11th NCERT Biology PDF: What’s Inside the Class 11 Book

The 11th NCERT Biology PDF on this page covers the whole Class 11 NCERT Biology textbook — 19 chapters across 252 printed pages — and every chapter’s official file is linked below.

What the PDF alone does not show is where the content and question load actually sit. Below the download table, every chapter is measured by its named sections, indexed figures and exercise questions, so you can plan revision before opening a single file.

Download the Class 11 Biology NCERT book PDFs

Every file in the table below is NCERT’s own official PDF, hosted on ncert.nic.in and free to download and print. Each row gives the chapter number, title, printed page range and the direct link to the official file.

Reference: NCERT Class 11 Biology textbook, official edition on ncert.nic.in. Figure captions and section titles quoted from the textbook; page references are to the official PDF.

The book, measured: what this Class 11 Biology NCERT PDF contains

Headline numbers for the whole volume, read from the official PDFs:

• 19 chapters, each with a verified official PDF linked above
• 252 printed pages across the full book
• 251 named sections, NCERT’s own numbered headings
• 142 verified numbered figures indexed from the textbook
• 211 exercise questions, all sitting at the ends of chapters
• 0 activity boxes in the entire book
• 19 chapter study pages, each listed with its current status below

The chapter list groups naturally into five reading blocks. This is this page’s grouping of the chapter list, not an official NCERT division:

Each chapter, measured: sections, figures and exercises

The directory below counts each chapter by three measures: a section is one of NCERT’s own numbered headings, a figure is a numbered figure indexed from the textbook, and a question is an end-of-chapter exercise.

Every chapter in this book prints a SUMMARY, so the explanations below compress that recap into plain language and list the chapter’s own topics with the printed page each begins on.

Chapter 1: The Living World (pp. 1-9)

The living world holds far more variety than science has so far recorded: millions of species are identified and described, while a large number still remain unknown. What makes that diversity studyable is classification, taxonomy and nomenclature — grouping organisms, naming them, and doing both by a standard system.

1. Diversity in the Living World (p. 3)
2. Taxonomic Categories (p. 6)

The hierarchy runs upward from Species (p. 6) through Genus, Family, Order, Class and Phylum to Kingdom (p. 8). With 11 named sections, 1 indexed figure and 14 exercise questions across 9 pages, this chapter loads the classification vocabulary every later chapter uses.

Chapter 2: Biological Classification (pp. 10-22)

Aristotle attempted the earliest biological classification using simple morphological characters; Linnaeus later supplied the hierarchy that made it systematic. The chapter then maps the five-kingdom system — Monera, Protista, Fungi, Plantae and Animalia — and closes with the virus-like groups that fit none of them.

1. Kingdom Monera (p. 12)
2. Kingdom Protista (p. 14)
3. Kingdom Fungi (p. 16)
4. Kingdom Plantae (p. 19)
5. Kingdom Animalia (p. 19)
6. Viruses, Viroids, Prions and Lichens (p. 19)

With 5 indexed figures, 12 questions and 13 pages, this is the framework chapter that Plant Kingdom and Animal Kingdom both assume.

Chapter 3: Plant Kingdom (pp. 23-36)

The plant kingdom is arranged in five groups — algae, bryophytes, pteridophytes, gymnosperms and angiosperms. Algae are chlorophyll-bearing, thalloid, autotrophic and largely aquatic; the four later groups are each treated in turn.

1. Algae (p. 24) — Chlorophyceae (p. 26), Phaeophyceae (p. 26), Rhodophyceae (p. 27)
2. Bryophytes (p. 28) — Liverworts (p. 29), Mosses (p. 30)
3. Pteridophytes (p. 30)
4. Gymnosperms (p. 32)
5. Angiosperms (p. 34)

Across 14 pages with 5 figures and 10 questions, the figures — from Volvox and Ulothrix through to the dicot and monocot — do much of the teaching.

Chapter 4: Animal Kingdom (pp. 37-54)

Animal classification rests on a few fundamental features: level of organisation, symmetry, cell organisation, coelom, segmentation and the notochord. On that basis the chapter sorts the animals into eleven phyla, from Porifera to Chordata.

