| Latest Science NCERT Notes and Solutions (Class 6th to 10th) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6th | 7th | 8th | 9th | 10th | ||||||||||
| Latest Science NCERT Notes and Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Latest Science NCERT Notes and Solutions (Class 12th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
Latest Class 12th Biology NCERT Concepts & Solutions
1. Sexual Reproduction In Flowering Plants
This chapter details the process of sexual reproduction in angiosperms, covering the structure of the flower (male and female reproductive organs), gametogenesis (formation of pollen and ovules), pollination (transfer of pollen), fertilisation (fusion of gametes), double fertilisation (a unique event in angiosperms), and the post-fertilisation events leading to the development of the embryo, endosperm, seed, and fruit. It also touches upon apomixis and polyembryony.
2. Human Reproduction
This chapter explores the complex process of human reproduction. It describes the male and female reproductive systems, including the formation of gametes (spermatogenesis and oogenesis). Fertilisation, implantation of the embryo in the uterus, and the different stages of embryonic development up to childbirth (parturition) are explained. Basic concepts of lactation and mammary gland structure are also discussed.
3. Reproductive Health
Reproductive health focuses on a state of physical, emotional, behavioral, and social well-being in all matters related to the reproductive system. This chapter discusses key issues like population growth and control strategies (including contraception), methods to prevent sexually transmitted infections (STIs), infertility and assisted reproductive technologies (ARTs like IVF, ZIFT, GIFT), and challenges faced in India concerning reproductive health awareness and services.
4. Principles Of Inheritance And Variation
This foundational genetics chapter introduces how traits are passed from one generation to the next, covering Mendel's experiments on pea plants and his Laws of Inheritance (Dominance, Segregation, Independent Assortment). It explores deviations from Mendelian principles, such as incomplete dominance and co-dominance. Chromosomal theory of inheritance, linkage, crossing over, sex determination mechanisms, and common genetic disorders like colour blindness and sickle-cell anaemia are also discussed.
5. Molecular Basis Of Inheritance
This chapter delves into the molecular mechanisms of heredity. It describes the structure of DNA and RNA, the genetic material. Processes like DNA replication (copying DNA), transcription (synthesizing RNA from DNA), and translation (synthesizing protein from RNA) are explained. The genetic code, gene regulation (e.g., lac operon), and the Human Genome Project are also covered, providing a detailed understanding of how genetic information is stored and expressed.
6. Evolution
This chapter explores the process by which life on Earth has changed over vast periods. It discusses theories on the origin of life, evidence for evolution from various fields (paleontology, comparative anatomy, embryology, molecular biology), Darwin's theory of natural selection, and mechanisms of evolution like mutation and genetic drift. Adaptive radiation and the evolutionary history of man are also examined, highlighting the gradual development of complex life forms.
7. Human Health And Disease
This chapter addresses common diseases affecting humans, their causative agents (pathogens like bacteria, viruses, fungi, protozoans, helminths), and modes of transmission. It explains the immune system, different types of immunity (innate and acquired), vaccination, and common ailments like malaria, typhoid, pneumonia, common cold, AIDS, and cancer. Concepts of allergy and the detrimental effects of drug and alcohol abuse are also covered.
8. Microbes In Human Welfare
Contrary to the focus on diseases, this chapter highlights the beneficial roles of microorganisms. It discusses their use in household products (curd, bread, idli, dosa), industrial production (antibiotics, beverages, organic acids, enzymes), sewage treatment, biogas production ($\textsf{CH}_4$), biocontrol agents (using microbes to control pests), and biofertilisers (enhancing soil fertility), showcasing the significant positive impact of microbes on human life and the environment.
9. Biotechnology : Principles And Processes
This foundational chapter introduces biotechnology as the use of living organisms or their parts to produce useful products or processes. It focuses on the core principles of genetic engineering, including the creation of recombinant DNA ($\textsf{rDNA}$). Key techniques and tools like restriction enzymes, cloning vectors, gene transfer methods, and downstream processing are explained, outlining the steps involved in manipulating genes for desired outcomes.
10. Biotechnology And Its Applications
Building on the principles, this chapter explores the wide-ranging applications of biotechnology in various fields. It discusses uses in agriculture (producing genetically modified crops for pest resistance or improved yield, e.g., Bt cotton), medicine (production of insulin, vaccines, gene therapy for genetic diseases, molecular diagnosis), and environmental sectors. Ethical considerations related to the use of biotechnology are also briefly addressed.
11. Organisms And Populations
This ecology chapter introduces the study of organisms and how they interact with their environment and with each other. It discusses the concept of ecology, organism-environment relationship, major abiotic factors (temperature, water, light, soil), and responses of organisms to these factors (regulation, conformation, migration, suspension). Population ecology focuses on population attributes (size, density, birth/death rates, age distribution) and interspecific interactions (mutualism, competition, predation, parasitism, commensalism, amensalism).
12. Ecosystem
An ecosystem is a structural and functional unit of nature comprising biotic and abiotic components interacting together. This chapter explores different types of ecosystems. It discusses ecosystem structure (species composition, stratification), functions (productivity, decomposition, energy flow through trophic levels, food chains, food webs), and nutrient cycling (biogeochemical cycles like carbon and phosphorus cycles). Concepts of ecological succession and ecosystem services are also introduced, highlighting the interconnectedness of nature.
13. Biodiversity And Conservation
Biodiversity refers to the variety of life forms on Earth at different levels (genetic, species, ecological). This chapter discusses patterns of biodiversity, its importance for ecosystem stability, and the major causes of biodiversity loss (habitat loss, overexploitation, alien species invasion, co-extinctions). The urgency of conservation is stressed, outlining methods like in-situ conservation (national parks, wildlife sanctuaries, biosphere reserves) and ex-situ conservation (zoos, botanical gardens, seed banks), including specific examples relevant to India like biodiversity hotspots.