Differentiate between Organism and organ system

Cells are organized into tissues (epithelium, connective tissue, muscle tissue, and nervous tissue ), tissues are organized into organs (liver, kidney etc), organs are organized into organ systems ( digestive system , excretory system etc.) and organ systems are organized into the organism (human body, animal body).

The organ system is a level of organisation in which the organs join together to form a higher group of organisation i.e. organism. 

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