How Does Cell Specialisation Work?

Cell specialisation works when an unspecialised cell differentiates, developing particular sub-cellular structures that allow it to perform a specific function. This creates different cell types for tissues, organs and organ systems.

What is differentiation?

Differentiation is the process by which a cell changes to become specialised. As an organism develops, cells acquire structures suited to particular jobs.

Most animal cells differentiate early in development. In mature animals, cell division is mainly used for growth, repair and replacement. Many plant cells retain the ability to differentiate throughout life.

Examples of specialised cells

A specialised cell’s structure is related to its function:

• Sperm cells have a tail for movement and many mitochondria to transfer the energy needed to swim towards an egg.
• Nerve cells are long, allowing electrical impulses to travel over large distances.
• Muscle cells contain structures that contract and many mitochondria for energy transfer.
• Root hair cells have a long projection that provides a large surface area for absorbing water and mineral ions.
• Xylem cells form hollow tubes that transport water and mineral ions through a plant.

Worked example

Question: How is a root hair cell specialised for its function?

Answer: Its long projection gives it a large surface area, increasing water uptake by osmosis and mineral ion uptake by active transport.

Stem cells and specialisation

A stem cell is undifferentiated. It can divide and differentiate into specialised cell types. Embryonic stem cells can form most human cell types. Adult bone marrow stem cells can form blood cells. Plant meristem cells can form any plant cell throughout life.

Exam tip

Do not simply name a feature. Link it to its function, for example: “many mitochondria transfer more energy for movement.”

Scope assumption: AQA GCSE Biology separate science; both Foundation and Higher tiers. This topic is shared with Combined Science.