The cell to cell communication is performed by certain chemical signals in the multi-cellular organisms. The chemical signal is perceived by the cell with the help of receptor. The signalling molecule binds to receptor thereby generating a response. The signalling molecule can only bind to a specific receptor. For example, nerve growth factor can only bind with nerve growth receptors and insulin binds only with insulin receptor.
Thus, To receive and respond to a chemical signal, a cell must have a <u>receptor</u> for that chemical.
