Cells are adapted to the roles they fill in living things. These adaptations or specialisations take on different forms.
In organisms, such as humans, we need many different cell types to function properly. It saves the body energy and resources by getting cells to carry out a particular function.
You can be asked to explain how different cells are adapted to fill their roles in the body.
When explaining specialisation, you need to look at the information they present you with and use it to explain how the structure of a cell relates to its function in the organism.
Some specialisations and structures have similar roles no matter what the organism.
Root Hair Cell
Long projections from a cell are usually for increased surface area. This gives the cell more space with which to absorb important materials.
Root hair cells in plants and villi in the small intestine both have this adaptation as it means they can absorb more material more effectively than cells without these projections.