Principles of Organisation (AQA GCSE Biology)

Organisation: Principles

Multicellular organisms have many levels of organisation

• Cells are the basic building blocks of all living organisms

• Unicellular organisms are made from one cell, whereas multicellular organisms are made up of collections of cells

• In complex multicellular organisms, cells are specialised to carry out particular functions. These specialised cells form tissues, which form organs in organ systems

• In humans, the digestive system (provides the body with nutrients) and the respiratory system (provides the body with oxygen and removes carbon dioxide) are examples of organ systems that provide dissolved materials that need to be moved quickly around the body in the blood by the circulatory system

Organisation table