The difference is that unicellular organisms are made up of one cell, while multicellular are made up of many cells.
humans , cats ,dogs and all other oraganisms made up of more than one cells
No. Bacteria and some prokaryotes are unicellular. The more evolved organisms are multi-cellular.
Unicellular organisms can died, but often they reproduce by fissioning into two new cells. Since neither cell is considered the original, the old cell never really dies.
They are multi