CBSE class 12 Biology new syllabus 2021-22

Higher secondary is the most crucial stage
of education because at this juncture specialized disciplines of science are introduced. The present syllabus reinforces the concepts introduced in lower classes. Recently, the science of biology has undergone a paradigm shift that has transformed it from a collection
of loosely related facts into a modern applied science.

Living organisms exhibit extremely
complex functional system. Organisms seldom occur as isolated individuals. They are organized into populations and biological communities. Organisms, communities, ecosystems and environment constitute unique set of natural resources of great importance.


Knowledge of biology helps us to
understand a common thread which holds all these components together. Understanding of biology will help in the sustainable development of the environment and will also ensure the
existence of earth with all its amazing diversity.

This CBSE class 12 syllabus is designed to prepare students for various examinations conducted at state and national level. Hence it has been prepared in accordance with the guidelines shown in the final version of common core syllabi of COBSE, Delhi. Accordingly some additional topics from state Board syllabus have been deleted whereas the lacking topics have been added. The entire unit “Ecology and
Environment” has now been added under
Botany and Zoology sections.

The present CBSE class 12 syllabus provides the students with new concepts along with an extended exposure to contemporary areas of the subject. The syllabus also aims at emphasizing on the underlying principles that are common to both animals and plants as well as highlighting the relationship of Biology with other
areas of knowledge. The format of the syllabus allows a simple, clear, sequential flow of concepts. It relates the study of biology to real life through the use of technology. It links the discoveries and
innovations in biology to everyday life such as environment, industry, health and agriculture. The updated syllabus of class 12 also focuses on reducing the curriculum load while ensuring that ample opportunities .and scope for learning and appreciating basic concepts of the subject continue to be available within its framework.


Objectives
The prescribed syllabus is expected to
  1. Promote the inherent skill of observation.
  2. Assist to understand the underlying principles of biological sciences and thereby develop scientific attitude towards biological phenomena.
  3. Help students to understand the functioning of organisms.
  4. Make students aware of issues of global importance.
  5. Guide students to perform easy experiments for better understanding of biological principles and to develop experimental skills required in practical work.
  6. Create awareness about the contribution of biology to human welfare.


Unit-VI Reproduction
Chapter-1: Reproduction in Organisms
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.

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 formation.

Chapter-3: 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-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
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 - haemophilia, colour 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.

Chapter-7: 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-8: 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-9: Strategies for Enhancement in Food Production 
Animal husbandry, Plant breeding, tissue culture, single cell protein.

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.

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.


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-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-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.

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; case study exemplifying success story addressing environmental issue(s).


A. List of Experiments (60 Periods)
1. Prepare a temporary mount to observe pollen germination.

2. 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 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 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 colourblindness.

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. 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 for Class 12 CBSE Board

Chapter 1 NCERT Solutions class 12th Biology Chapter 1 Reproduction in Organisms

Chapter 2 :  NCERT Solutions class 12th Biology Chapter 2 Reproduction in flowering plant

Chapter 3 : NCERT Solutions class 12th Biology Chapter 3 Human Reproduction

Chapter 4 : NCERT Solutions Class 12th Biology chapter 4 Reproductive Health

Chapter 5 : NCERT Solutions class 12th biology chapter 5 Principle of inheritance and veriation

Chapter 6 :  NCERT Solutions class 12th biology chapter 6 Molecular Basis of Inheritance