1. Basis of Classification (p. 37) — Levels of Organisation, Symmetry, Diploblastic and Triploblastic Organisation, Coelom, Segmentation, Notochord (pp. 37-39)
2. Classification of Animals (p. 39) — the eleven phyla from Porifera to Chordata (pp. 40-45)

The book’s most visual chapter — 24 indexed figures, 15 questions and 18 pages — its phylum examples, from Sycon to Balaenoptera, are the content.

Chapter 5: Morphology of Flowering Plants (pp. 55-70)

Flowering plants vary enormously in shape, size, structure and habitat, yet every one carries a well developed root system and shoot system. The chapter reads the plant part by part — root, stem, leaf, inflorescence, flower, fruit and seed — and ends with a formal description of a typical flowering plant.

1. The Root (p. 57)
2. The Stem (p. 59)
3. The Leaf (p. 59)
4. The Inflorescence (p. 61)
5. The Flower (p. 62)
6. The Fruit (p. 65)
7. The Seed (p. 66)
8. Semi-Technical Description of a Typical Flowering Plant (p. 67)
9. Solanaceae (p. 68)

With 17 figures and 10 questions across 16 pages, Solanum nigrum (Fig. 5.17, p. 68) is the worked example that ties flower parts, floral formula and floral diagram together.

Chapter 6: Anatomy of Flowering Plants (pp. 71-78)

Anatomically, a plant is a collection of tissues, broadly grouped as meristematic (apical, lateral and intercalary) and permanent. The chapter maps the three tissue systems — epidermal, ground and vascular — then reads transverse sections of dicot and monocot roots, stems and leaves.

1. The Tissue System (p. 71) — Epidermal, Ground and Vascular Tissue Systems (pp. 71-73)
2. Anatomy of Dicotyledonous and Monocotyledonous Plants (p. 73) — dicot and monocot root, stem and leaf (pp. 73-77)

At 8 pages with 13 named sections, 5 T.S. diagrams and 7 questions, revision is about reading labelled cross sections rather than memorising prose.

Chapter 7: Structural Organisation in Animals (pp. 79-84)

Cells, tissues, organs and organ systems split up the work of the body so it survives as a whole — division of labour. The chapter works out that principle through a single animal, the frog, from external morphology to internal anatomy.

1. Organ and Organ System (p. 79)
2. Frogs (p. 80) — Morphology (p. 80), Anatomy (p. 81)

The shortest chapter in the book — 6 pages, 4 frog figures and only 2 exercise questions — it is a quick read before the physiology block begins.

Chapter 8: Cell: The Unit of Life (pp. 85-103)

Every organism is built from cells or aggregates of cells, and cells vary in shape, size and function. Grouped by the presence or absence of a nucleus, they fall into prokaryotic and eukaryotic cells, and the chapter names the organelles each type carries.

1. What is a Cell? (p. 87)
2. Cell Theory (p. 87)
3. An Overview of Cell (p. 88)
4. Prokaryotic Cells (p. 89)
5. Eukaryotic Cells (p. 91)

The organelle survey runs from the Cell Membrane (p. 93) and Cell Wall (p. 94) through the Endomembrane System (p. 94), Mitochondria (p. 96), Plastids (p. 97), Ribosomes (p. 98), Cytoskeleton (p. 98) and Cilia and Flagella (p. 99).

It continues through Centrosome and Centrioles (p. 99) and the Nucleus (p. 100) to Microbodies (p. 102). At 19 pages, 18 named sections, 12 figures and 14 questions, this is the longest cell chapter in the book and the one that names every organelle later chapters assume.

Chapter 9: Biomolecules (pp. 104-119)

For all the bewildering diversity of organisms, their chemical composition and metabolic reactions turn out to be remarkably similar. The chapter moves from analysing composition, through metabolites and biomacromolecules, to proteins, polysaccharides, nucleic acids and the enzymes that speed up reactions.

1. How to Analyse Chemical Composition? (p. 104)
2. Primary and Secondary Metabolites (p. 108)
3. Biomacromolecules (p. 108)
4. Proteins (p. 109)
5. Polysaccharides (p. 110)
6. Nucleic Acids (p. 111)
7. Structure of Proteins (p. 111)
8. Enzymes (p. 112)

With 16 pages, 14 named sections, 5 figures and 11 questions, the enzyme activity graphs (Fig. 9.5, p. 116) are the most quoted page in the chapter.

