NCERT Solutions For Class 12 Biology

Download Chapter-wise NCERT Solutions for Class 12 Biology

NCERT Solutions for Class 12 Biology help students to learn concepts from the CBSE syllabus easily. Furthermore, Biology NCERT Solutions Class 12 is prepared by experienced faculty members and academic professionals. Therefore, students have access to more resources than other similar websites. Moreover, we emphasise understanding the conceptual basis of CBSE Biology subject so that students can comprehend it with ease.

The topics covered in the Class 12 NCERT syllabus carry significant weightage for the competitive exams. Hence, we have compiled these solutions in a manner where students will be able to understand and recall the important topics with ease.

NCERT Solutions for Class 12 Biology Chapter-wise

Access and download NCERT Class 12 Books here.

NCERT Solutions Class 12 Biology Chapter Details and Exercises

Chapter 1: Reproduction in Organisms

The chapter Reproduction in Organisms explains how various organisms are able to procreate. Reproduction is an important biological process in which an organism gives rise to young ones similar to itself. There are two types of reproduction. When offspring is produced by a single parent with or without the involvement of gamete formation, reproduction is asexual. When two parents (opposite sex) participate in the reproductive process and involve the fusion of male and female gametes, it is called sexual reproduction. These concepts are elaborately explained with relevant diagrams and suitable examples.

Also, access the following resources for Class 12 Chapter 1 Reproduction in Organisms, at BYJU’S.

Chapter 2: Sexual Reproduction in Flowering Plants

Sexual Reproduction in Flowering Plants explains the morphology, structure and processes of sexual reproduction in angiosperms. It also elaborates on subtopics such as pre-fertilisation: Structure and Events, Double fertilisation, Post fertilisation: Structure and Events, Apomixis and Polyembryony.

Topics Covered in Class 12 CBSE Biology Chapter 2 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.

Also, access the following resources for Class 12 Chapter 2 Sexual Reproduction in Flowering Plants, at BYJU’S.

Chapter 3: Human Reproduction

Reproductive events in humans include the formation of gametes (gametogenesis), i.e., sperms in males and ovum in females. Humans reach sexual maturity after attaining a certain age; this is called puberty. There are remarkable differences between the reproductive events in the male and in the female. In this chapter, students will examine the male and female reproductive systems in humans. The subtopics covered in this chapter are the male reproductive system, the female reproductive system, gametogenesis, the menstrual cycle, fertilisation and implantation, pregnancy and embryonic development, parturition and lactation.

Topics Covered in Class 12 CBSE Biology Chapter 3 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).

Also, access the following resources for Class 12 Chapter 3 Human Reproduction, at BYJU’S.

Chapter 4: Reproductive Health

In the previous chapter, students have learnt about the human reproductive system and its functions. This chapter discusses a closely related topic – reproductive health. The term refers to healthy reproductive organs with normal functions. According to the World Health Organisation (WHO), reproductive health means total well-being in all the aspects of reproduction, i.e., physical, emotional, behavioural and social. It covers subtopics such as Reproductive health – Problems and Strategies, Population Explosion and Birth Control, Medical Termination of Pregnancy, Sexually Transmitted Diseases, and Infertility.

Topics Covered in Class 12 CBSE Biology 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).

Also, access the following resources for Class 12 Chapter 4 Reproductive Health, at BYJU’S.

Chapter 5: Principles of Inheritance and Variation

Genetics is a branch of Biology that deals with inheritance, as well as the variation of characters from parents to offspring. Inheritance is the process by which the characters are passed on from parent to progeny; it is the basis of heredity. Variation is the degree by which progeny differ from their parents. The chapter covers subtopics such as Mendel’s Laws of Inheritance, Inheritance of One Gene, Inheritance of Two Genes, Sex Determination, Mutation, and Genetic Disorders.

Topics Covered in Class 12 CBSE Biology 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.

Also, access the following resources for Class 12 Chapter 5 Principles of Inheritance and Variation, at BYJU’S.

Chapter 6: Molecular Basis of Inheritance

In the previous chapter, students have learnt the inheritance patterns and the genetic basis of such patterns. At the time of Mendel, the nature of those ‘factors’ regulating the pattern of inheritance was not clear. Over the next hundred years, the nature of the putative genetic material was investigated, culminating in the realisation that DNA – deoxyribonucleic acid – is the genetic material, at least for the majority of organisms. In Class XI, they have learnt that nucleic acids are polymers of nucleotides. It also includes subtopics such as DNA, the Search for Genetic Material, RNA World, Replication, Transcription, Genetic Code, Translation, Regulation of Gene Expression, Human Genome Project and DNA Fingerprinting.

