NCERT Solutions for Class 12 Biology

NCERT Solutions for Class 12 Biology in Hindi and English all chapters are given here. NCERT Solutions 2024-25 for other subjects also available to download. Get the latest sample papers and Previous Years CBSE board papers as per latest CBSE Syllabus for biology. Download all chapters in PDF format available in NCERT solutions sections of each subject.

Chapter 1: Sexual Reproduction in Flowering Plants
Class 12 Biology chapter 1 brief us about Flower structure like development of male and female gametophytes. We learn about pollination including types, agencies and examples. Get an overview about outbreeding devices like pollen-pistil, interaction and double fertilization. In post fertilization events we will study about development of endosperm and embryo along with development of seed and formation of fruit. Chapter 1 of 12th Biology deals with Special modes-apomixis, parthenocarpy, and polyembryony. Significance of seed dispersal and fruit formation is the last topic the chapter.

Chapter 2: Human Reproduction
Class 12 Biology chapter 2 gives an overview about Male and female reproductive systems along with microscopic anatomy of testis and ovary. Here we will study about gametogenesis including spermatogenesis and oogenesis. The main topics are menstrual cycle, fertilisation, embryo development upto blastocyst formation, and implantation. Later on this chapter describes abotu pregnancy and placenta formation (elementary idea) including parturition and lactation (elementary idea).

Chapter 3: Reproductive Health
In chapter 3, we learn about the needs for reproductive health and prevention of Sexually Transmitted Diseases (STDs). Main topics includes the birth control need and methods, contraception and medical termination of pregnancy (MTP). Student will about amniocentesis along with infertility and assisted reproductive technologies like IVF, ZIFT, GIFT (elementary idea for general awareness).

Chapter 4: Principles of Inheritance and Variation
The first topic Heredity and variation includes Mendelian inheritance. Here we will learn about deviations from Mendelism like incomplete dominance, co-dominance, multiple alleles and inheritance of blood groups. In pleiotropy we explore the elementary idea of polygenic inheritance and chromosome theory of inheritance. The study of chromosomes and genes help us in Sex determination in humans, birds and honey bee. Chapter 4 of 12th Biology also explains about linkage and crossing over with sex linked inheritance like haemophilia, and colour blindness. The last topic in chapter 4 is Mendelian disorders in humans. This chapter explains about chromosomal disorders in humans, Down’s syndrome, Turner’s and Klinefelter’s syndromes.

Chapter 5: Molecular Basis of Inheritance
Get a complete search for genetic material and DNA as genetic material in chapter 5. We will learn here about the structure of DNA and RNA with DNA packaging and replication. The main topics of the chapters are Central dogma, transcription, genetic code, translation, gene expression and regulation.

Chapter 6: Evolution
In Chapter 6 of class 12 Biology, students will learn about Origin of life with biological evolution. It helps to know the evidences for biological evolution (paleontology, comparative anatomy, embryology and molecular evidences). The other topics for this chapters are Darwin’s contribution, modern synthetic theory of evolution. The mechanism of evolution includes variation (mutation and recombination) and natural selection with examples. Learn here the types of natural selection, Gene flow and genetic drift. Hardy – Weinberg’s principle, adaptive radiation and human evolution are very important.

Chapter 7: Human Health and Diseases
Learn about Pathogens, parasites causing human diseases like malaria, dengue, chickengunia, filariasis, and ascariasis. The other useful topics are typhoid, pneumonia, common cold, amoebiasis, ring worm and their control. Learn the Basic concepts of immunology like vaccines, cancer, HIV and AIDS. The last topic of the chapter is Adolescence with drug and alcohol abuse.

Chapter 8: Microbes in Human Welfare
This chapter deals with household food processing, industrial production, sewage treatment, energy generation and microbes. These are as biocontrol agents and biofertilizers. The other topics are Antibiotics, production and judicious use.

Chapter 9: Biotechnology – Principles and processes
This chapter teaches us about Genetic Engineering like Recombinant DNA Technology.

Chapter 10: Biotechnology and its Application
Learn here about Application of biotechnology in health and agriculture. The other important topics are Human insulin and vaccine production including stem cell technology, and gene therapy. Students will learn about the genetically modified organisms and Bt crops. The chapter also deals with transgenic animals, bio-safety issues, bio piracy and patents.

Chapter 11: Organisms and Populations
In class 12 Biology, we study about Organisms and environment including Habitat and niche, population and ecological adaptations. We also know about population interactions like mutualism, competition, predation, and parasitism. Students should know about Population attributes as growth, birth rate and death rate, age distribution.

Chapter 12: Ecosystem
Student will learn about Ecosystems Patterns, and components. Chapter 12 of 12 Biology also deals with productivity and decomposition with energy flow. It explains the pyramids of number, biomass, energy and nutrient cycles (carbon and phosphorous). Learn about ecological succession; ecological services like carbon fixation, pollination, seed dispersal, oxygen release (in brief).

Chapter 13: Biodiversity and its Conservation
12th Biology chapter 13 describes about Concept of biodiversity and its patterns along with importance or loss of biodiversity. We should come forward for Biodiversity conservation and to identify the hotshots. We have to take care of endangered organisms or extinction. Here we will study about Red Data Book, biosphere reserves, national parks, sanctuaries and Ramsar sites.