Page 1: Introduction

All living organisms are made of cells.

Cell is the basic structural and functional unit of life.

Unicellular organisms perform all life processes in one cell.

Multicellular have division of labour.

Page 2: Discovery of Cell

Robert Hooke (1665): observed cork cells under microscope — coined term "cell".

Anton van Leeuwenhoek: observed living cells.

Improved microscopes led to detailed study.

Page 3: Cell Theory

Schleiden (plants), Schwann (animals), Virchow (new cells from old).

Page 4: Types of Cells

• Prokaryotic: No well-defined nucleus, no membrane-bound organelles (e.g., bacteria, blue-green algae).
• Eukaryotic: Well-defined nucleus, membrane-bound organelles (plants, animals, fungi, protists).

Page 5: Shape and Size of Cells

Varied shapes: spherical (RBC), elongated (nerve), branched, disc-shaped.

Size: 0.1 μm (bacteria) to 10-100 μm (most cells), ostrich egg largest isolated cell.

Page 6: Plasma Membrane

Osmosis: movement of water across semi-permeable membrane.

Page 7: Cell Wall (Plant Cells)

Page 8: Nucleus

Page 9: Cytoplasm

Jelly-like substance between plasma membrane and nucleus.

Contains organelles.

Site of many metabolic reactions.

Page 10: Endoplasmic Reticulum (ER)

• Rough ER: ribosomes attached → protein synthesis
• Smooth ER: lipid synthesis, detoxification

Transport system.

Page 11: Golgi Apparatus

Packaging and dispatch unit.

Modifies, sorts, packs proteins.

Forms lysosomes.

Page 12: Lysosomes

Page 13: Mitochondria

Double membrane, own DNA.

Page 14: Plastids (Plant Cells)

• Chloroplasts: photosynthesis (chlorophyll)
• Chromoplasts: colour (flowers/fruits)
• Leucoplasts: storage (starch, oil, protein)

Page 15: Vacuoles

• Plant: large central, storage, turgor pressure
• Animal: small, numerous

Store food, waste, maintain turgidity.

Page 16: Plant vs Animal Cell Comparison

Page 17: Practice Questions - Easy (1-10)

1. Who discovered cell?
2. Cell theory point 3.
3. Powerhouse of cell.
4. Suicide bags.
5. Cell wall material.
6. Largest cell.
7. Plasma membrane function.
8. Chloroplast function.
9. Nucleus called control centre because?
10. Difference prokaryotic vs eukaryotic.

Page 18: Practice Questions - Medium (11-20)

11. List 5 plant cell organelles absent in animal.
12. Functions of Golgi apparatus.
13. Why lysosomes called suicide bags?
14. Explain osmosis with example.
15. Role of mitochondria.
16. Difference rough vs smooth ER.
17. Why plant cells have large vacuole?
18. Chromoplast function.
19. Nucleolus function.
20. Cell wall advantage.

Page 19: Practice Questions - Hard (21-30)

21. Draw labelled plant cell description.
22. Compare plant and animal cell table.
23. Explain cell theory importance.
24. Functions of all organelles.
25. Why plasma membrane selective.
26. Real-life analogy for organelles.
27. Prokaryotic cell diagram features.
28. Cell as factory analogy.
29. Division of labour in multicellular.
30. Historical discovery timeline.

Page 20: NCERT Exercise Types

Differences, functions, labelled diagrams, reasoning.

Page 21: Common Mistakes

• Forgetting plastids in plant
• Confusing lysosome and vacuole
• Wrong cell theory points
• Missing centrosome in animal
• Wrong organelle functions

Page 22: Exam Tips

• Draw neat labelled diagrams
• Tabular comparison for differences
• List functions clearly
• Memorise cell theory exactly
• Use bullet points

Page 23: Quick Revision Sheet

All organelles, functions, differences.

Page 24: Organelle Functions Table

Comprehensive table.

Page 25: Final Motivation

Chapter 5 complete! Cell is the most important Biology chapter.

Master diagrams and functions.

Board Buddy Biology launched 🦖

Page 26: Diagram Descriptions

Plant and animal cell labelled features.