Every living thing is built from cells — the smallest units that can carry out life's work. Tap or click any part of the diagram below to learn what it does, in plain language, with an everyday comparison to help it stick.
A cell is the smallest structure that is still considered "alive." Some organisms — like bacteria — are just one single cell. Others, like you, are made of trillions of cells working together, each one specialised for a job: carrying oxygen, sending nerve signals, fighting infection, or holding your skin together.
Inside every cell are tiny structures called organelles — literally "little organs." Each organelle has its own job, the same way your heart, lungs, and stomach each do something different for your body.
FIG. 1A — GENERALISED ANIMAL CELL (CROSS SECTION)
FIG. 1B — GENERALISED PLANT CELL (CROSS SECTION)
Prefer reading over clicking? Every part of the cell is listed below — this list updates to match the cell type you have selected above.
| Feature | Animal cell | Plant cell |
|---|---|---|
| Cell wall | ✕ Absent | ✓ Present (rigid, cellulose) |
| Cell (plasma) membrane | ✓ Present | ✓ Present |
| Nucleus | ✓ Present | ✓ Present |
| Mitochondria | ✓ Present | ✓ Present |
| Chloroplasts | ✕ Absent | ✓ Present (site of photosynthesis) |
| Vacuole | Several, small | One large central vacuole |
| Lysosomes | ✓ Common | Rare / less prominent |
| Typical shape | Round / irregular | Fixed, rectangular |
Think of a cell as a tiny factory with a boss (nucleus), power plants (mitochondria), and a delivery team (Golgi & ER). Just explore the diagram and read one part at a time.
Focus on the animal-vs-plant table above — exams love asking which structures are unique to plant cells (cell wall, chloroplast, large vacuole).
Trace how a protein is made: Ribosome → Rough ER → Golgi apparatus → transported out through the cell membrane. That's the cell's whole "shipping" process.