A cell is the basic unit of life.
All living things — plants, animals, bacteria, and humans — are made up of cells.
πΉ Some organisms (like bacteria) are made of one single cell (unicellular).
πΉ Others (like humans) are made of trillions of cells (multicellular).
𧬠Main Types of Cells
| Type | Description | Example |
|---|---|---|
| Prokaryotic | Simple, no nucleus | Bacteria |
| Eukaryotic | Complex, has a nucleus | Plant, animal cells |
𧱠Basic Parts of a Cell (Eukaryotic)
| Part / Organelle | Function |
|---|---|
| Cell Membrane | Controls what enters and leaves the cell |
| Cytoplasm | Jelly-like fluid where organelles are suspended |
| Nucleus | The “brain” of the cell; contains DNA |
| Mitochondria | The “powerhouse”; produces energy (ATP) |
| Ribosomes | Make proteins |
| Endoplasmic Reticulum (ER) | Transports materials inside the cell |
| Golgi Apparatus | Packages and ships proteins |
| Lysosomes | Break down waste (mostly in animal cells) |
| Chloroplasts | Photosynthesis (only in plant cells) |
| Cell Wall | Gives structure and support (only in plant cells) |
| Vacuole | Stores water, food, and waste (large in plants) |
π± Differences Between Plant and Animal Cells
| Feature | Plant Cell | Animal Cell |
|---|---|---|
| Cell wall | β Present | β Absent |
| Chloroplasts | β Present | β Absent |
| Shape | Usually rectangular | Usually round |
| Vacuole | One large | Many small |
π What Do Cells Do?
Cells:
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π§ Control body functions
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πͺ Help in growth and repair
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π¦ Fight infections (white blood cells)
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πΏ Perform photosynthesis in plants
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β‘ Create energy from food (cell respiration)
π¬ Fun Facts About Cells
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The average human body has about 37 trillion cells!
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The largest cell is the ostrich egg.
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Some bacteria can live in boiling water or frozen ice — still as single cells.
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Red blood cells have no nucleus!
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The DNA inside a single human cell is about 2 meters long when stretched out.