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Biology Complete Guide

Syllabus, official resources, chapter guides, textbook solutions, question bank, model papers, revision plan, exam tips, and FAQs.

Chapters

22

Published Guides

59

Chapter Guides

26/22

Practice Resources

10

📝 Textbook Exercise Solutions — Chapter-wise

MCQ, short answers, long answers, and numericals with full worked solutions

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Subject Roadmap

Mapped

22 Biology chapters arranged by unit for Class 12.

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Syllabus and Official Resources

Official-first

1 syllabus focus area with Tamil Nadu textbook resources as the primary source.

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Chapter Summaries

Live

26 published chapter guides available for Biology.

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Textbook Exercise Solutions

Live

Exercise workflow pages are live for answer-writing and correction practice.

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Important Questions

Ready

5 question patterns are listed for one-mark, short-answer, and long-answer practice.

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Model Papers

Live

2 model paper resource pages are published.

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Revision Plan

Live

A Class 12 Biology revision plan is available for weekly study cycles.

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Exam Tips

Subject-specific

Exam guidance focuses on biology presentation, keywords, time use, and common mistakes.

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FAQs

In guides

FAQs are included inside individual guides so answers stay close to the exact chapter or resource.

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Syllabus Roadmap

  • Combined Bio Botany and Bio Zoology coverage for reproduction, genetics, biotechnology, ecology, plant breeding, human reproduction, health, microbes, evolution, biodiversity, and environmental issues.

Official Books

Use official Tamil Nadu textbook resources first, then study with KalviGavani chapter guides.

Open TN Textbook Source

Chapter Dashboard

26/22 chapter guides published

Bio Botany · Chapter 1

Bio Botany - Asexual and Sexual Reproduction in Plants

Live
Open guide

Bio Botany · Chapter 2

Bio Botany - Classical Genetics

Live
Open guide

Bio Botany · Chapter 3

Bio Botany - Chromosomal Basis of Inheritance

Live
Open guide

Bio Botany · Chapter 4

Bio Botany - Principles and Processes of Biotechnology

Live
Open guide

Bio Botany · Chapter 5

Bio Botany - Plant Tissue Culture

Live
Open guide

Bio Botany · Chapter 6

Bio Botany - Principles of Ecology

Live
Open guide

Bio Botany · Chapter 7

Bio Botany - Ecosystem

Live
Open guide

Bio Botany · Chapter 8

Bio Botany - Environmental Issues

Live
Open guide

Bio Botany · Chapter 9

Bio Botany - Plant Breeding

Live
Open guide

Bio Botany · Chapter 10

Bio Botany - Economically Useful Plants and Entrepreneurial Botany

Live
Open guide

Bio Zoology · Chapter 11

Bio Zoology - Reproduction in Organisms

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Open guide

Bio Zoology · Chapter 12

Bio Zoology - Human Reproduction

Live
Open guide

Bio Zoology · Chapter 13

Bio Zoology - Reproductive Health

Live
Open guide

Bio Zoology · Chapter 14

Bio Zoology - Principles of Inheritance and Variation

Live
Open guide

Bio Zoology · Chapter 15

Bio Zoology - Molecular Genetics

Live
Open guide

Bio Zoology · Chapter 16

Bio Zoology - Evolution

Live
Open guide

Bio Zoology · Chapter 17

Bio Zoology - Human Health and Diseases

Live
Open guide

Bio Zoology · Chapter 18

Bio Zoology - Microbes in Human Welfare

Live
Open guide

Bio Zoology · Chapter 19

Bio Zoology - Applications of Biotechnology

Live
Open guide

Bio Zoology · Chapter 20

Bio Zoology - Organisms and Populations

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Bio Zoology · Chapter 21

Bio Zoology - Biodiversity and Its Conservation

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Bio Zoology · Chapter 22

Bio Zoology - Environmental Issues

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Question Bank

  • Definitions and biological terms
  • Labelled diagrams
  • Genetics and biotechnology reasoning
  • Process explanations
  • Public exam application questions

Model Papers

  • After each unit, solve a short unit test.
  • After every major section, revise mistakes before moving to the next unit.
  • In the final month, write one full subject model paper every week.
  • Use the last revision cycle only for weak topics, formulae, diagrams, grammar rules, maps, or key terms.

