CBSE Class 12 Biology Syllabus for academic session 2026-27
This page contains the CBSE Class 12 Biology syllabus for the academic session 2026-27, as prescribed by CBSE curriculum.
The present curriculum provides the students with updated concepts along with an extended exposure to contemporary areas of the subject. The curriculum also aims at emphasizing the underlying principles that are common to animals, plants and microorganisms as well as highlighting the relationship of Biology with other areas of knowledge. The format allows a simple, clear, sequential flow of concepts. It links the discoveries and innovations in biology to everyday life such as environment, industry, health and agriculture. The Biology curriculum is expected to enable the students to:
•
develop capacities for observation, experimentation, documentation, and familiarity with quantitative reasoning and multi-disciplinary approaches.
•
engender sensitivity towards biological issues (environment, health) in their surroundings and be aware of how citizens can contribute to their local communities and to science.
•
be aware of bioethical concerns that arise in biology today.
•
understand the integration of different fields of biology and highlight the interconnections between these fields.
•
be exposed to diverse careers in the life sciences.
This curriculum of Biology will help in achieving the following curricular goals and competencies delineated in the National Curriculum Framework for School Education 2023:
CG-3 Explores the structure and function of the living world at the cellular level
C-3.1 Explains the role of cellular components (nucleus, mitochondria, endoplasmic reticulum, vacuoles, chloroplast, cell wall), including the semi permeability of cell membrane in making cell the structural basis of living organisms and functional basis of life processes
C-3.2 Analyses similarities and differences in the life processes involved in nutrition (photosynthesis in plants; absorption of nutrients in fungi; digestion in animals), transport (transport of water in plants; circulation in animals), exchange of materials (respiration and excretion), and reproduction
C-3.3 Describes mechanisms of heredity (in terms of DNA, genes, chromosomes) and variation (as changes in the sequence of DNA)
CG-4 Explores interconnectedness between organisms and their environment
C-4.1 Applies the knowledge of cellular diversity in organisms along with the ecological role organisms play (autotrophic/heterotrophic nutrition) to classify them into five-kingdoms
C-4.2 Illustrates different levels of organisations of living organisms (from molecules to organisms)
C-4.3 Analyses different levels of biological organisation from organisms to ecosystems and biomes along with interactions that take place at each level
C-4.4 Analyses patterns of inheritance of traits in terms of Mendel’s laws and its consequences at a population level (using models and/or simulations)
C-4.5 Analyses evidences of biological evolution demonstrating the consequences of the process of natural selection in terms of changes in allele frequency in population, structure, and function of organisms
CG-5 Draws linkages between scientific knowledge and knowledge across other curricular areas
C-5.3 Applies scientific principles to explain phenomena in other subjects (sound pitch, octave, and amplitude in music; use of muscles in dance form and sports)
CG-6 Understands and appreciates the contribution of India through history and the present times to the overall field of Science, including the disciplines that constitute it
C-6.1 Knows and explains the significant contributions of India to all matters (concepts, explanations, methods) that are studied within the curriculum in an integrated manner
CG-7 Develops awareness of the most current discoveries, ideas, and frontiers in all areas of scientific knowledge in order to appreciate that Science is ever evolving, and that there are still many unanswered questions
C-7.1 States concepts that represent the most current understanding of the matter being studied ranging from mere familiarity to conceptual understanding of the matter as appropriate to the developmental stage of the students C-7.2 States questions related to matters in the curriculum for which current scientific understanding is well-recognised to be inadequate
CG-8 Explores the nature of Science by doing Science
C-8.1 Develops accurate and appropriate models (including geometric, mathematical, graphical) to represent real-life events and phenomena using scientific principles and use these models to manipulate variables and predict results C-8.2 Designs and implements a plan for scientific inquiry (formulates hypotheses, makes predictions, identifies variables, accurately uses scientific instruments, represents data primary and secondary in multiple modes, draws inferences based on data and understanding of scientific concepts, theories, laws, and principles, communicates findings using scientific terminology)
It is expected that the students would get an exposure to various branches of Biology in the curriculum in a more contextual and systematic manner as they study its various units. (NCFSE-2023)
Attainment of the competencies shall be done through transaction of the curriculum using appropriate pedagogy; these shall be assessed through an integrated evaluation scheme.
