CBSE Class 12 Biology Syllabus 2022-23 (updated) has been announced by the board wherein the term-wise system has been discontinued. As per the updated syllabus, total Theory weightage is 70 Marks and Practicals hold a weightage of 30 Marks. Check out a detailed report on updated Class 12 Syllabus 2022-23.

Students and teachers can check out the latest syllabus on cbseacademic.nic.in

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CBSE Class 12 Biology Syllabus Theory

CBSE Class 12 Biology Syllabus Theory examination focuses on understanding and application of scientific principles. Here is the syllabus and dedicated marks for all units covered in Class 12 Biology Theory Examination 2022-23.

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Class 12 Biology Syllabus Chapter-wise

Check out the detailed syllabus for Class 12 Biology Exams 2022-23 and important concepts covered:

Unit-VI Reproduction

Chapter-2: Sexual Reproduction in Flowering Plants

Important topics covered in this chapter are:

• 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

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Chapter-3: Human Reproduction

Important topics covered in this chapter are:

• Male and female reproductive systems 
• Microscopic anatomy of testis and ovary
• Gametogenesis- spermatogenesis and oogenesis; menstrual cycle 
• Fertilization, embryo development upto blastocyst formation, implantation 
• Pregnancy and placenta formation (elementary idea)
• Parturition (elementary idea) 
• Lactation (elementary idea)

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Chapter-4: Reproductive Health

Important topics covered in this chapter are:

• Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs) 
• Birth control- need and methods, contraception and medical termination of pregnancy (MTP)
• Infertility and assisted reproductive technologies- IVF, ZIFT, GIFT (elementary idea for general awareness)

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Unit-VII Genetics and Evolution

Chapter-5: Principles of Inheritance and Variation

Important topics covered in Principles of Inheritance and Variation are:

• 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

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Chapter-6: Molecular Basis of Inheritance

Important topics covered in Molecular Basis of Inheritance are:

• 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 8 expression and regulation- lac operon 
• Genome, Human genome project and rice genome projects 

• DNA fingerprinting

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Chapter-7: Evolution

Important topics covered in Evolution are:

• 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

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Unit-VIII Biology and Human Welfare

Chapter-8: Human Health and Diseases

Important topics covered in Human Health and Diseases are:

• 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

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Chapter-10: Microbes in Human Welfare

Important topics covered in this chapter are:

• Microbes in food processing, industrial production, sewage treatment, energy generation
• And microbes as bio-control agents and bio-fertilizers 
• Antibiotics- Production and judicious use

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Unit-IX Biotechnology and its Applications

Chapter-11: Biotechnology- Principles and Processes

Important topic covered in this chapter is:

Genetic Engineering (Recombinant DNA Technology)

Chapter-12: Biotechnology and its Applications

Important topics covered in this chapter are:

• 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

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Unit-X Ecology and Environment

Chapter-13: Organisms and Populations

Important topics covered in this chapter are:

• Population interactions- mutualism, competition, predation, parasitism 
• Population attributes- growth, birth rate and death rate, age distribution

Please note the excluded topics: Organism and its Environment, Major Abiotic Factors, Responses to Abiotic Factors, Adaptations

Chapter-14: Ecosystem

Important topics covered in this chapter are:

• Ecosystems: Patterns, components 
• Productivity and decomposition 
• Energy flow 
• Pyramids of number, biomass, energy 

Please note the excluded topics: Ecological Succession and Nutrient Cycles

Chapter-15: Biodiversity and its Conservation

Important topics covered in this chapter are:

• 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

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Class 12 Biology Syllabus: Practical Exams 2022-23

Class 12 Biology Syllabus Practical Exams 2022-23 Evaluation Scheme and Marks are specified below:

Note: Credit to the students’ work over the academic session may be given.

Part 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, etc.

Part 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

1. Models specimen showing symbolic association in root modules of leguminous plants, Cuscuta on host, lichens.
2. Flash cards models showing examples of homologous and analogous organs.

Practical Examination for Visually Impaired Students of Class XII Evaluation Scheme

Practical Examination for Visually Impaired Students of Class XII Evaluation Scheme is as follows:

General Guidelines

• The practical examination will be of two hour duration. 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.
• Viva questions may include questions based on basic theory/principle/concept, apparatus/materials/chemicals required, procedure, precautions, sources of error etc.

Class XII

1. Items for Identification/ familiarity with the apparatus for assessment in practicals (All experiments) Beaker, flask, petri plates, soil from different sites - sandy, clayey, loamy, small potted plants, aluminum 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)
2. 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.

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