Chapter 10: Cell Cycle and Cell Division (pp. 120-130)

By the cell theory, cells arise from pre-existing cells, and the process is cell division. The chapter follows one complete cell cycle, walks the stages of mitosis, then the two divisions of meiosis, and states the significance of each.

1. Cell Cycle (p. 120)
2. M Phase (p. 122)
3. Significance of Mitosis (p. 125)
4. Meiosis (p. 125)
5. Significance of Meiosis (p. 128)

Across 11 pages with 13 named sections, 4 figures and 16 exercise questions, this chapter carries the densest question load per page in the book — practise it rather than re-reading it.

Chapter 11: Photosynthesis in Higher Plants (pp. 131-152)

Green plants make their own food by photosynthesis: carbon dioxide enters through stomata and is used to build carbohydrate. The chapter runs from early experiments, through the light reaction and Calvin cycle, to the C4 pathway, photorespiration and the factors that limit the process.

1. What Do We Know? (p. 133)
2. Early Experiments (p. 134)
3. Where Does Photosynthesis Take Place? (p. 136)
4. How Many Types of Pigments Are Involved in Photosynthesis? (p. 137)
5. What is Light Reaction? (p. 138)
6. The Electron Transport (p. 138)
7. Where Are the ATP and NADPH Used? (p. 142)
8. The C4 Pathway (p. 145)
9. Photorespiration (p. 147)
10. Factors Affecting Photosynthesis (p. 149)

The book’s longest chapter — 22 pages, 19 named sections, 9 figures and only 9 questions — and the figures carry the content: the Z scheme (Fig. 11.5, p. 139), the Calvin cycle (Fig. 11.8, p. 144) and the Hatch and Slack pathway (Fig. 11.9, p. 146).

Chapter 12: Respiration in Plants (pp. 153-165)

Plants have no special organs for breathing; stomata and lenticels allow gaseous exchange, and nearly every living cell respires. The chapter tracks the pathways — glycolysis, fermentation, aerobic respiration and the electron transport system — then closes with the respiratory balance sheet and respiratory quotient.

1. Do Plants Breathe? (p. 154)
2. Glycolysis (p. 155)
3. Fermentation (p. 157)
4. Aerobic Respiration (p. 158)
5. The Respiratory Balance Sheet (p. 161)
6. Amphibolic Pathway (p. 162)
7. Respiratory Quotient (p. 163)

Across 13 pages, 9 named sections, 6 pathway figures and 12 questions, glycolysis (Fig. 12.1, p. 156) and the citric acid cycle (Fig. 12.3, p. 159) are the two figures worth reproducing from memory.

Chapter 13: Plant Growth and Development (pp. 166-180)

Growth is an irreversible increase in size, area, length or number of cells, and it is one of the most conspicuous events in any organism. The chapter covers where plants grow, how growth is measured, its phases and rates, and the plant growth regulators that control it.

1. Growth (p. 167)
2. Differentiation, Dedifferentiation and Redifferentiation (p. 172)
3. Development (p. 172)
4. Plant Growth Regulators (p. 174)

With 15 pages, 16 named sections, 11 figures and 10 questions, the growth curves (Figs. 13.4-13.6, pp. 169-170) and the auxin tip experiment (Fig. 13.10, p. 174) are the revision anchors.

Chapter 14: Breathing and Exchange of Gases (pp. 181-192)

Cells use oxygen for metabolism and produce carbon dioxide that must be cleared, so animals have evolved different respiratory mechanisms. In humans the chapter follows the respiratory organs, the mechanics of breathing, gas exchange, and the transport of oxygen and carbon dioxide in the blood.

1. Respiratory Organs (p. 183)
2. Mechanism of Breathing (p. 185)
3. Exchange of Gases (p. 187)
4. Transport of Gases (p. 189)
5. Regulation of Respiration (p. 190)
6. Disorders of Respiratory System (p. 190)

Across 12 pages, 10 named sections, 5 figures and 14 questions, the oxygen dissociation curve (Fig. 14.5, p. 189) is the graph that ties oxygen transport to the chapter’s questions.

