NCERT Solutions for Class 12 Biology

NCERT Solutions for Class 12 Biology – FREE PDF Download

For all the medical aspirants, Biology is the most important subject that you need to focus on in your Class 12 final examination. Class 12 Biology examination is extensive and requires a lot of understanding and knowledge of the basics of the subject. You will need to start studying beforehand because the syllabus is vast and extensive. So you will need to invest a lot of time in order to finish the entire syllabus. Also, keep in mind that you need to have time for practice and revision of the chapters as well. In this blog, we are going to discuss some important tips regarding Class 12 Biology NCERT. NCERT Solutions for Class 12 Biology provided in this page contains solutions that are prescribed for textbooks you use in the CBSE syllabus

Biology Revision Notes for Class 12


NCERT Solutions for Class 12 Biology – Free PDF Download

As per the latest CBSE syllabus, Class 12 Biology book has 16 chapters that are –

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, the reproduction is asexual. When two parents (opposite sex) participate in the reproductive process and also involve the fusion of male and female gametes, it is called sexual reproduction. These concepts are elaborately explained with relevant diagrams and suitable examples, etc.

Chapter 2: Sexual Reproduction in Flowering Plants

Sexual Reproduction in Flowering Plants explains the morphology, structure and the 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.

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 reaching 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, you 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, menstrual cycle, fertilisation and implantation, pregnancy and embryonic development, parturition and lactation.

Chapter 4: Reproductive Health

In the previous chapter, you have learnt about human reproductive system and its functions. This chapter discusses a closely related topic – reproductive health. The term simply refers to healthy reproductive organs with normal functions. According to the World Health Organisation (WHO), reproductive health means total well-being in all 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, Infertility.

Chapter 5: Principles of Inheritance and Variation

Genetics is a branch of Biology that deals with the inheritance, as well as the variation of characters from parents to offspring. Inheritance is the process by which 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, Genetic Disorders

Chapter 6: Molecular Basis of Inheritance

In the previous chapter, you 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 you have learnt that nucleic acids are polymers of nucleotides. It also includes subtopics such as The DNA, The Search for Genetic
Material, RNA World, Replication, Transcription, Genetic Code, Translation, Regulation of Gene Expression, Human Genome Project, DNA Fingerprinting.

Chapter 7: Evolution

Evolutionary Biology is the study of 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.

Chapter 8: Human Health and Diseases

Health, for a long time, was considered as a state of body and mind where there was a balance of certain humor. 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.

Chapter 9: Strategies for Enhancement in Food Production

With ever-increasing population of the world, 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 the chapter are Animal Husbandry, Plant Breeding, Single Cell Proteins, Tissue Culture.

Chapter 10: Microbes in Human Welfare

Besides macroscopic plants and animals, microbes are the major components of biological systems on this earth. You have studied about 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. Few of the subtopics are Microbes in Household Products,  Microbes in Industrial Products, Microbes in Sewage Treatment, Microbes in Production of Biogas, Microbes as Biocontrol Agents, Microbes as Biofertilisers.

Chapter 11: Biotechnology Principles and Processes

Biotechnology deals with techniques 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 both traditional view 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, Processes of Recombinant DNA Technology.

Chapter 12: Biotechnology: and its Application

Biotechnology, as you would have learnt from the previous chapter, essentially deals with 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, Ethical Issues.

Chapter 13: Organisms and Populations

You have already learnt in previous classes that Ecology is a subject which studies the interactions among organisms and between the organism and its physical (abiotic) environment. Ecology is basically concerned 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, Populations.

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 the 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. It includes subtopics Ecosystem–Structure and Function, Productivity, Decomposition, Energy Flow, Ecological Pyramids, Ecological Succession, Nutrient Cycling, Ecosystem Services.

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.

Chapter 16: Environmental Issues

Human population size has grown enormously over the last hundred years. This means 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. Agents that bring about such an undesirable change are called as pollutants. 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, 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 CBSE.

CoolGyan is a learning company, and we thoroughly understand the importance of study materials and their implications on academic excellence. Hence, we designed Class 12 NCERT solutions, a learning resource aimed to help students study and achieve results.

Class 12 Biology NCERT Solutions

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

Downloadable files of ebooks, notes, 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 CBSE curriculum
  • Extensive coverage of fundamental concepts
  • Solved Exemplar problems
  • 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.

Biology NCERT Solutions class 12 feature all the necessary information with basic concepts to help the students in the preparation of 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

Frequently Asked Questions

1. What is the structure responsible for asexual reproduction in sponges?

Gemmules are the structure responsible for asexual reproduction in sponges.

2. 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.

3. What is apomixis?

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

4. What is scutellum? (with respect to plants)

The scutellum is a modified, shield-shaped cotyledon of a monocot (like the seeds of grass)

5. Name the test used for the detection of AIDS?

ELISA (Enzyme-linked immunosorbent assay) is the preliminary test. Western Blotting is a confirmatory test used to detect AIDS

6. What is metastasis?

Metastasis is the phenomenon where tumour cells spread to different parts of the body through the circulatory system

7. What is contact inhibition?

Contact inhibition is a process by which normal cells inhibit their growth process in contact with neighbouring cells.

8. What is immunity? Mention the types of immunity.

Immunity can be defined as the ability of the host to fight against a disease-causing microbe or an agent. Immunity can be of two types – Innate immunity and acquired immunity.

9. What is phylogenetics?

Phylogenetics is the study of evolutionary history and relationship among individuals or group of organisms. Protein or gene evolution plays a major important role here.

10. What is the motile infective form of the Plasmodium parasite called?


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 Oestrus cycle and Menstrual cycle

Q4. Elaborate 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 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 anatropous ovule and label any six parts.

Q16. What happens to Synergids after fertilization?

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 Biology on CoolGyan. Alternatively, explore NCERT solutions for Maths, Physics, and Chemistry at CoolGyan.