Organisms of kingdom fungi have multicellular or loose tissue. In organisms of kingdom Plantae, the body organisation is tissue or organ grade whereas body organisation in kingdom Animalia is tissue or organ or organ system. In unicellular organisms, all functions like digestion, respiration and reproduction are performed by a single cell. In the complex body of multicellular animals, the same basic functions are carried out by different groups of cells in a well-organised manner. The body of a simple organism like Hydra is made of different types of cells and the number of cells in each type can be in thousands. The human body is composed of billions of cells to perform various functions. In multicellular organisms of fungi, plant and animal kingdoms, a group of similar cells perform a specific function. Such an organisation is called tissue.