Topics Covered in Class 12 CBSE Biology 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.

Also, access the following resources for Class 12 Chapter 6 Molecular Basis of Inheritance, at BYJU’S.

Chapter 7: Evolution

Evolutionary Biology is the study of the history of life forms on earth. It covers subtopics such as Origin of Life, Evolution of Life Forms – A Theory, What Are the Evidences for Evolution? What is Adaptive Radiation? Biological Evolution, Mechanism of Evolution, Hardy – Weinberg Principle, A Brief Account of Evolution, Origin and Evolution of Man related to Evolution, which is important for students to study.

Topics Covered in Class 12 CBSE Biology Chapter 7 Evolution

Origin of life; biological evolution and evidence for biological evolution (palaeontology, 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.

Also, access the following resources for Class 12 Chapter 7 Evolution, at BYJU’S.

Chapter 8: Human Health and Diseases

Health, for a long time, was considered a state of body and mind where there was a balance of certain humour. Health is affected by – (i) genetic disorders – deficiencies with which a child is born and deficiencies/defects which the child inherits from parents from birth; (ii) infections and (iii) lifestyle, including food and water we take, rest and exercise we give to our bodies, habits that we have or lack, etc. The chapter also includes subtopics such as Common Diseases in Humans, Immunity, AIDS, Cancer, Drugs and Alcohol Abuse.

Topics Covered in Class 12 CBSE Biology 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.

Also, access the following resources for Class 12 Chapter 8 Human Health and Diseases, at BYJU’S.

Chapter 9: Strategies for Enhancement in Food Production

With the ever-increasing population of the world, the enhancement of food production is a major necessity. Biological principles, as applied to animal husbandry and plant breeding, have a major role in our efforts to increase food production. Several new techniques, like embryo transfer technology and tissue culture techniques, are going to play a pivotal role in further enhancing food production. Subtopics that are explained in this chapter are Animal Husbandry, Plant Breeding, Single Cell Proteins and Tissue Culture.

Also, access the following resources for Class 12 Chapter 9 Strategies for Enhancement in Food Production, at BYJU’S.

Chapter 10: Microbes in Human Welfare

Besides macroscopic plants and animals, microbes are the major components of biological systems on this earth. Students have studied the diversity of living organisms in Class XI. Microbes are diverse-protozoa, bacteria, fungi and microscopic animal and plant viruses, viroids and also prions that are proteinaceous infectious agents. Microbes like bacteria and many fungi can be grown on nutritive media to form colonies that can be seen with the naked eyes. Such cultures are useful in studies on micro-organisms. A few of the subtopics are Microbes in Household Products,  Microbes in Industrial Products, Microbes in Sewage Treatment, Microbes in the Production of Biogas, Microbes as Biocontrol Agents and Microbes as Biofertilisers.

Topics Covered in Class 12 CBSE Biology Chapter 10 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.

Also, access the following resources for Class 12 Chapter 10 Microbes in Human Welfare, at BYJU’S.

Chapter 11: Biotechnology Principles and Processes

Biotechnology deals with the technique of using live organisms or enzymes from organisms to produce products and processes useful to humans.  The European Federation of Biotechnology (EFB) has given a definition of biotechnology that encompasses traditional views and modern molecular biotechnology. The definition given by EFB is as follows: ‘The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services.’ Some of the subtopics mentioned in the chapter are Principles of Biotechnology, Tools of Recombinant DNA Technology and Processes of Recombinant DNA Technology.

Topics Covered in Class 12 CBSE Biology Chapter 11 Biotechnology Principles and Processes 

Genetic Engineering (Recombinant DNA Technology).

Also, access the following resources for Class 12 Chapter 11 Biotechnology Principles and Processes, at BYJU’S.

Chapter 12: Biotechnology and Its Application

Biotechnology, as students would have learnt from the previous chapter, deals with the industrial-scale production of biopharmaceuticals and biologicals using genetically modified microbes, fungi, plants and animals. The applications of biotechnology include therapeutics, diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste treatment and energy production. The chapter also includes topics such as Biotechnological Applications in Agriculture, Biotechnological Applications in Medicine, Transgenic Animals and Ethical Issues.

