Class 9 Science – Chapter 5: Cell (The Fundamental Unit of Life) Notes
1. What is a Cell?
Cell is the smallest unit of life
All living organisms are made of cells
Discovered by Robert Hooke (1665)
Living cell discovered by Leeuwenhoek
Cell Theory
• All organisms are made of cells
• Cell is basic unit of life
• New cells come from pre-existing cells
2. Types of Cells
Prokaryotic → No true nucleus (Bacteria)
Eukaryotic → True nucleus (Plants, animals)
Difference:
Prokaryotic → small, simple
Eukaryotic → large, complex
3. Plant Cell vs Animal Cell
Plant Cell
• Cell wall present
• Chloroplast present
• Large vacuole
• Fixed shape
Animal Cell
• No cell wall
• No chloroplast
• Small vacuole
• Irregular shape
4. Cell Organelles
(a) Cell Membrane
Outer covering of cell
Controls entry and exit of materials
1. What is a Cell?
Cell is the smallest unit of life
All living organisms are made of cells
Discovered by Robert Hooke (1665)
Living cell discovered by Leeuwenhoek
Cell Theory
• All organisms are made of cells
• Cell is basic unit of life
• New cells come from pre-existing cells
2. Types of Cells
Prokaryotic → No true nucleus (Bacteria)
Eukaryotic → True nucleus (Plants, animals)
Difference:
Prokaryotic → small, simple
Eukaryotic → large, complex
3. Plant Cell vs Animal Cell
Plant Cell
• Cell wall present
• Chloroplast present
• Large vacuole
• Fixed shape
Animal Cell
• No cell wall
• No chloroplast
• Small vacuole
• Irregular shape
4. Cell Organelles
(a) Cell Membrane
Outer covering of cell
Controls entry and exit of materials
