperature
• Adaptations to temperature
• Light
• Water
• Soil 
• Wind
• Humidity
• Altitude

• Characters of a biome
• Aquatic Biomes
• Terrestrial biomes
• Major Biomes of the Earth

• Tundra Biome 
• Taiga Biome 
• Grassland Biome
• Alpine biome
• Forest biomes
• Desert biomes

Population

•  Natality

1. Absolute Natality
2. Realized Natality

•  Mortality

1. Absolute Mortality
2. Realized Mortality

• Sex ratio
• Age distribution and Age pyramid
• Population Growth 

• Growth Models / Curves
• S-Shaped growth form (sigmoid growth)

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

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

• Habitat Loss
• Habitat fragmentation
• Over exploitation
• Exotic species invasion
• Global Climate changes
• Shifting or Jhum cultivation (Slash-and-burn agriculture)
• Coextinctions
• Intensive agriculture
• Loss of biodiversity
• Hotspots
• Endangered organisms
• Extinction

• Red Data Book

• In-situ Conservation 

• Protected Areas
• National Parks (NP)
• Wild Life Sanctuaries (WLS)
• Biosphere Reserve (BR)
• Sacred Groves

• Ex-Situ Conservation

• Offsite Collections
• Gene Banks

• 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

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

• Integrated Wastewater Management

• Wastewater Treatment

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