Chapter 15: Body Fluids and Circulation (pp. 193-204)

Vertebrates circulate blood, a fluid connective tissue, to carry essentials to cells and wastes away from them. The chapter covers blood and its formed elements, lymph, the double circulation of the human heart, and disorders of the circulatory system.

1. Blood (p. 193)
2. Lymph (Tissue Fluid) (p. 197)
3. Circulatory Pathways (p. 197)
4. Double Circulation (p. 201)
5. Regulation of Cardiac Activity (p. 202)
6. Disorders of Circulatory System (p. 202)

With 12 pages, 13 named sections, 4 figures and 14 questions, the section of the human heart (Fig. 15.2, p. 198) and the circulation plan (Fig. 15.4, p. 202) are the two diagrams students are most often asked to draw.

Chapter 16: Excretory Products and Their Elimination (pp. 205-216)

Nitrogenous substances, ions, carbon dioxide and water accumulate in the body and must be eliminated; the nature of the nitrogenous waste depends on the organism. In humans the chapter moves from the excretory system to urine formation, the counter current mechanism, and the disorders of excretion.

1. Human Excretory System (p. 206)
2. Urine Formation (p. 208)
3. Function of the Tubules (p. 209)
4. Mechanism of Concentration of the Filtrate (p. 210)
5. Regulation of Kidney Function (p. 212)
6. Micturition (p. 212)
7. Role of Other Organs in Excretion (p. 213)
8. Disorders of the Excretory System (p. 213)

Across 12 pages, 8 named sections, 6 figures and 12 questions, the nephron (Fig. 16.3, p. 207) and the counter current diagram (Fig. 16.6, p. 211) are the core of any revision.

Chapter 17: Locomotion and Movement (pp. 217-229)

Movement is an essential feature of all living beings, from protoplasmic streaming and ciliary movement to the action of fins, limbs and wings. The chapter then concentrates on human muscle, the skeletal system, joints, and the disorders of each.

1. Types of Movement (p. 217)
2. Muscle (p. 218)
3. Skeletal System (p. 224)
4. Joints (p. 226)
5. Disorders of Muscular and Skeletal System (p. 227)

With 13 pages, 12 named sections, 10 figures and 10 questions, the sarcomere and sliding filament figures (Figs. 17.2-17.5, pp. 220-223) are the part students misdraw, so read the figures carefully.

Chapter 18: Neural Control and Coordination (pp. 230-238)

The neural system coordinates and integrates the functions, metabolism and homeostasis of all organs; neurons are its functional units. The chapter covers the human neural system, generation and conduction of a nerve impulse, synaptic transmission, and the regions of the brain.

1. Neural System (p. 231)
2. Human Neural System (p. 231)
3. Neuron as Structural and Functional Unit of Neural System (p. 231)
4. Central Neural System (p. 235)

Across 9 pages, 13 named sections, 4 figures and 10 questions, impulse conduction (Fig. 18.2, p. 233) and the synapse (Fig. 18.3, p. 234) are the mechanism the questions actually test.

Chapter 19: Chemical Coordination and Integration (pp. 239-252)

Special chemicals called hormones provide chemical coordination, integration and regulation in the human body. The chapter maps the endocrine system gland by gland — from hypothalamus and pituitary to the gonads — and closes with how hormones act on target cells.

1. Endocrine Glands and Hormones (p. 239)
2. Human Endocrine System (p. 240)
3. Hormones of Heart, Kidney and Gastrointestinal Tract (p. 247)
4. Mechanism of Hormone Action (p. 247)

The gland survey runs Hypothalamus (p. 240), Pituitary (p. 241), Pineal (p. 242), Thyroid (p. 242), Parathyroid (p. 243), Thymus (p. 243), Adrenal (p. 244), Pancreas (p. 245), Testis (p. 246) and Ovary (p. 246).

The final chapter runs 14 pages with 14 named sections, 5 figures and 9 questions, and the hormone action mechanism (Fig. 19.5, p. 249) is the diagram most reused in answers.

