Examples of Specialised Cells

These are examples of specialised cells and how they have been modified for specific functions.

1. RED BLOOD CELL

The red blood cell contains a red pigment called haemoglobin. Haemoglobin transports oxygen from the lungs to all parts of the body.

The red blood cell has no nucleus, enabling it to carry more haemoglobin and hence more oxygen.

The red blood cell has a circular biconcave shape. This increases the surface area to volume ratio of the cell. As a result, oxygen can diffuse into and out of the entire cell at a faster rate.


2. XYLEM VESSEL

Xylem vessels are long hollow tubes formed out of xylem cells laid end to end. They conduct water and mineral salts from the roots up to the stem and leaves. Xylem vessels do not have cross walls or protoplasm. This enables water to move easily through the central space or lumen.

A substance called lignin is deposited on the walls of xylem vessels. Lignin strengthens the walls and prevents the vessels from collapsing. When bundled together, the xylem vessels (also called 'wood') provide mechanical support to the plant.


3. THE ROOT HAIR CELL

The root hair cell is long and narrow. This increases the surface area to volume ratio of the cell. As a result, water and mineral salts can be efficiently absorbed from the soil.


sources:
Biology Matters chapter 2: cells
http://en.wikipedia.org/wiki/
http://www.bbc.co.uk/

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