difference between unicellular and multicellular organism?

Unicellular organism : Body is made up of single cell Multicellular organism : Body is made up of numerous cells Unicellular organism : Division of labour is at the organelle level. It gives a low level of operational efficiency Multicellular organism : Division of labour may be at cellular, tissue, organ and organ system level. It gives high degree of operational efficiency Unicellular organism : A single cell carries out all the life processes Multicellular organism : Different cells are specialized to perform different functions Unicellular organism : The cell body is exposed to the environment on all sides Multicellular organism : Only outer cells are specialized to face the environment. Inner cells are devoted to other functions Unicellular organism : An injury of the cells can cause death of the organism. Multicellular organism : Injury or death of some cells does not affect the organisms as the same can be replaced by new one. Unicellular organism : A cell body cannot attain a large size because of the limit imposed by surface area to volume ratio Multicellular organism : A multicellular body can attain a large size increasing the number of small cells Unicellular organism : Lifespan is short due to heavy load of work Multicellular organism : Lifespan is long due to limited load of work for each cell type Unicellular organism : Power of division is not lost Multicellular organism : Certain specialized cells lose power of division Unicellular organism : A well-marked capacity of regeneration is present Multicellular organism : The capacity of regeneration decreases with increasing specialization Unicellular organism : The cell has the same role for itself and the organism Multicellular organism : Cells have a double role. One for themselves and other for the organism read less

In unicellular organism, body is made up of single cell and carries out all the life processes and lifespan is short due to heavy load of work while in multi-cellular organism, body is made up of multiple cells and different cells are specialized to perform different functions and Lifespan is long due to limited load of work for each cell type. read less