Topics Covered in Class 12 CBSE Biology 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.

Also, access the following resources for Class 12 Chapter 12 Biotechnology and Its Application, at BYJU’S.

Chapter 13: Organisms and Populations

Students have already learnt in the previous classes that Ecology is a subject which studies the interactions among organisms and between the organism and its physical (abiotic) environment. Ecology deals with four levels of biological organisation – organisms, populations, communities and biomes. In this chapter, we explore Ecology at organismic and population levels. It also includes subtopics such as Organism and Its Environment and Populations.

Topics Covered in Class 12 CBSE Biology Chapter 13 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)

Also, access the following resources for Class 12 Chapter 13 Organisms and Populations, at BYJU’S.

Chapter 14: Ecosystem

An ecosystem can be visualised as a functional unit of nature, where living organisms interact among themselves and also with the surrounding physical environment. In this chapter, we will first look at the structure of the ecosystem in order to appreciate the input (productivity), transfer of energy (food chain/web, nutrient cycling) and output (degradation and energy loss). We will also look at the relationships – cycles, chains, webs – that are created as a result of these energy flows within the system and their inter-relationship. Besides, it includes subtopics such as Ecosystem – Structure and Function, Productivity, Decomposition, Energy Flow, Ecological Pyramids, Ecological Succession, Nutrient Cycling and Ecosystem Services.

Topics Covered in Class 12 CBSE Biology Chapter 14 Ecosystem 

Ecosystems: Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy (Topics excluded: Ecological Succession and Nutrient Cycles)

Also, access the following resources for Class 12 Chapter 14 Ecosystem, at BYJU’S.

Chapter 15: Biodiversity and Conservation

Biodiversity and Conservations consist of topics like Genetic diversity, Species diversity, Ecological diversity, Different types of Species, Patterns of Diversity, Loss of Biodiversity, Biodiversity Conservation, etc. Biodiversity conservation may be in situ as well as ex situ. In in situ conservation, the endangered species are protected in their natural habitat so that the entire ecosystem is protected. Ex situ conservation methods include protective maintenance of threatened species in zoological parks and botanical gardens, in vitro fertilisation, tissue culture propagation and cryopreservation of gametes.

Topics Covered in Class 12 CBSE Biology Chapter 15 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.

Also, access the following resources for Class 12 Chapter 15 Biodiversity and Conservation, at BYJU’S.

Chapter 16: Environmental Issues

The human population size has grown enormously over the last hundred years. This means an increase in demand for food, water, home, electricity, roads, automobiles and numerous other commodities. Pollution is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. The agents that bring about such an undesirable change are called pollutants. The other subtopics students will study in this chapter are Air Pollution and Its Control, Water Pollution and Its Control, Solid Wastes, Agrochemicals and Their Effects, Radioactive Wastes, Greenhouse Effect and Global Warming, Ozone Depletion in the Stratosphere, Degradation by Improper Resource Utilisation and Maintenance, and Deforestation.

Several important concepts, such as reproduction, inheritance, evolution, food production, biotechnology, ecosystem, biodiversity, are explained in-depth. The concepts have also been updated as per the latest syllabus prescribed by the CBSE board.

Also, access the following resources for Class 12 Chapter 16 Environmental Issues, at BYJU’S.

At BYJU’S, we craft solutions and other study materials by understanding their importance and implications on academic excellence. Hence, we have designed Class 12 NCERT Solutions, learning resources aimed to help students study and achieve results.

CBSE Marking Scheme 2022-23

Students will be facing the board exams twice in their lifetime. One is Class 10, and the other one is Class 12. The score obtained in Class 10 helps students to understand the subject in which they are strong, and the marks scored in Class 12 help students plan their future. Keeping this in mind, the CBSE board has equally divided the entire syllabus to help students learn all the concepts easily. Going through the course structure updated by the CBSE board, students will be able to understand the chapters which are of more marks and work on them accordingly.

Units Title Marks
VI Reproduction: Chapters – 2, 3 and 4 16
VII Genetics and Evolution: Chapters – 5, 6 and 7 20
VIII Biology and Human Welfare: Chapters – 8,9 and 10 12
IX Biotechnology and its Applications: Chapters – 11 and 12 12
X Ecology and Environment: Chapters – 13, 14 and 15 10
Total 100

Class 12 Biology NCERT Solutions

Biology NCERT Solutions for Class 12 are more effective than any other educational resource. We provide elaborate explanations, detailed solutions, descriptive diagrams and more. Further, we provide accurate and updated answers to all the exercise questions given in NCERT textbooks.

