Cells
The cell is the basic unit of all living things.
- Cell theory states that all living things are made of cells, and cells come from other cells.
- Organelles each do a job — the nucleus controls the cell, mitochondria release energy.
- Cells organise into tissues → organs → systems, and materials move by diffusion and osmosis.
Diffusion moves particles from where they are crowded to where they are sparse, which is how cells take in what they need.