Marking Scheme (Theory)
Time: 03 Hours
Max. Marks: 70
Unit
Title
Marks
VI
Reproduction
16
VII
Genetics and Evolution
20
VIII
Biology and Human Welfare
12
IX
Biotechnology and its Applications
12
X
Ecology and Environment
10
Total
70
Syllabus
Unit-VI Reproduction
Chapter-1: Sexual Reproduction in Flowering Plants
Flower structure; development of male and female gametophytes; pollination – types, agencies and examples; out breeding 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 dispersal and fruit formation.
Chapter-2: Human Reproduction
Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis -spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development upto blastocyst formation, implantation; pregnancy and placenta formation (elementary idea); parturition (elementary idea); lactation (elementary idea).
Chapter-3: 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-4: 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 bee; linkage and crossing over; 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-5: 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-6: Evolution
Origin of life; biological evolution and evidences for biological evolution (paleontology, comparative anatomy, embryology and molecular evidences); 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-7: Human Health and Diseases
Pathogens; parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ring worm) and their control; Basic concepts of immunology – vaccines; cancer, HIV and AIDS; Adolescence – drug and alcohol abuse.
Chapter-8: 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.
Unit-IX Biotechnology and its Applications
Chapter-9: Biotechnology – Principles and Processes
Genetic Engineering (Recombinant DNA Technology).
Chapter-10: 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.
Unit-X Ecology and Environment
Chapter-11: Organisms and Populations
Population interactions – mutualism, competition, predation, parasitism; population attributes – growth, birth rate and death rate, age distribution.
Chapter-12: Ecosystem
Ecosystems: Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy.
Chapter-13: Biodiversity and its Conservation
Biodiversity-Concept, 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.
The following topics are included in the syllabus but will be assessed only formatively to reinforce understanding without adding to summative assessments. The reduces academic stress while ensuring meaningful learning. Schools can integrate these with existing chapters as they align well. Relevant NCERT textual material is enclosed for reference.
Environmental Issues (available as a part of CBSE Reading Material):
Air pollution and its control, Water pollution and its control, Solid Wastes, Agro-chemicals and their effects, Radioactive wastes, Greenhouse effect and global warming, Ozone depletion in the stratosphere, Degradation by improper resource utilization and maintenance, deforestation.
Marking Scheme (Practicals)
Time allowed: 3 hours
Max. Marks: 30
Evaluation Scheme
Marks
One Major Experiment
5
5
One Minor Experiment
2 & 3
4
Slide Preparation
1 & 4
5
Spotting
7
Practical Record + Viva Voce
(Credit to the student’s work over the academic session may be given)
Investigatory Project and its Project Record + Viva Voce
4
5
Total
30
A. List of Experiments
1.
Prepare a temporary mount to observe pollen germination.
2.
Study the plant population density by quadrat method.
3.
Study the plant population frequency by quadrat method.
4.
Prepare a temporary mount of onion root tip to study mitosis.
5.
Isolate DNA from available plant material such as spinach, green pea seeds, papaya, banana etc.
B. Study and observe the following (Spotting):
1.
Flowers adapted to pollination by different agencies (wind, insects, birds).
2.
Pollen germination on stigma through a permanent slide or scanning electron micrograph.
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, widow’s peak and colour blindness.
8.
Controlled pollination – emasculation, tagging and bagging.
9.
Common disease causing organisms like Ascaris, Entamoeba, Plasmodium, any fungus causing ringworm through permanent slides, models or virtual images or specimens. Comment on symptoms of diseases that they cause.
