Cell Specialisation and Differentiation — AQA GCSE Biology
Cells become specialised to carry out particular jobs. The process of becoming specialised is called differentiation.
Differentiation
- As an organism develops, cells differentiate to form different types with structures suited to their function.
- In animals, most cells differentiate at an early stage, and cell division is then mainly for repair and replacement.
- In plants, many cells keep the ability to differentiate throughout life.
A cell that has differentiated gains new sub-cellular structures suited to its role.
Examples of specialised cells
| Cell | Adaptation | Function |
|---|---|---|
| Sperm cell | tail (flagellum), many mitochondria, enzymes in the head | swims to and fertilises the egg |
| Nerve cell | long, thin, with branched connections | carries electrical impulses |
| Muscle cell | contains protein fibres that contract | movement |
| Root hair cell | large surface area, thin wall | absorbs water and mineral ions |
| Xylem cell | hollow, no end walls, strengthened with lignin | transports water |
| Phloem cell | sieve plates, companion cells | transports dissolved sugars |
Exam tips
- Define differentiation as the process of becoming specialised.
- For any specialised cell, link its structure to its function (e.g. root hair cell → large surface area → more absorption).
- Remember plant cells keep the ability to differentiate; most animal cells lose it.