Revision Plan

  • Week 1: Read the official textbook and mark glossary, formulae, dates, rules, and diagrams.
  • Week 2: Complete textbook exercises and correct repeated mistakes.
  • Week 3: Practise important questions, unit tests, diagrams, maps, grammar, and writing formats.
  • Week 4: Write model papers and revise only the mistake notebook.

Published Chapter Guides

Guide

Tamil Nadu Class 12 Biology — Genetics and Heredity Notes & Important Questions

Complete Samacheer Kalvi Class 12 Biology Genetics guide — Mendel's laws, monohybrid and dihybrid crosses, codominance, linkage, mutations, and board exam Q&A.

22 May 2026

Guide

Tamil Nadu Class 12 Biology — Molecular Biology and DNA Notes

Samacheer Kalvi Class 12 Biology DNA structure, Watson-Crick model, DNA replication, transcription, translation, genetic code, lac operon — board exam and NEET guide.

22 May 2026

Guide

Tamil Nadu Class 12 Biology — Plant Physiology Notes & Important Questions

Complete Samacheer Kalvi Class 12 Biology Plant Physiology guide — photosynthesis light and dark reactions, C3 C4 CAM plants, plant respiration, transpiration, phytohormones, board exam Q&A.

22 May 2026

Guide

Tamil Nadu Class 12 Biology — Human Reproduction Notes & Important Questions

Complete Samacheer Kalvi Class 12 Biology Human Reproduction guide — male and female reproductive systems, menstrual cycle, gametogenesis, fertilisation, embryonic development, board exam Q&A.

22 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Evolution Notes — Samacheer Kalvi

Complete Bio Zoology notes on Evolution for Tamil Nadu Class 12 Biology with evidence, Darwinism, natural selection, Hardy-Weinberg principle, and exam questions.

17 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Molecular Genetics Notes — Samacheer Kalvi

Complete Bio Zoology notes on Molecular Genetics for Tamil Nadu Class 12 Biology with DNA structure, replication, transcription, translation, genetic code, and exam questions.

17 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Inheritance and Variation Notes — Samacheer Kalvi

Complete Bio Zoology notes on Principles of Inheritance and Variation for Tamil Nadu Class 12 Biology with Mendel laws, crosses, sex determination, pedigree basics, and exam questions.

17 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Human Reproduction Notes — Samacheer Kalvi

Complete Bio Zoology notes on Human Reproduction for Tamil Nadu Class 12 Biology with male and female systems, gametogenesis, menstrual cycle, fertilisation, and exam questions.

16 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Reproduction in Organisms Notes — Samacheer Kalvi

Complete Bio Zoology notes on Reproduction in Organisms for Tamil Nadu Class 12 Biology with asexual and sexual reproduction, life cycles, comparisons, and exam questions.

16 May 2026

chapter-guide

Tamil Nadu Class 12 Biology Reproductive Health Notes — Samacheer Kalvi

Complete Bio Zoology notes on Reproductive Health for Tamil Nadu Class 12 Biology with contraception, STIs, infertility, ART, awareness, and exam questions.

16 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Asexual and Sexual Reproduction in Plants

Samacheer Kalvi Class 12 Biology Bio Botany - Asexual and Sexual Reproduction in Plants guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Chromosomal Basis of Inheritance

Samacheer Kalvi Class 12 Biology Bio Botany - Chromosomal Basis of Inheritance guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Classical Genetics

Samacheer Kalvi Class 12 Biology Bio Botany - Classical Genetics guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Economically Useful Plants and Entrepreneurial Botany

Samacheer Kalvi Class 12 Biology Bio Botany - Economically Useful Plants and Entrepreneurial Botany guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Ecosystem

Samacheer Kalvi Class 12 Biology Bio Botany - Ecosystem guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Environmental Issues

Samacheer Kalvi Class 12 Biology Bio Botany - Environmental Issues guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Plant Breeding

Samacheer Kalvi Class 12 Biology Bio Botany - Plant Breeding guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Plant Tissue Culture

