Explain what is meant by the term specialised cells.

Specialised cells refer to cells that have developed certain characteristics to perform specific functions. This process is known as cell differentiation. As the organism grows, cells differentiate to become specialised, thus enhancing the efficiency of the organism.

For example, red blood cells are specialised to carry oxygen through the bloodstream. They have a unique, biconcave shape that increases their surface area for oxygen absorption. They also lack a nucleus, which provides more space for carrying oxygen.

Another example is nerve cells (neurons), which are specialised to transmit electrical signals throughout the body. They have long extensions called axons that help in the transmission of these signals over long distances.

In plants, root hair cells are specialised for water absorption. They have a large surface area to increase the rate of absorption of water and minerals from the soil.

So, in summary, specialised cells are cells that have undergone changes to perform specific tasks more efficiently in the body of an organism.