Unicellular and multicellular organisms
The cell is the functional and structural unit of every living being. According to the number of cells all the organisms are divided into
- Organism which are made up of single cell are called as Unicellular organisms.
- Organisms such as amoeba, Paramecium, euglena, bacteria, archae are unicellular. Some Protista and fungi are also unicellular.
- Living organism which we can see with naked eye are called as multicellular organisms.
- These organisms contain more than one cell and therefore they are called as multicellular organisms.
- All multicellular organisms begin their life as a single cell which is a fertilized egg.
- The fertilized egg cell multiplies and the number of cells increases as the organism develops.
- All the activities in the multicellular organism are performed by different types of specialized cells.
- For example, plants and humans are multicellular organism, as they are made up of many cells.
The organization in the multicellular organism from lower level is as follows
cell –tissues–organs–organ system–organism.