CBSE Class 12 Biology Syllabus 2020-21 (Revised) | Download New Syllabus PDF

CBSE Class 12 Biology Syllabus

CBSE Class 12 Biology Syllabus 2020-21: Biology is one of the most important subjects for CBSE Class 12 Board Exams, as this helps in the preparation of NEET too. CBSE Class 12 Biology Syllabus helps us to know about the important topics and overview of the subject.

If you are preparing for the Class 12 Biology Exam and in search of the latest CBSE Syllabus for Class 12, then Don’t worry! you are landed in the right place. Here, in this article on CBSE Class 12 Biology Syllabus.

You can easily check the CBSE Class 12 Biology syllabus and download PDF from the article below.

Latest CBSE Class 12 Biology Syllabus 2020-21 PDF

Biology is an important subject for CBSE Science Stream. It is an essential subject for those students who want to pursue a Medical, Biotechnology, Biomedical Engineering, etc. degree.

You should have an in-depth concept about the CBSE Class 12 Biology Syllabus to score better marks in the CBSE 12th Board exam. As with better clearance of concepts of the latest syllabus, you can secure good marks.

You already know CBSE updates about CBSE Class 12 Syllabus and Exam pattern, almost every year there will be a slight change in the paper pattern and syllabus. Here you can check CBSE new exam pattern for the Class 12 Biology and Marking Scheme

Download CBSE Class 12 Biology Syllabus PDF

Revised CBSE Class 12 Biology Syllabus (After 30% Reduction)

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NEW CBSE Class 12 Biology Syllabus 2020-21

CBSE Class 12 Biology Syllabus 2020-21 Unit-VI Reproduction

Chapter-2: Sexual Reproduction in Flowering Plants

  • Flower structure; development of male and female gametophytes; pollination – types, agencies, and examples; outbreeding 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

Chapter-3: Human Reproduction

  • Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis – spermatogenesis and oogenesis; menstrual cycle; fertilization, embryo development up to 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).

CBSE Class 12 Biology Syllabus 2020-21 Unit-VII Genetics and Evolution

Chapter-5: 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 human being, birds, and honey bee; linkage and crossing over; sex-linked inheritance – hemophilia, color blindness; Mendelian disorders 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, Human and rice genome projects; DNA fingerprinting.

CBSE Class 12 Biology Syllabus 2020-21 Unit-VIII Biology and Human Welfare

Chapter-8: Human Health and Diseases

  • 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.

Chapter-10: 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.

CBSE Class 12 Biology Syllabus 2020-21 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, stem cell technology, gene therapy; genetically modified organisms – Bt crops; transgenic animals; biosafety issues, biopiracy, and patents.

CBSE Class 12 Biology Syllabus 2020-21 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 attributes – growth, birth rate, and death rate, age distribution.

Chapter-15: 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.

CBSE Class 12 Biology Syllabus 2020-21 CBSE 12th Biology Practical Syllabus

List of Experiments

  • Prepare a temporary mount to observe pollen
  • Collect and study soil 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
  • Collect water from two different water bodies around you and study them for pH, clarity, and presence of any living
  • Prepare a temporary mount of the onion root tip to study
  • Study the effect of different temperatures or three different pH on the activity of salivary amylase on
  • Isolate DNA from available plant material such as spinach, green pea seeds, papaya,

Study/observation of the following (Spotting)

  • Flowers adapted to pollination by different agencies (wind, insects, birds).
  • Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary through permanent slides (from grasshopper/mice).
  • Meiosis in onion bud cell or grasshopper testis through permanent
  • S. of blastula through permanent slides (Mammalian).
  • Prepared pedigree charts of any one of the genetic traits such as rolling of tongue, blood groups, ear lobes, widow’s peak, and color
  • Common disease-causing organisms like Ascaris, Entamoeba, Plasmodium, any fungus causing ringworm through permanent slides, models, or virtual images. Comment on symptoms of diseases that they
  • Two plants and two animals (models/virtual images) found in xeric conditions. Comment upon their morphological adaptations.
  • Two plants and two animals (models/virtual images) found in aquatic conditions. Comment upon their morphological

Deleted CBSE 12th Biology Syllabus 2020-21 PDF

CBSE Class 12 Biology Syllabus 2020-21 Unit-VI Reproduction

Chapter-1: Reproduction in Organism

  • Reproduction, a characteristic feature of all organisms for continuation of species; Modes of reproduction – asexual and sexual reproduction; asexual reproduction – binary fission, sporulation, budding, gemmule formation, fragmentation; vegetative propagation in plants.

CBSE Class 12 Biology Syllabus 2020-21 Unit-VII Genetics and Evolution

Chapter-7: Evolution

  • Origin of life; biological evolution and evidence for biological evolution (paleontology, comparative anatomy, embryology, and molecular evidence); Darwin’s contribution, the 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.

CBSE Class 12 Biology Syllabus 2020-21 Unit-VIII Biology and Human Welfare

Chapter 9: Strategies for Enhancement in Food Production

  • Animal husbandry, Plant breeding, tissue culture, single-cell protein.

CBSE Class 12 Biology Syllabus 2020-21 Under Unit-X Ecology and Environment

Chapter-14: Ecosystem

  • Ecosystems: 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 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 impact and mitigation; ozone layer depletion; deforestation; exemplifying case study as success story addressing the environmental issue(s).

