NCERT Solutions for Class 12 Biology 2024-25 - Pdf Download

Biology may seem like a straightforward subject but sometimes it can be challenging. NCERT has a curriculum for schools that follow CBSE's guidelines. We've listed NCERT solutions below to help you answer the questions correctly, using a logical and methodical approach. The solutions provide enough material to help you get a good start with the basics of the subject.

NCERT textbooks are considered as more than sufficient, without the need for other refreshers. Solutions are prepared keeping the language and simplicity of the explanations in NCERT textbooks in mind. NCERT textbooks not only prepare for the board and school exams, but also play a crucial role in entrance exams like JEE and NEET.

Class 12 Biology NCERT Solutions

Several fundamental concepts such as Reproduction, Inheritance, Evolution, Food Production, Biotechnology, Ecosystem, Biodiversity, etc. are precisely explained in the NCERT Class 12 Biology textbook with well-structured diagrams for better understanding of teachers and students so that their fundamental concepts are well-understood from the very beginning and thus helps them in getting good marks in the board exams.

NCERT Solutions for Class 12 Biology Chapter List

Chapter list of class 12 biology is given below: 

The chapters listed below have been deleted from the Class 12 Biology NCERT Biology Textbook 2023 - 24.

• Reproduction in Organisms

• Strategies for Enhancement in Food Production

• Environmental Issues

NCERT Solutions for Class 12 Biology Chapter Details

Class 12 Biology Chapter 1 Sexual Reproduction in Flowering Plants

Sexual reproduction in flowering plants describes the morphology, structuring and reproductive processes of angiospermia. It also covers subtopics like pre-fertility: Structure and events, double fertilisation, post-fertility: structure and events, apomixis, and polyembryony.

Topics covered in Class 12 NCERT Biology Chapter 1 Sexual Reproduction in Flowering Plants

• Flower structure

• Development of male and female gametophytes

• Pollination – types, agencies and examples

• Out breeding devices

• Pollen-pistil interaction

• Double fertilisation

• Post-fertilisation 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

Class 12 Biology Chapter 2 Human Reproduction 

In humans, reproductive events involve creating gametes, which are sperm in males and ovum in females. After reaching a certain age, human become sexually active which is called puberty and there are some big differences between male and female when it comes to reproductive events. This chapter will look at the reproductive systems of male and female in humans. You will learn about the male system, female system, and gametogenesis. They'll also learn about the menstrual cycle and how it works, how it's fertilised and implanted, how it develops during pregnancy and egg production.

Topics covered in Class 12 NCERT Biology Chapter 2 Human Reproduction

• Male and female reproductive systems

• Microscopic anatomy of testis and ovary

• Gametogenesis – spermatogenesis and oogenesis

• Menstrual cycle

• Fertilisation

• Embryo development up to blastocyst formation

• Implantation

• Pregnancy and placenta formation (elementary idea)

• Parturition (elementary idea)

• Lactation (elementary idea)

Class 12 Biology Chapter 3 Reproductive Health

The topic of reproductive health is closely related to other topics discussed in this chapter. Reproductive health is the health of reproductive organs and their normal functioning. According to WHO, reproductive health is the complete well-being of reproductive organs in all stages of reproduction (physical, emotional, behavioral and social). Subtopics of reproductive health include reproductive health – problems and strategies, population explosion and birth control, medical termination of pregnancy, sexually transmitted diseases, and infertility.

Topics covered in Class 12 NCERT Biology Chapter 3 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).

Class 12 Biology Chapter 4 Principle of Inheritance and Variation

Genetics is the branch of Biology concerned with inheritance and variation of characters. Inheritance refers to the transfer of characters from parents to offspring. It is the foundation of inheritance. Variation refers to the degree to which the child differs from its parent. This chapter includes subtopics like Mendel's laws of inheritance, inheritance of one gene, inheritance of two genes, sex determination, mutation, and genetic disorders.

Topics covered in Class 12 NCERT Biology Chapter 4 Principle 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.

Class 12 Biology Chapter 5 Molecular Basis of Inheritance

In the previous chapter, you have learned about inheritance patterns and their genetic basis. Back in Mendel’s time, it wasn’t clear what those factors were that governed the inheritance pattern. Over the course of the next century, scientists began to study the genetic material that was supposed to be the genetic material. Eventually, they discovered that the genetic material for most organisms was DNA. Subtopics of this chapter includes DNA, the search for Genetic Material, RNA World, Replication, Transcription, Genetic Code, Translation, Human Genome Project and DNA Fingerprinting.

Topics covered in Class 12 NCERT Biology Chapter 5 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

Class 12 Biology Chapter 6 Evolution 

The field of Evolutionary Biology is concerned with the evolutionary history of life on earth. Subtopics covered in this chapter includes Origin of life, Theory of the Evolution of life Forms, Adaptive Radiation, Biological Evolution, Mechanism of Evolution, Hardy-Weinberg Principle, A Brief Account of Evolution, Origin and Evolution of Man in relation to Evolution.

