BiologySyllabus Of Grade XII - BIOLOGY (THEORY - BI1206, PRACTICAL - PBI1206)
The Grade XII Biology syllabus is divided into two compulsory parts - Biology (Theory) and Biology (Practical). Separate marks are given for each unit, with a total of 70 marks for theory and 30 marks for practical.
Focus areas: reproduction, genetics and evolution, human health and welfare, biotechnology, ecology and environment, along with hands-on experiments, investigatory project work and viva voce.
Theory: 70 MarksPractical: 30 MarksTotal: 100 Marks
Instructions: This syllabus is divided into two parts. All units in both theory and practical are compulsory. The tables below summarise units and marks, followed by detailed unit-wise content.
Sexual reproduction in flowering plants - flower structure; male and female gametophytes; types and agents of pollination; outbreeding devices; pollen-pistil interaction; double fertilisation.
Post-fertilisation events - development of endosperm and embryo, seed formation, fruit formation; apomixis, parthenocarpy, polyembryony; significance of seeds and fruits.
Human reproduction - male and female reproductive systems; microscopic structure of testis and ovary; spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development to blastocyst, implantation; elementary idea of pregnancy, placenta, parturition and lactation.
Reproductive health - need and importance; prevention of sexually transmitted diseases (STDs); birth control, contraception and MTP; amniocentesis; infertility and assisted reproductive technologies (IVF, ZIFT, GIFT - elementary awareness).
Grade XII · Biology (Theory) · Unit 2
Unit 2 · Genetics and Evolution (18 Marks)
18 Marks
Heredity and variation - Mendel’s experiments and laws of inheritance.
Deviations from Mendelism - incomplete dominance, co-dominance, multiple alleles, inheritance of blood groups, pleiotropy; elementary idea of polygenic inheritance.
Chromosome theory of inheritance - relationship between chromosomes and genes; sex determination in humans, birds and honeybee.
Linkage and crossing over; sex-linked inheritance - haemophilia and colour blindness; Mendelian disorders - thalassemia; chromosomal disorders - Down’s, Turner’s and Klinefelter’s syndromes.
Molecular basis of inheritance - search for genetic material; DNA as genetic material; structure of DNA and RNA; DNA packaging and replication.
Central dogma; transcription, genetic code, translation; gene expression and regulation (Lac operon concept); genome, Human Genome Project and DNA fingerprinting.
Grade XII · Biology (Theory) · Unit 3
Unit 3 · Biology and Human Welfare (14 Marks)
14 Marks
Health and disease - pathogens and parasites causing human diseases: malaria, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm.
Basic concepts of immunology; vaccines and vaccination; cancer, HIV and AIDS.
Adolescence-related issues - drug and alcohol abuse (elementary awareness).
Improvement in food production - plant breeding, tissue culture, single cell protein, biofortification; apiculture and animal husbandry.
Microbes in human welfare - role in household products, industrial production, sewage treatment, biogas/energy generation, biocontrol agents and biofertilisers.
Grade XII · Biology (Theory) · Unit 4
Unit 4 · Biotechnology and its Applications (10 Marks)
10 Marks
Principles and processes of biotechnology - brief idea of genetic engineering (recombinant DNA technology).
Applications of biotechnology in health - production of human insulin, vaccines; gene therapy (elementary idea).
Biosafety concerns, biopiracy and patents - basic awareness and ethical issues.
Grade XII · Biology (Theory) · Unit 5
Unit 5 · Ecology and Environment (14 Marks)
14 Marks
Ecosystems - patterns and components; productivity and decomposition; energy flow in an ecosystem.
Ecological pyramids of number, biomass and energy; nutrient cycling with reference to carbon and phosphorus.
Ecological succession - basic idea; ecological services such as carbon fixation, pollination and oxygen release.
Biodiversity - concept, patterns and importance; loss of biodiversity and its consequences.
Biodiversity conservation - hotspots, endangered species, extinctions, Red Data Book, biosphere reserves, national parks and wildlife sanctuaries.
Environmental issues - air and water pollution and their control; agrochemicals and their effects; solid and radioactive waste management; greenhouse effect, global warming, ozone depletion and deforestation; examples of three success stories in environmental management.
Biology (Practical) - PBI1206
Grade XII · Biology (Practical) · Unit 1
Unit 1 · Experiments and Spotting (20 Marks)
20 Marks
Study pollen germination on a slide.
Collect and compare soil from at least two sites - texture, moisture content, pH and water-holding capacity; relate to types of vegetation.
Collect water from two different water bodies - observe pH, clarity and presence of living organisms.
Study suspended particulate matter in air at two different sites.
Determine plant population density using quadrat method.
Determine plant population frequency using quadrat method.
Prepare a temporary mount of onion root tip to study mitosis.
Study the effect of different temperatures and three pH levels on salivary amylase activity on starch.
Grade XII · Biology (Practical) · Unit 2
Unit 2 · Record of One Investigatory Project and Viva (05 Marks)
5 Marks
Maintain record of one investigatory project in Biology and face viva based on the work.
Illustrative project areas include:
- Flowers adapted to different pollination agencies (wind, insect), with suitable examples.
- Pollen germination on stigma (through permanent slide).
- Identification of stages of gamete development - T.S. testis and T.S. ovary (permanent slides of a mammal).
- Meiosis in onion bud cells or grasshopper testis (permanent slides).
- T.S. of blastula (permanent slide).
- Mendelian inheritance using seeds showing variation in colour/size.
- Prepared pedigree charts for traits such as rolling of tongue, blood groups, ear lobes, widow’s peak or colour blindness.
Grade XII · Biology (Practical) · Unit 3
Unit 3 · Class Record and Viva based on Experiments (05 Marks)
5 Marks
Well-maintained class practical record and viva voce based on the experiments performed.
Illustrative viva/record components include:
- Exercise on controlled pollination - emasculation, tagging and bagging.
- Identification of common disease-causing organisms (Ascaris, Entamoeba, Plasmodium, ringworm) from slides/specimens and comment on symptoms.
- Identification of two plants and two animals from xeric habitats with comments on morphological adaptations.
- Identification of plants and animals from aquatic habitats with comments on morphological adaptations.
Referred Books
Biology Textbook for Class XII, Published by NCERT