CBSE 12th Biology Practical Syllabus 2020-21(Deleted)

Here you can check the deleted CBSE Class 12 Biology Syllabus 2020-21 

 A: List of Experiments

  • Study the presence of suspended particulate matter in air at two widely different sites.
  • Study the plant population density by quadrat method.
  • Study the plant population frequency by quadrat method.

B. Study/Observer of the following (spotting)

  • Pollen germination on stigma through a permanent slide or scanning electron micrograph.
  • Mendelian inheritance using seeds of different colors/sizes of any plant.
  • Controlled pollination – emasculation, tagging, and bagging.

CBSE Class 12 Biology Exam Pattern 2020-21 & Marking Scheme

Class 12 Biology Exam patten Comprises of both theory and Practical marks

  • Theoretical Paper: 70 marks
  • Practical/ Project Work: 30 Marks

CBSE Class 12 Biology Question Paper Pattern 2020-21:

Time Duration

3 Hours

Maximum Marks

70 marks

Total No. of Questions


Type of Questions

Very Short Answer – 2 marks

Short Answer I – 2 marks

Short Answer II – 3 marks

Long Answer I – 5 marks

 CBSE 12th Biology Marking Scheme 2020-21

Download Class 12 Biology marking Scheme for Better preparation and Score Good Marks 

Click Here to download Class 12 Marking Scheme 2020-21








Genetics and Evolution



Biology and Human Welfare



Biotechnology and its Applications



Ecology and Environment 




CBSE Class 12 Biology Practical Exam Pattern 2020-21

In 12th Biology, Practical exams play an important role, Here is the Detailed Syllabus and Exam pattern for Practicals. The total time allowed for the Practical exam is 3 hours for 30 marks.

Evaluation Scheme Marks
One Major Experiment Part A (Experiment No- 1,3,7,8) 5 Marks
One Minor Experiment Part A (Experiment No- 6,9,10,11,12,13) 4 Marks
Slide Preparation Part A (Experiment No- 2,4,5) 5 Marks
Spotting Part B 7 Marks
Practical Record + Viva Voce 4 Marks
Practical Record + Viva Voce 5 Marks
Total 30 Marks

NCERT Biology Class 12 Textbooks PDF 2020-21

The Biology book covers topics like Reproduction in Organisms, Human Reproduction, Sexual Reproduction in Flowering Plants, etc.

The book is specially created to provide a depth concept on the subject and also helps to prepare for various entrance exams.

The book is specifically focused on living Organisms, Evolution, and Biotech. While, for Human Ecology, there is a separate book.

Here you can download Chapter-wise NCERT Textbook for Class 12 Biology for Hindi and English Medium.

Download Chapter-Wise NCERT Class 12 Biology Textbooks PDF 2020-21 For English Medium

Here we are providing the chapter-wise NCERT Class 12 Biology Textbooks PDF. You can read it online or download it easily.

Unit VI Reproduction 

Unit VII Genetics and Evolution 

Unit VIII Biology in Human Welfare 

Unit IX Biotechnology 

Unit X Ecology 

Download Chapter-Wise NCERT Biology Class 12 2020-21 PDF For Hindi Medium

Here we are providing the chapter-wise NCERT Class 12 Biology Textbooks PDF 2020. You can read it online or download it easily.

इकाई छः जनन

इकाई सात: आनुवंशिकी तथा विकास

इकाई आठ: मानव कल्याण में जीव विज्ञान

इकाई नौ: जैव प्रौद्योगिकी

इकाई दस: पारिस्थितिकी

Highly Important Links Related To CBSE Class 12

CBSE NCERT Class 12 Book For All Subjects. NCERT Solutions For Class 12
CBSE 12th Sample Papers 2020-21 Class 12th Previous Year Papers
CBSE 12th Grading System CBSE 12th Study Plan To Score High
CBSE 12th Date Sheet 2020-21 CBSE 12th Admit Card 2020-21
CBSE 12th Practical Exam 2020-21 CBSE 12th Result 2020-21

How to Download CBSE Class 12 Biology Syllabus 2020-21 from the Official Website?

Follow the steps given below to download the CBSE 12th syllabus for Biology 2020-21 from the official website:

  • Step 1 Go to the official website,
  • Step 2 – On the home page, click on the ‘Curriculum’ option.
  • Step 3 – Click on the ‘Senior Secondary Curriculum (XI-XII)’.
  • Step 4 – Select Academic Electives – (Group-A).
  • Step 5 – Now click on the Biology tab. The CBSE Class 12 Biology Syllabus 2020-21 will get displayed on your screens. Save the syllabus in pdf format.

We have covered the detailed guide on Revised CBSE Class 12 Biology Syllabus 2020-21. Feel free to ask any questions related to Class 12 Biology in the comment section below.

Is NCERT book enough to prepare for the exams?

Yes, NCERT books are enough to prepare for the exams and cover CBSE class 12 Biology syllabus 2020-21.

Is this CBSE 12th syllabus 2020-21 latest?

Yes, this syllabus is the latest syllabus, as released by CBSE after reduction.

What are the passing marks in CBSE Class 12th exams?

Students must score at least 33 per cent marks per subject in order to pass the CBSE Class 12 exams.

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