CBSE Syllabus for Class 12 Biology

Course Structure for Class XII Biology  (2017-18)

Unit Title Marks
VI Reproduction 14
VII Genetics and Evolution 18
VIII Biology and Human Welfare 14
IX Biotechnology and its Applications 10
X Ecology and Environment 14
Total 70

Unit VI: Reproduction

Chapter 1: Reproduction in Organisms

Reproduction, a characteristic feature of all organisms for  continuation of species; Asexual reproduction Modes of reproduction-Asexual and sexual  reproduction; Modes-Binary fission, sporulation, budding, gemmule, fragmentation; vegetative  propagation in plants.

Chapter 2: Sexual Reproduction in Flowering Plants

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.

Chapter 3: 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).

Chapter 4: Reproductive Health

Need for reproductive health and prevention of sexually transmitted  diseases (STDs); Birth control – Need and Methods, Contraception and Medical Termination  of Pregnancy (MTP); Amniocentesis; Infertility and assisted reproductive technologies – IVF,  ZIFT, GIFT (Elementary idea for general awareness).

Unit VII: Genetics and Evolution

Chapter 5: Principles of Inheritance 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.

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 and human  ganeome project; DNA fingerprinting.

Chapter 7: 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.

Unit VIII: Biology and Human Welfare

Chapter 8: Human Health and Diseases

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.

Chapter 9: Strategies for Enhancement in Food Production

Improvement in food production : Plant breeding, tissue culture, single cell protein,  Biofortification, Apiculature and Animal husbandry.

Chapter 10: Microbes in Human Welfare

In household food processing, industrial production, sewage  treatment, energy generation and as biocontrol agents and biofertilizers.  Antibiotics; production and judicious use.

Unit IX: Biotechnology and Its Applications

Chapter 11: Biotechnology – Principles and Processes

Genetic engineering (Recombinant DNA technology).

Chapter 12: Biotechnology and its Application

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.

Unit X: Ecology and Environment

Chapter 13: Organisms and Populations

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.

Chapter 14: Ecosystem

Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy; nutrient cycles (carbon and phosphorous); ecological succession; ecological services – carbon fixation, pollination, seed dispersal, oxygen release (in brief).

Chapter 15: 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, sanctuaries and Ramsar sites.

Chapter 16: 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 climate change; ozone layer depletion; deforestation; any one case study as success story addressing environmental issue(s).


Time allowed: 3 Hours
Hours Max. Marks: 30 Marks

Evaluation Scheme
One Major Experiment Part A (Expt. No. 5, 6, 8, 9) 5 Marks
One Minor Experiment Part A (Expt. No. 2, 3, 4) 4 Marks
Slide Preparation Part A (Expt. No. 1, 7) 5 Marks
Spotting 7 Marks
Practical Record + Viva Voce 4 Marks
Project Record + Viva Voce 5 Marks
Total 30 Marks

A. List of Experiments  

  1. Study pollen germination on a slide.
  2. Collect and study soft from at least two different sites and study them for texture, moisture content, pH and water holding capacity. 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 organism.
  4. Study the presence of suspended particulate matter in air at two widely different sites.
  5. Study the plant population density by quadrat method.
  6. Study the plant population frequency by quadrat method.
  7. Prepare a temporary mount of onion root tip to study mitosis.
  8. Study the effect of different temperatures and three different pH on the activity of salivary amylase on starch.
  9. Isolate DNA from available plant material such as spinach, green pea seeds, papaya, etc.

B. Study/observation of the following (Spotting)

  1. Flowers adapted to pollination by different agencies (wind, insects, birds).
  2. Pollen germination on stigma through a permanent slide.
  3. Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary through permanent slides (from grasshopper! mice)
  4. Meiosis in onion bud cell, or grasshopper testis through permanent slides.
  5. T.S. of blastula through permanent slides (Mammalian).
  6. Mendelian inheritance using seeds of different colour/sizes of any plant.
  7. Prepared pedigree charts of any one of the genetic traits such as rolling of tongue, blood groups, ear lobes, widows peak and colour blindness.
  8. Controlled pollination – emasculation, tagging and bagging.
  9. Common disease causing organisms like Ascaris, Entamoeba, Plasmodium, Roundworm through permanent slides or specimens. Comment on symptoms of diseases that they cause.
  10. Two plants and two animals (models/virtual images) found in xeric conditions. Comment upon their morphological adaptations.
  11. Two plants and two animals (models/virtual images) found in aquatic conditions. Comment upon their morphological adaptations.

NCERT Solutions