Samacheer Kalvi Class 12 Biology Bio Botany - Plant Tissue Culture guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Principles and Processes of Biotechnology

Samacheer Kalvi Class 12 Biology Bio Botany - Principles and Processes of Biotechnology guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Botany - Principles of Ecology

Samacheer Kalvi Class 12 Biology Bio Botany - Principles of Ecology guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Applications of Biotechnology

Samacheer Kalvi Class 12 Biology Bio Zoology - Applications of Biotechnology guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Biodiversity and Its Conservation

Samacheer Kalvi Class 12 Biology Bio Zoology - Biodiversity and Its Conservation guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Environmental Issues

Samacheer Kalvi Class 12 Biology Bio Zoology - Environmental Issues guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Human Health and Diseases

Samacheer Kalvi Class 12 Biology Bio Zoology - Human Health and Diseases guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Microbes in Human Welfare

Samacheer Kalvi Class 12 Biology Bio Zoology - Microbes in Human Welfare guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

chapter-guide

Tamil Nadu Class 12 Biology: Bio Zoology - Organisms and Populations

Samacheer Kalvi Class 12 Biology Bio Zoology - Organisms and Populations guide with summary, textbook workflow, important questions, practice tasks, common mistakes, and revision checklist.

10 May 2026

Exercise Solutions

Chapter-wise textbook answers with a quick path back to notes.

View all solutions →
Ch 1

Asexual and Sexual Reproduction in Plants Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 1 Asexual and Sexual Reproduction in Plants exercise solutions with key diagrams, definitions, short answers, and exam tips.

25 May 2026

Ch 2

Classical Genetics Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 2 Classical Genetics exercise solutions — Mendel's laws, dihybrid cross, codominance, linkage, and exam problem-solving steps.

25 May 2026

Ch 3

Chromosomal Basis of Inheritance Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 3 Chromosomal Basis of Inheritance exercise solutions — sex determination, sex-linked inheritance, chromosomal disorders, and exam tips.

25 May 2026

Ch 4

Molecular Genetics Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 4 Molecular Genetics exercise solutions — DNA structure, replication, transcription, translation, gene regulation, and exam tips.

25 May 2026

Ch 5

Environmental Issues Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 5 Environmental Issues (Botany) exercise solutions — pollution, deforestation, conservation, biodiversity, and exam tips.

25 May 2026

Ch 6

Principles of Ecology Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 6 Principles of Ecology exercise solutions — ecosystem components, energy flow, ecological pyramids, biogeochemical cycles, and exam tips.

25 May 2026

Ch 7

Plant Tissue Culture Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 7 Plant Tissue Culture exercise solutions — totipotency, explant, callus, somatic embryogenesis, micropropagation, and exam tips.

25 May 2026

Ch 8

Principles and Processes of Biotechnology Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 8 Principles and Processes of Biotechnology exercise solutions — recombinant DNA, restriction enzymes, PCR, gel electrophoresis, and exam tips.

25 May 2026

Ch 9

Plant Breeding and Crop Improvement Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 9 Plant Breeding and Crop Improvement exercise solutions — hybridisation, mutation breeding, green revolution, biofortification, and exam tips.

25 May 2026

Ch 10

Economically Useful Plants Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 10 Economically Useful Plants exercise solutions — food crops, fibres, timber, medicinal plants, and exam tips.

25 May 2026

Ch 11

Reproduction in Organisms Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 11 Reproduction in Organisms exercise solutions — types of reproduction, asexual modes, sexual reproduction events, and exam tips.

25 May 2026

Ch 12

Human Reproduction Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 12 Human Reproduction exercise solutions — male and female reproductive systems, gametogenesis, menstrual cycle, fertilisation, and exam tips.

25 May 2026

Ch 13

Reproductive Health Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 13 Reproductive Health exercise solutions — contraception, STDs, infertility, ART (IVF, GIFT, ICSI), and exam tips.

25 May 2026

Ch 14

Principles of Inheritance and Variation Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 14 Principles of Inheritance and Variation exercise solutions — Mendel's laws, blood groups, genetic disorders, and exam tips.

