Cell specialisation

• The cells in multicellular organisms are each specialised in different ways to carry out a particular role, by having more or less of a certain organelle dependent on the intended function.
• All cells in an organism are produced by mitotic division. They therefore all contain the same genes.
• Cell specialisation enables an organism to function efficiently.
• A tissue is a collection of cells that carries out a particular function. Examples of tissues include epithelial cells which form lining tissues.
• An organ is a combination of different types of tissues that are coordinated to carry out a variety of functions, although they usually have one major function. Examples of organs are the heart, lungs, stomach in animals. And in plants, the leaf, flower and roots.
• Organs work together as a single unit called an organ system. Examples of organ systems include the digestive system, respiratory system and nervous system.