| Unicellular Organisms |
Multicellular Organisms |
|---|
| Unicellular organisms are composed of a single cell |
Multicellular organisms are composed of more than one cell |
| Simple body organization |
Complex body organization |
| A single cell carries out all necessary life processes |
Multiple cells perform different functions |
| The total cell body is exposed to the environment |
Only the outer cells are exposed to the environment |
| Division of labour is at the organelle level |
Division of labour is at cellular, tissue, organs and organ system level |
| Includes both eukaryotes and prokaryotes |
Includes only eukaryotes |
| A lifespan of a unicellular organism is usually short |
Multicellular organisms have a comparatively longer lifespan |
| Injury to the cell leads to the death of the organism |
Injury to a cell does not cause the death of the multicellular organism |
| Asexual reproduction is predominant, however, sexual reproduction is also seen (conjugation) |
Reproduction happens sexually as well as asexually |
| Cell differentiation is absent |
Cell differentiation is present |
| They can be autotrophs or heterotrophs |
They include both autotrophs and heterotrophs |
| They are microscopic in nature |
Most are macroscopic in nature |
| Bacteria, amoeba, paramecium and yeast are examples of unicellular organisms |
Humans, animals, plants, birds and insects, are examples of multicellular organisms |
