The cell is the basic functional unit of all known living organisms. The cell is the smallest unit of life that can replicate independently.
Cells group to form tissues. Tissues have a specialized functions. Examples of tissues include blood, muscle and bone.
Different tissues group to form organs. Examples of organs include stomach, liver, heart and brain.
Organs form organ systems which perform a particular function which maintains homeostasis and maintains normal health.
The digestive system is an example of an organ system. It is responsible for digesting and absorbing food. It consists of a number of organs including the stomach and intestines.
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