Topics covered in Class 12 NCERT Biology Chapter 6 Evolution 

• Origin of life

• Biological evolution and evidence for biological evolution (comparative anatomy, embryology and molecular evidence)

• 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

Class 12 Biology Chapter 7 Human Health and Diseases

For many years, health has been associated with a state of balance between the body and mind. This balance is affected by a variety of factors including genetic disorders – deficiencies that a child is born with or inherited from the parents from birth, infections and lifestyle factors such as the type of food and water consumed, the amount of rest and exercise given to the body and any habits that are present or absent. This chapter also covers subtopics such as Common Diseases in Humans, Immunity, AIDS, Cancer, Drugs, and Alcohol Abuse.

Topics covered in Class 12 NCERT Biology Chapter 7 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

Class 12 Biology Chapter 8 Microbes in Human Welfare

In addition to the macroscopic plant and animal systems, microbes are the main building blocks of biological systems on earth. You have explored the variety of diversity organisms in class XI. Microbes include protozoa, bacteria, fungi, animal and plant viruses and viroids, as well as proteinaceous infectious agents such as prions. Bacteria and many fungi can grow on nutritive media and form colonies that are visible to the naked eye. These cultures are useful for micro-organism studies. Microbes can be used in a variety of ways, like in household products, industrial products, sewage treatment, biogas production, as biocontrol agents, and as biofertilisers.

Topics covered in Class 12 NCERT Biology Chapter 8 Microbes in Human Welfare

• Microbes in food processing

• industrial production

• sewage treatment

• energy generation and microbes as bio-control agents and bio-fertilisers. 

• Antibiotics: production and judicious use

Class 12 Biology Chapter 9 Biotechnology Principles and Processes

Biotechnology refers to the process of using living organisms or enzymes from living organisms to create products and processes that can be used to benefit humans. The definition of biotechnology by EFB (European Federation of Biotechnology) covers traditional biotechnology and molecular biotechnology. EFB defines biotechnology as ‘The integration of natural science with organisms, cells, molecular analogues, for the production of products and services’. Subtopics mentioned in this chapter include Biotechnology principles, tools of recombinant DNA technology and processes of recombinant DNA technology.

Topics covered in Class 12 NCERT Biology Chapter 9 Biotechnology Principles and Processes

• Genetic Engineering

Class 12 Biology Chapter 10 Biotechnology and Its Application

You woul have learned from the previous chapter that biotechnology is concerned with the production of bio-medicines and biologicals on an industrial scale using genetically modified microorganisms, fungi, plants and animals. Examples of biotechnological applications include therapeutic drugs, diagnostic tests, processed foods, bioremediation, waste treatment and energy generation. This chapter also covers topics such as biotechnological application in agriculture, medicine, transgenic animals and ethical issues.

Topics covered in Class 12 NCERT Biology Chapter 10 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.

Class 12 Biology Chapter 11 Organisms and Populations

In your previous classes, you have been introduced to the concept of Ecology which is the study of the relationships between organisms and between organisms and their physical environment (abiotic). This chapter examines the four levels of bioregional organisation namely the organisms, populations, communities and  biomes.This chapter looks at Ecology at the level of organisms and populations. It also covers subtopics like organisms and their environment and populations. 

Topics covered in Class 12 NCERT Biology Chapter 11 Organisms and Populations

• Population interactions – mutualism, competition, predation, parasitism

• Population attributes – growth, birth rate and death rate, age distribution. 

(Topics excluded: Organism and its Environment, Major Abiotic Factors, Responses to Abiotic Factors, Adaptations)

Class 12 Biology Chapter 12 Ecosystem

An ecosystem can be conceptualised as a functional system in which living organisms interact with each other and with the physical environment. This chapter will first analyse the structure of an ecosystem to gain an understanding of the inputs (productivity), outputs (food chain, nutrient cycling), and relationships within the system (cycles, chains, webs) and their relationship to each other. Subtopics such as Ecosystem – Structure and Function, Productivity, Decomposition, Energy Flow, Ecological Pyramids, Ecological Succession, Nutrient Cycling and Ecosystem Services w ill also be discussed.

Topics covered in Class 12 NCERT Biology Chapter 12 Ecosystem

• Ecosystems: Patterns, components

• Productivity and decomposition

• Energy flow

• Pyramids of number, biomass, energy 

(Topics excluded: Ecological Succession and Nutrient Cycles)

Class 12 Biology Chapter 13 Biodiversity and Conservation

The field of biodiversity and conservation consist of topics such as genetic diversity, species diversity, ecological diversity, different types of species, patterns of diversity, loss of biodiversity, and biodiversity conservation. Conservation may be carried out both in situ and ex situ. In situ conservation involves the preservation of endangered species in their natural environment, thus safeguarding the entire ecosystem. Ex situ conservation methods include the protection of endangered species in zoological parks and botanical gardens, In vitro fertilization, propagation of tissue cultures and the conservation of genetically modified gametes.

Topics covered in Class 12 NCERT Biology Chapter 13 Biodiversity and 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.

Frequently Asked Questions

Question 1: Why are NCERT solutions are important for class 12 biology?

Answer 1: NCERT Solutions help you understand the questions in your textbook better. NCERT Solutions help you solve problems quickly and easily. NCERT Solutions provide accurate and structured explanations for questions in your textbook. NCERT solutions help you prepare for exams.

Question 2: Can NCERT Solutions help with last-minute revisions?

Answer 2: Yes, NCERT solutions can be useful during the last-minute revision process. NCERT solutions provide quick answers and clarifications to crucial questions, enabling you to quickly review and remember important concepts ahead of exams.