CBSE Class 12 Biology Deleted Syllabus 2024-25 - Download PDF

• 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); Ques. 1,2,3,9,10,11,12

• 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 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 endosperms and embryos, development of seeds, and formation of 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 testis and ovaries; gametogenesis-spermatogenesis and oogenesis; 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 - needs and methods, contraception and medical termination of pregnancy (MTP); amniocentesis; infertility and assisted reproductive technologies - IVF, ZIFT, GIFT (elementary ideas for general awareness).

Chapter 5: Principles of Inheritance and Variation

Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete dominance, co-dominance, multiple alleles and inheritance of blood groups, pleiotropy; elementary idea of polygenic inheritance; chromosome theory of inheritance; chromosomes and genes; sex determination - in humans, birds and honey bees; linkage and crossover; sex-linked inheritance - haemophilia, colour blindness; Mendelian disorders in humans, thalassemia, chromosomal disorders in humans; Down's syndrome; Turner's and Klinefelter's syndromes. 

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 of biological evolution (palaeontology, comparative anatomy, embryology and molecular evidence); Darwin's contribution, modern synthetic theory of evolution; mechanism of evolution - variation (mutation and recombination)and natural selection with examples and types of natural selections; Gene flow, and genetic drift; Hardy: Weinberg's principle; adaptive radiation; human evolution. 

Chapter 8: Human Health and Diseases

Pathogens: parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm) and their control; Basic concepts of immunology - vaccines; cancer, HIV and AIDS; Adolescence - drug and 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-fertilizers. Antibiotics: production and judicious use.

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 and vaccine production, stem cell technology, gene therapy; genetically modified organisms - Bt crops; transgenic animals; biosafety issues, biopiracy and patents. 

Chapter 13: Organisms and Populations

Population interactions - mutualism, competition, predation, parasitism; population attributes -growth, birth rate, death rate, and age distribution. (Topics excluded: Organism and its environment, Major Abiotic Factors, Responses to Abiotic Factors, Adaptations)

Chapter-14: Ecosystem

Ecosystems: Patterns, components, productivity and decomposition; energy flow; pyramids of Numbers, Biomass, Energy (Topics excluded: Ecological Succession and Nutrient Cycles)

Chapter-15: Biodiversity and its Conservation

Biodiversity-Concepts, 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.

• Prepare a temporary mount to observe pollen germination.
• Study plant population density using the quadrat method.
• Study plant population frequency using the quadrat method.
• Prepare a temporary mount of onion root tips to study mitosis.
• Isolate DNA from available plant materials such as spinach, green pea seeds, papaya, etc.

• Flowers adapted to pollination by different agencies (wind, insects, birds).
• Pollen germination of stigma through a permanent slide or scanning electron micrograph.
• Identify the stages of gamete development, i.e., T.S. of testis and T.S. of ovaries through permanent slides (from grasshoppers/mice).
• Meiosis in onion bud cells or grasshopper testis through permanent slides.
• T.S. of the blastula through permanent slides (Mammalian).
• Mendelian inheritance using seeds of different colours/sizes of any plant.
• Prepared pedigree charts of any one of the genetic traits such as rolling of tongue, blood
• Groups, ear lobes, widow's peak and colour blindness.
• Controlled pollination - emasculation, tagging and bagging.
• Common diseases, organisms like Ascaris, Entamoeba, Plasmodium, and any fungus-causing ringworms through permanent slides, models, virtual images, or specimens.
• Comment on symptoms of diseases that they cause
• Model specimen showing symbolic association in root modules of leguminous plants, Cuscuta on host, lichens.
• Flashcard models showing examples of homologous and analogous organs.

• Beakers, flask, Petri plates, soil from different sites - sandy, clayey, loamy, small potted plants, aluminium foil, paintbrush, test tubes, starch solution, iodine, ice cubes, Bunsen burner/spirit lamp/water bath, large flowers, Maize inflorescence, model of developmental stages highlighting the morula and blastula of frogs, beads/seeds of different shapes/size/texture Ascaris, Cactus/Opuntia(model).

• Study of flowers adapted to pollination by different agencies (wind, insects).
• Identification of T.S of morula or blastula of frog (Model).
• Study of Mendelian inheritance patterns using beads/seeds of different sizes/textures.
• Prepare pedigree charts of genetic traits such as rolling of the tongue and colour blindness.
• Study emasculation, tagging, and bagging by trying out an exercise on controlled pollination.
• Identify common disease-causing organisms like Ascaris (model) and learn some common symptoms of the disease that they cause.
• Comment upon morphological adaptations of plants found in xerophytic conditions.