Muscle cells contract and relax for movement, nerve cells transmit messages, and blood cells transport oxygen, food, hormones, and waste materials.

Specialized cells in multicellular organisms efficiently perform specific functions, allowing the organism as a whole to carry out complex tasks more effectively.

Amoeba is an example of a unicellular organism. It carries out movement, intake of food, gaseous exchange, and excretion within a single cell.

Unicellular organisms perform all basic functions within a single cell, whereas multicellular organisms distribute these functions among millions of specialized cells.