NCERT Solutions class 12 Biology PDF
Solutions for other subjects Physics, Chemistry, Maths are also available to download. Download sample papers and Previous Years CBSE board papers as per latest CBSE Syllabus for 2019 for more practice of subjects. Download all chapters in PDF format available in NCERT solutions sections of each subject.
Chapter 1: Reproduction in Organisms
Chapter 2: Sexual Reproduction in Flowering Plants
Chapter 3: Human Reproduction
Chapter 4: Reproductive Health
Chapter 5: Principle of Inheritance and Variation
Chapter 6: Molecular Basis of Inheritance
Chapter 7: Evolution
Chapter 8: Human Health and Diseases
Chapter 10: Microbes in Human Welfare
Chapter 11: Biotechnology: Principles and Processes
Chapter 12: Biotechnology and its Applications
Chapter 13: Organisms and Populations
Chapter 14: Ecosystem
Chapter 15: Biodiversity and Conservation
Chapter 16: Environmental Issues
- NCERT Solutions for class 12 Chemistry
- NCERT Solutions for class 12 Maths
- NCERT Solutions for class 12 Physics
- NCERT Solutions for class 12 Physical Education
- NCERT Solutions for class 12 Business Studies
- NCERT Exemplar Problems Solutions for class 12 Physics
- NCERT Exemplar Problems Solutions for class 12 Chemistry
- NCERT Exemplar Problems Solutions for class 12 Biology
- NCERT Exemplar Problems Solutions for class 12 Maths
Main Point to Ponder
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).
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 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-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 and rice genome projects; DNA fingerprinting.
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.
Chapter-8: Human Health and Diseases
Pathogens; parasites causing human diseases (malaria, dengue, chickengunia, 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
Improvement in food production: Plant breeding, tissue culture, single cell protein, Biofortification, Apiculture and Animal husbandry.
Chapter-10: Microbes in Human Welfare
In household food processing, industrial production, sewage treatment, energy generation and microbes as biocontrol agents and biofertilizers. Antibiotics; production and judicious use.
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, bio piracy and patents.
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.
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
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).