25 May 2026

Ch 15

Molecular Genetics Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 15 Molecular Genetics (Zoology) exercise solutions — Human Genome Project, DNA fingerprinting, gene therapy, and exam tips.

25 May 2026

Ch 16

Evolution Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 16 Evolution exercise solutions — theories of evolution, natural selection, Hardy-Weinberg law, evidences, and exam tips.

25 May 2026

Ch 17

Human Health and Diseases Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 17 Human Health and Diseases exercise solutions — immunity types, pathogens, cancer, drugs of abuse, and exam tips.

25 May 2026

Ch 18

Microbes in Human Welfare Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 18 Microbes in Human Welfare exercise solutions — industrial microbes, biogas, bioremediation, antibiotics, and exam tips.

25 May 2026

Ch 19

Biotechnology and its Applications Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 19 Biotechnology and its Applications exercise solutions — transgenic organisms, Bt crops, insulin production, gene therapy, bioethics, and exam tips.

25 May 2026

Ch 20

Organisms and Populations Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 20 Organisms and Populations exercise solutions — population attributes, growth models, ecological interactions, and exam tips.

25 May 2026

Ch 21

Biodiversity and Conservation Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 21 Biodiversity and Conservation exercise solutions — types of biodiversity, threats, in situ and ex situ conservation, hotspots, and exam tips.

25 May 2026

Ch 22

Environmental Issues Exercise Solutions

Tamil Nadu Class 12 Biology Chapter 22 Environmental Issues (Zoology) exercise solutions — pollution effects on animals, biomagnification, solid waste, radioactive pollution, and exam tips.

25 May 2026

Practice Resources

unit-test

Tamil Nadu Class 12 Biology Term 2 Unit Test — Samacheer Kalvi

Class 12 Biology Term 2 practice test for Tamil Nadu State Board students with questions from inheritance, molecular genetics, evolution, health, and biotechnology.

17 May 2026

unit-test

Tamil Nadu Class 12 Biology Term 1 Unit Test — Samacheer Kalvi

Class 12 Biology Term 1 practice test for Tamil Nadu State Board students with questions from reproduction, inheritance, and molecular genetics.

16 May 2026

revision-plan

Tamil Nadu Class 12 Biology 30-Day Revision Plan — Samacheer Kalvi

Class 12 Biology 30-day revision plan for Tamil Nadu State Board students with weekly revision cycles, term-wise planning, model-paper practice, and mistake correction.

10 May 2026

drill-practice

Tamil Nadu Class 12 Biology Biology Diagram Bank — Samacheer Kalvi

Class 12 Biology biology diagram bank for Tamil Nadu State Board students with labelled diagrams, parts, functions, and neat presentation practice.

10 May 2026

question-bank

Tamil Nadu Class 12 Biology Biology Key Terms Bank — Samacheer Kalvi

Class 12 Biology biology key terms bank for Tamil Nadu State Board students with botany and zoology definitions, differences, and process keywords.

10 May 2026

model-paper

Tamil Nadu Class 12 Biology Model Paper 1 — Samacheer Kalvi

Class 12 Biology model paper 1 for Tamil Nadu State Board students with term-wise sections, written answer practice, and time management.

10 May 2026

model-paper

Tamil Nadu Class 12 Biology Model Paper 2 — Samacheer Kalvi

Class 12 Biology model paper 2 for Tamil Nadu State Board students with term-wise sections, written answer practice, and time management.

10 May 2026

question-bank

Tamil Nadu Class 12 Biology Question Bank — Samacheer Kalvi

Class 12 Biology question bank for Tamil Nadu State Board students with chapter-wise one-mark, short-answer, long-answer, and term revision practice.

10 May 2026

unit-test

Tamil Nadu Class 12 Biology Term 3 Unit Test — Samacheer Kalvi

Class 12 Biology term 3 unit test for Tamil Nadu State Board students with term-wise chapter checks, short tests, and correction checklist.

10 May 2026

textbook-solutions

Tamil Nadu Class 12 Biology Biology Textbook Solutions Map — Samacheer Kalvi

Class 12 Biology biology textbook solutions map for Tamil Nadu State Board students with chapter-wise exercise workflow for Bio Botany and Bio Zoology.

10 May 2026