Difference Between Unicellular And Multicellular Organisms
The difference between unicellular and multicellular organisms is majorly due to the difference in the composition, function, and arrangement of the cells. The unicellular organisms contain a single cell whereas the multicellular organisms contain multiple cells.
Unicellular organisms conciliate all the cellular activities by a single cell, while multicellular organisms carry out specific cell activities through a well-defined group of cells. The arrangement of cells is much simpler in unicellular organisms, whereas multicellular organisms found it complex to arrange cells.
Character Unicellular Organisms Multicellular Organisms
Cell A unicellular organism contains a single cell. A multicellular organism contains multiple cells.
Shape It is irregular in shape. The shape is well-defined.
Size It is small in size. It is comparatively large in size.
Nature Unicellular organisms are Microscopic. Multicellular organisms is Macroscopic.
Cell type It includes organisms having both prokaryotic and eukaryotic cell types. It includes organisms comprising only eukaryotic cell types.
Cell organization The cell organization is simple. The cell organization is complex.
Cell differentiation Generally absent, but unicellular yeasts may undergo differentiation Specialized cell differentiation occurs
Life span The life span is short. The life span is longer.
Evolution The oldest life forms evolved 3.8-4 billion years ago These evolved from the prokaryotes
Operational efficiency Operational efficiency is low. Operational efficiency is high.
Reproduction Reproduction occurs via budding and binary fission. Reproduction occurs via gamete fusion.
Regeneration ability Unicellular organisms show a greater tendency to regenerate. Multicellular organism shows low regeneration ability.
Examples Bacteria, Protozoans, Unicellular amoeba, etc. Humans, Animals, Plants, etc.