CBSE Board Biology Syllabus for Class 12

COURSE STRUCTURE
CLASS 12

BIOLOGY

1.    Reproduction

Reproduction in organisms: Reproduction, a characteristic feature of all organisms for
continuation of species; Modes of reproduction-A sexual and sexual reproduction; Modes-
Binary fission, sporulation, budding, gemmule, fragmentation; vegetative propagation in
plants.
Sexual reproduction in flowering plant: Flower structure; Development of male and female
gametophytes; Pollination-types, agencies and examples; Outbreedings devices; Pollen-
Pistil interaction; Double fertilization; Post fertilization events-Development of endosperm
and embryo, Development of seed and formation of fruit; Special modes-apomixis,
parthenocarpy, polyembryony; Significance of seed and fruit formation.
Human Reproduction: Male and female reproductive systems; Microscopic anatomy of
testis and ovary; Gametogenesis-spermatogenesis & oogenesis; Menstrual cycle;
Fertilisation embryo development upto blastocyst formation, implantation; Pregnancy and
placenta formation (Elementary idea); Parturition (Elementary idea); Lactation (Elementary
idea).

II. Genetics and Evolution
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, honey bee; Linkage and
crossing over; Sex linked inheritance - Haemophilia, Colour blindness; Mendelian disorder
in humans - Thalassemia; chromosomal disorders in humans; Down's syndrome, Turner's
and Klinefelter's syndromes.
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 and human ganeome project; DNA finger printing.
Evolution: Origin of life; Biological evolution and evidences for biological evolution
(Paleontological, 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, types of natural
selection; Gene flow and genetic drift; Hardy - Weinberg's principle; Adaptive Radiation;
Human evolution.

III. Biology and Human Welfare
Health and Disease: Pathogens; parasites causing human diseases (Malaria, Filariasis,
Ascariasis, Typhoid, Pneumonia, common cold, amoebiasis, ring worm); Basic concepts
of immunology - vaccines; Cancer, HIV and AIDs; Adolescene, drug and alcholol abuse.
Improvement in food production : Plant breeding, tissue culture, single cell protein,
Biofortification, Apiculature and Animal husbandry.
Microbes in human welfare: In household food processing, industrial production, sewage
treatment, energy generation and as biocontrol agents and biofertilizers.

IV. Biotechnology and Its Applications
Principles and process of Biotechnology: Genetic engineering (Recombinant DNA
technology).
Application of Biotechnology in health and agriculture: Human insulin and vaccine
production, gene therapy; Genetically modified organisms-Bt crops; Transgenic Animals;
Biosafety issues- Biopiracy and patents.

V. Ecology and Environment
Organisms and environment: Habitat and niche, Population and ecological adaptations;
Population interactions-mutualism, competition, predation, parasitism; Population attributesgrowth,
birth rate and death rate, age distribution.
Ecosystems: Patterns, components; productivity and decomposition; Energy flow; Pyramids
of number, biomass, energy; Nutrient cycling (carbon and phosphorous); Ecological
succession; Ecological Services-Carbon fixation, pollination, oxygen release.
Biodiversity and its conservation: Concept of Biodiversity; Patterns of Biodiversity;
Importance of Biodiversity; Loss of Biodiversity; Biodiversity conservation; Hotspots,
endangered organisms, extinction, Red Data Book, biosphere reserves, National parks
and sanctuaries.
Environmental issues: Air pollution and its control; Water pollution and its control;
Agrochemicals and their effects; Solid waste management; Radioactive waste management;
Greenhouse effect and global warning; Ozone depletion; Deforestation; Any three case
studies as success stories addressing environmental issues.

Practicals

A. List of Experiments
1. Study pollen germination on a slide.
2. Collect and study soil from at least two different sites and study them for texture, moisture
content, pH and water holding capacity of soil. Correlate with the kinds of plants found in
them.
3. Collect water from two different water bodies around you and study them for pH, clarity
and presence of any living organisms.
4. Study the presence of suspended particulate matter in air at the two widely different sites.
5. Study of plant population density by quadrate method.
6. Study of plant population frequency by quadrate method.
7. Prepare a temporary mount of onion root tip to study mitosis.
8. To study the effect of the different temperatures and three different pH on the activity of
salivary amylase on starch.

Study/observation of the following (Spotting)
1. Flowers adapted to pollination by different agencies (wind, insect).
2. Pollen germination on stigma through a permanent slide.
3. Identification of stages of gamete development i.e. T.S. testis and T.S. ovary through
permanent slides (from any mammal).
4. Meiosis in onion bud cell or grass hopper testis through permanent slides.
5. T.S. of blastula through permanent slides.
6. Mendelian inheritance using seeds of different colour/sizes of any plant.
7. Prepared pedigree charts of genetic traits such as rolling of tongue, blood groups, widow's
peak, colour blindness.
8. Exercise on controlled pollination - Emasculation, tagging and bagging.
9. Identification of common disease causing organisms like Ascaris, Entamoeba, Plasmodium,
ringworm through permanent slides or specimens. Comment on symptoms of disease that
they cause.
10. Two plants and two animals found in xerophytic conditions. Comment upon their
morphological adaptations.
11. Plants and animals found in aquatic conditions. Comment upon their morphological
adaptations.