All organisms are made up of cells .Cells organize in following ways.
- Unicellular Organisation: In it only one cell makes the life of an organism. All the life activities are carried out by the only cell. e.g. Amoeba, Paramecium, and Euglena etc.
- Colonial Cellular Organization: In it many unicellular organisms that shows colonial organization.
- Multicellular Organization: In it cells are organized (grouped) in the form of tissues, organs and organ systems. g. Frog and mustard .
Examples of Multi cellular Organizations
I- MUSTARD PLANT:
Its scientific name is Brassica campestris. It is sown in winter and it makes seeds at the end of winter. Its body is used as vegetable and its seeds are used for extracting oil.
Its Root, stem, branches and leaves are the vegetative organs, which do not take part in the sexual reproduction. Flowers are the reproductive organ of the plant because they take part in sexual reproduction and produce fruits and seeds.
Its scientific name is Rana tigrina. Its body is made of organ systems and each organ system has related organs.
All the organs are made of specific tissues e.g. epithelial, glandular, muscular, nervous etc.