A living thing has multiple level of organisation. Each level of organisation has its own properties, which are not found in its constituents.
Examples of three tissues supporting the statements are
(i) Cardiac muscle tissue It is a contractile tissue present only in heart. Cell junctions fuse the plasma membrane of cardiac muscle cells and make them stick together. When one cell receives a signal to contract, its neighbours also starts to contract. It means a single cell cannot contract, while there are some fusion points, which allow the cells to contract as a unit.
(ii) Blood It is a fluid connective tissue. The individual components of blood, i.e., RBCs, WBCs
and platelets have different properties but as a unit they make the blood, a tissue serving many functions.
(iii) Bone It is a hard connective tissue that forms the framework of the body. The individual cells inside the hone do not have this property.