Chapter study pages

One page per chapter: each chapter below has its own study page carrying the full section list, figure index and exercise breakdown. The list shows the current status of each page.

How to use the 11th NCERT Biology book PDF for revision

The chapters build on each other, so the reading order matters more than most textbooks admit. This order works for this book:

1. Start with Chapters 1 and 2. Chapters 3 and 4 assume the classification vocabulary those two establish.
2. Read the cell block in order — Chapter 8, then 9, then 10. Structure first (cell), then molecules (biomolecules), then division (cell cycle).
3. Keep plant physiology in order — Chapter 11, then 12, then 13. Chapter 11 is the book’s longest at 22 pages, so give it the largest single sitting.
4. Human physiology runs Chapter 14 to 16, then 17 to 19. Breathing, circulation and excretion first; movement, neural control and hormones after.
5. Short on time? Practise by question load. Chapter 10 (16 questions in 11 pages) and Chapter 14 (14 questions) reward practice most. For diagram heavy revision, Chapter 4 runs 24 figures.

How to choose the right Class 11 NCERT Biology book PDF

Students are often handed a downloaded file and told it is “the” biology book. Check which edition it actually is:

• Current official edition. The 19 files in the download table are the English edition NCERT hosts on ncert.nic.in. The PDF is free; the printed book is sold at NCERT’s nominal price.
• Old NCERT requests. Older files, such as the 2006 edition, are separate PDFs. This page indexes and verifies only the current official edition, so confirm with your teacher which edition your school means.
• Hindi medium. This page covers the English edition only. The Hindi medium Class 11 Biology book is a separate NCERT publication and is not linked here.
• Reference books. The NCERT textbook is the base text for CBSE. A reference book supplements it — this page does not rank one.

Related resources

This listing is maintained for the 2026-27 academic session using the NCERT textbook information available to us. NCERT remains the authority for confirming the latest edition.

More from this directory of NCERT books:

• NCERT books directory — every class and subject this site indexes
• Class 11 hub — all the Class 11 textbooks in this directory
• Class 11 Chemistry NCERT textbook — the sibling science book to this one

Sources and data verification

• Where the figures come from: the counts, section titles and caption references on this page are read from the NCERT Class 11 Biology textbook editions on this page, from the official PDFs on ncert.nic.in.
• What this page covers: the 19 chapters of the English edition only. It is not the CBSE syllabus, and it does not cover Hindi or other medium editions.
• Academic session: this listing is maintained for the current academic session using the NCERT information available to us.
• Who settles what: NCERT settles textbooks, editions and PDFs; CBSE settles curriculum, syllabus and examinations. Textbook contents and the examinable syllabus are not always identical — check the current official syllabus before deciding what to leave out.

Reference: NCERT Class 11 Biology textbook, official edition on ncert.nic.in. Figure captions and section titles quoted from the textbook; page references are to the official PDF.

Frequently asked questions

How many chapters are in the Class 11 NCERT Biology book?

Nineteen chapters across 252 printed pages, grouped in this page’s five reading blocks: diversity (Ch 1-4), plant form (Ch 5-7), the cell (Ch 8-10), plant physiology (Ch 11-13) and human physiology (Ch 14-19). The download table above lists every chapter with its page range.

Is the 11th NCERT Biology PDF free and official?

Yes. The 19 PDFs linked above are NCERT’s own files, hosted free on ncert.nic.in. The printed book is a separate purchase.

Which chapter covers photosynthesis, the human heart and hormones?

Photosynthesis is Chapter 11 (pp. 131-152), the human heart is Chapter 15 (pp. 193-204), and hormones are Chapter 19 (pp. 239-252). Each chapter is linked in the download table above.

Where do the answers to the NCERT Class 11 Biology exercises live?

The exercises are printed at the end of each chapter in the PDF, and each chapter’s SUMMARY restates the main ideas of the chapter. This page indexes the textbook itself; it does not host a separate solutions file.

Should I use an old NCERT Biology Class 11 PDF instead of the current one?

Only if your teacher specifies it. This page links the current official English edition, so for any other file — an older edition or the Hindi medium book — confirm the edition with your teacher before relying on it.