10.
Models specimens showing symbiotic association in lichens, root nodules of leguminous plants, and parasitic mode of nutrition shown by Cuscuta on host.
11.
Flash cards / models showing examples of homologous and analogous organs.
Practical Examination for Visually Impaired Students of Classes XI and XII Evaluation Scheme
Time: 02 Hours
Max. Marks: 30
Topic
Marks
Identification/Familiarity with the apparatus
5
Written test (Based on given / prescribed practicals)
10
Practical Records
5
Viva
10
Total
30
General Guidelines
•
The practical examination will be of two-hour duration. A separate list of ten experiments is included here.
•
The written examination in practicals for these students will be conducted at the time of practical examination of all other students.
•
The written test will be of 30 minutes duration.
•
The question paper given to the students should be legibly typed. It should contain a total of 15 practical skill based very short answer type questions. A student would be required to answer any 10 questions.
•
A writer may be allowed to such students as per CBSE examination rules.
•
All questions included in the question paper should be related to the listed practicals. Every question should require about two minutes to be answered.
•
These students are also required to maintain a practical file. A student is expected to record at least five of the listed experiments as per the specific instructions for each subject. These practicals should be duly checked and signed by the internal examiner.
•
The format of writing any experiment in the practical file should include aim, apparatus required, simple theory, procedure, related practical skills, precautions etc.
•
Questions may be generated jointly by the external/internal examiners and used for assessment.
•
The viva questions may include questions based on basic theory / principle / concept, apparatus / materials / chemicals required, procedure, precautions, sources of error etc.
Class XII
A.
Items for Identification/ familiarity with the apparatus for assessment in practicals (All experiments) Beaker, flask, petriplates, soil from different sites – sandy, clayey, loamy, small potted plants, aluminium foil, paint brush, test tubes, starch solution, iodine, ice cubes, Bunsen burner/spirit lamp/water bath, large flowers, Maize inflorescence, model of developmental stages highlighting morula and blastula of frog, beads/seeds of different shapes/size/texture Ascaris, Cactus/Opuntia (model).
B.
List of Practicals
1.
Study of flowers adapted to pollination by different agencies (wind, insects).
2.
Identification of T.S of morula or blastula of frog (Model).
3.
Study of Mendelian inheritance pattern using beads/seeds of different sizes/texture.
4.
Preparation of pedigree charts of genetic traits such as rolling of tongue, colour blindness.
5.
Study of emasculation, tagging and bagging by trying out an exercise on controlled pollination.
6.
Identify common disease causing organisms like Ascaris (model) and learn some common symptoms of the disease that they cause.
7.
Comment upon the morphological adaptations of plants found in xerophytic conditions.
Note: The above practicals may be carried out in an experiential manner rather than recording observations.
Prescribed Books:
1.
Biology, Class-XII, Published by NCERT.
2.
Other related books and manuals brought out by NCERT (includes multimedia).
3.
Biology Supplementary Material (Revised). Available on CBSE website.
4.
Reading Material Biology Class XII.
Question Paper Design (Theory)
Competencies
Total
Demonstrate Knowledge and Understanding
50%
Applicaiton of Knowledge / Concepts
30%
Analysis, Evaluate and Create
20%
Note:
•
Typology of questions: VSA including MCQs, Assertion – Reasoning type questions; SA; LA-I; LA-II; Source-based/ Case-based/ Passage-based/ Integrated assessment questions.
•
An internal choice of approximately 33% would be provided.
Suggestive verbs for various competencies
•
Demonstrate, Knowledge and Understanding:
State, name, list, identify, define, suggest, describe, outline, summarize, etc.
•
Application of Knowledge/Concepts:
Calculate, illustrate, show, adapt, explain, distinguish, etc.
•
Analyze, Evaluate and Create:
Interpret, analyse, compare, contrast, examine, evaluate, discuss, construct, etc.