Downloadable files of eBooks, notes, and PDFs are also available to let students study at their convenience.

Read More: NCERT Solutions for Classes 4 to 12

Benefits of Biology NCERT Solutions Class 12

  • Researched and written by experienced teachers
  • New Value-based Questions with solutions in each chapter
  • Jargon-free, easy language
  • Content formulated as per the CBSE curriculum
  • Extensive coverage of fundamental concepts
  • The best resource for CBSE board exam preparation

Detailed Analysis of NCERT Solutions Class 12 Biology

NCERT Textbooks are well known for their simplicity and straightforward description of concepts. These textbooks are ideal for students of CBSE Class 12. It comprises questions that test their conceptual understanding.

The Biology NCERT Solutions Class 12 features all the necessary information with basic concepts to help the students in preparation for medical entrance exams, like NEET.

Important Topics under NCERT Solutions Class 12 Biology

  • Principles of Inheritance and Variations
  • Reproduction in organisms
  • Microbes in Human Welfare
  • Evolution
  • Biotechnology

Class 12 NCERT Biology Solutions Practice Questions

Q1. What is the asexual reproductive structure in Sponge?

Q2. True or false: Independent assortment can be seen in a monohybrid cross.

Q3. Write one difference each between the Oestrus cycle and the Menstrual cycle.

Q4. Elaborate on the following.

  1. Apomixis
  2. Scutellum

Q5. How are microspores in angiosperms developed?

Q6. Name the hormones produced by women during pregnancy.

Q7. Write one difference between codominance and incomplete dominance.

Q8. Who rediscovered Mendel’s laws?

Q9. YyRr is crossed with a wrinkled pea plant. Explain the result with the diagram.

Q10. Define mutagen. Give one example.

Q11. Define MTP.

Q12. What is menarche?

Q13. Draw a labelled diagram of the seminiferous tubule.

Q14. Which part of the fallopian tube is closest to the ovary?

Q15. Draw an anatropous ovule and label any six parts.

Q16. What happens to Synergids after fertilisation?

Q17. What is the significant difference between autogamy, xenogamy, and geitonogamy?

Q18. What are the gamete mother cells called in diploid organisms?

Q19. Explain the process of cross-pollination in plants.

Discover more questions, concepts and topics in CBSE Biology at BYJU’S. Also, explore NCERT solutions for Maths, Physics, and Chemistry by registering at BYJU’S.

Frequently Asked Questions on NCERT Solutions for Class 12 Biology

How do NCERT Solutions of Class 12 Biology help in exam preparation?

The questions provided in NCERT textbooks can offer an excellent boost to study thoroughly and score excellently during examinations and tests. Students can effectively start practising NCERT Solutions Class 12 Biology, which will happen in more immeasurable performance in further studies. This, in turn, would build a strong grip on the syllabus.

Which book is best for Class 12 Biology?

The most esteemed book for the Class 12 exam is NCERT Biology Textbook. This book strictly follows the CBSE curriculum. It helps to form the base for preparing for the board examinations, as it contains question papers that are set according to the prescribed CBSE syllabus of the subject.

How to download NCERT Solutions for Class 12 Biology?

Visit BYJU’S website and select NCERT Solutions, or go to the link https://byjus.com/ncert-solutions/, select Class 12/select subject and view/download the solutions. These solutions provided by BYJU’S cover all concepts with detailed explanations.

Does BYJU’S website provide free NCERT Biology Solutions for Class 12?

Yes, these solutions can be viewed and downloaded in free PDF format. Students who find it difficult to solve exercise-wise questions in the NCERT textbook can access PDF solutions. The questions are solved by our experts in the best possible way to make it easier for the students during exam preparation.

What is the structure responsible for asexual reproduction in sponges?

Gemmules are the structure responsible for asexual reproduction in sponges.

Explain the law of independent assortment.

The law of independent assortment states that the alleles of two or more different genes get sorted into gametes independent of one another.

What is apomixis?

Apoximis is a form of asexual reproduction that occurs without fertiliSation and does not involve meiosis. This form of reproduction is more common in plants.

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