Stem cell
The human body is made up of different kinds of specialised cells such as muscle cells, nerve cells, fat cells and skin cells. All specialised cells originate from stem cells. A stem cell is a cell that is not yet specialised, and specialises into a specific cell type. Stem cells can be further separated into categories depending on whether they have started the specialisation process, for example haematopoietic stem cells are cells which can give rise to all the different haematopoietic cells.