TISSUE Tissue is a biological structure made up of cells of the same type. Cells of the same phenotype(i.e, same genes expressed) An aggregation of morphologically similar cells and associated extracellular matrix acting together to perform one or more specific functions in the body. There are four basic types of tissue: muscle, nerve, epithelia, and connective. An organ is a structure made up of 2 or more tissues.TISSUE • Tissue is a biological structure made up of cells is a biological structure made up of cells of the same type. of the same type. – – