Complete Class 12 Biology NCERT Book & Solutions PDF (2025-26)

The syllabus consists of five units: (vi) Reproduction (vii) Genetics and Evolution (viii) Biology and Human Welfare (ix) Biotechnology and its Applications (x) Ecology and Environment. Theory paper is of 3 hours and 70 marks.

Exam Structure

Topics in Class 12 Biology

Unit VI: Reproduction

• Chapter 1: Reproduction in Organisms

Subtopics- Reproduction, a characteristic feature of all organisms for continuation of species; modes of reproduction - asexual and sexual reproduction; asexual reproduction - binary fission, sporulation, budding, gemmule formation, fragmentation; vegetative propagation in plants; events in sexual reproduction.

• Chapter 2: Sexual Reproduction in Flowering Plants

Subtopics- Flower structure; Development of male and female gametophytes; Pollination-types, agencies and examples; outbreeding devices; Pollen-Pistil interaction; Double fertilization; Post fertilization events-Development of endosperm and embryo, Development of seed and formation of fruit; Special modes-apomixis, parthenocarpy, polyembryony; Significance of seed and fruit formation.

• Chapter 3: Human Reproduction

Subtopics- Male and female reproductive systems; Microscopic anatomy of testis and ovary; Gametogenesis-spermatogenesis & oogenesis; Menstrual cycle; Fertilization embryo development upto blastocyst formation, implantation; Pregnancy and placenta formation (Elementary idea); Parturition (elementary idea); Lactation (elementary idea).

• Chapter 4: Reproductive Health

Subtopics- Need for reproductive health and prevention of sexually transmitted diseases (STD); Birth control - Need and Methods, Contraception and Medical Termination of Pregnancy (MTP); Amniocentesis; Infertility and assisted reproductive technologies - IVF, ZIFT, GIFT, AI (brief overview).  

Unit VII: Genetics and Evolution

• Chapter 5: Principles of Inheritance and Variation

Subtopics- 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; linkage and crossing over; Sex determination - in human being, birds, grasshopper and honey bee; Mutation, Pedigree analysis, sex-linked inheritance - haemophilia, colour blindness; Mendelian disorders in humans - sickle cell anaemia, Phenylketonuria, thalassemia; chromosomal disorders in humans; Down's syndrome, Turner's and Klinefelter's syndromes.

• Chapter 6: Molecular Basis of Inheritance

Subtopics- Structure of DNA and RNA; DNA packaging; Search for genetic material and DNA as genetic material; DNA replication; Central Dogma; transcription, genetic code, translation; gene expression and regulation - lac operon; Human genome project; DNA fingerprinting.

• Chapter 7: Evolution

Subtopics- Origin of life; biological evolution and evidences for biological evolution (paleontology, comparative anatomy, embryology and molecular evidences); adaptive radiation; Biological evolution: Lamarck’s theory of use and disuse of organs, Darwin's 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; brief account of evolution; human evolution.

Unit VIII: Biology and Human Welfare

• Chapter 8: Human Health and Diseases

Subtopics- Pathogens; parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm) and their control; Basic concepts of immunology - vaccines; cancer, HIV and AIDS; Adolescence - drug and alcohol abuse.

• Chapter 9: Strategies for Enhancement in Food Production

Subtopics- Animal husbandry, Plant breeding, tissue culture, single cell protein.

• Chapter 10: Microbes in Human Welfare

Subtopics-Microbes in food processing, industrial production, Antibiotics; production and judicious use, sewage treatment, energy generation and microbes as biocontrol agents and bio-fertilizers.

Unit IX: Biotechnology and Its Applications

• Chapter 11: Biotechnology - Principles and Processes

Subtopics- Genetic engineering (Recombinant DNA technology). 

• Chapter 12: Biotechnology and its Application

Subtopics- Application of biotechnology in health and agriculture: genetically modified organisms - Bt crops; RNA interference, Human insulin, gene therapy; molecular diagnosis; transgenic animals; biosafety issues, biopiracy and patents.

