What are the advantages of multicellularity?
Multicellular organization increases the efficiency of the organism in the following ways follows :

1. Avoids duplication of work : Only certain cells perform a specific function. Thus, all cells do not have to perform the same function and there is no waste of energy on duplication of work.

2. Increases chances of survival : Death of a few cells does not affect a multicellular organism. The function is taken by new cells of the same lineage.

3. Makes specialized units highly effective: Diffrent cells perform different function. Cells performing similar functions are grouped into tissue which carry out specific function. 

4. Long life : Greater efficiency of the cells, because of division of labour, makes multicellular organisms to live longer.