Unit X: Ecology and Environment

• Chapter 13: Organisms and Populations

Subtopics- Organisms and environment: Habitat and niche, Population and ecological adaptations; Population interactions - mutualism, competition, predation, parasitism; Population attributes growth, birth rate and death rate, age distribution.

• Chapter 14: Ecosystem

Subtopics- Ecosystem: structure and function; productivity and decomposition; energy flow; pyramids of number, biomass, energy; nutrient cycles (carbon and phosphorous); ecological succession; ecological services - carbon fixation, pollination, seed dispersal, oxygen release (in brief).

• Chapter 15: Biodiversity and its Conservation

Subtopics- Concept of biodiversity; patterns of biodiversity; importance of biodiversity; loss of biodiversity; biodiversity conservation; hotspots, endangered organisms, extinction, Red Data Book, biosphere reserves, national parks, sanctuaries and Ramsar sites.

• Chapter 16: Environmental Issues

Subtopics- Air pollution and its control; water pollution and its control; agrochemicals and their effects; solid waste management; radioactive waste management; greenhouse effect and climate change impact and mitigation; ozone layer depletion; deforestation; case study exemplifying success story addressing environmental issue(s). 

The Best Tips and Methods To Study For Biology For Class 12 Exam  

1. Understand the paper's detailed pattern and syllabus. 

The CBSE publishes specific topic syllabuses and patterns on a regular basis. All the questions in the exam come from a predetermined syllabus. Aside from the syllabus, the paper's pattern is crucial because it can aid in the development of exam-taking skills. 

2. Examine Various Question Variations 

It is critical to become familiar with the several types of Biology questions in order to gain confidence and be able to tackle any question in the exam. Students should practice by solving a variety of sample papers and CBSE Question Papers for Class 12 Biology. Solving these papers not only allows you to become familiar with a wide range of question variations but also allows you to gain a better understanding of the question structure and complexity. 

3. Important Terms and Diagrams to Remember 

There are a lot of key terminology and definitions in Biology that are important for exams. Aside from complex terminology, the subject contains a plethora of significant graphics. To be able to deliver the answer correctly in the exam, thoroughly practice the diagrams and recall the terms. To recall and revise them quickly, use flashcards or a notebook. 

4. Revision in the Right Way 

Because Biology is a theory-heavy topic, students must continue to revise in order to remember the concepts for a longer period. Re-read all the topics and double-check the chapter weightings. 

5. NCERT Books for Class 12 Biology Free PDF Download

Use this as your study material and reference. As most of the exam papers will be made from NCERT Books Class 12 Biology PDF itself. 

Apart from these exam-taking tactics, other exam-taking ideas are also provided below that will help you score higher on the CBSE class 12 Biology exam. 

• Always write clearly and on a new page when starting a new section. 

• Maintain the sequence of the questions. 

• Even if the questions does not specify so, always include a corresponding diagram (labeled) for the 5- and 3-mark questions. 

• Make a note of the essential phrases in the solution. 

• Always set aside 10 to 15 minutes for revising and double-checking for any missing questions. 

These pointers can assist students in better preparing for biology and achieving satisfactory results on their Class 12 exams. 

Conclusion  

One of the most prevalent suggestions for how to study in class 12 is to learn how to study smartly rather than cramming things. After completing tenth grade, most students become perplexed when they are assigned to a stream and introduced to new subjects. Many students utilize ways to memorize information, but regardless of your major, you should not memorize subjects. The key to learning is to comprehend rather than memorize each subject. A well-understood topic will stick in your long-term memory. It will be easier for you to grasp a subject if you clear up your basic comprehension of it. Wherever you're stuck, get assistance from your teachers. Additionally, you have Vedantu, where you can have access to all your educational needs at the price of absolutely nothing. 

Biology introduces a wide range of important topics in Class 12 that are necessary for understanding higher-level ideas in Class 12. In the NEET test, questions about Class 12 Biology themes carry a lot of weight. 

As a result, CBSE Class 12 biology is critical for both the Class 12 and NEET exams. Some significant recommendations and methods are listed below to assist students in better preparing for the Class 12 biology exam.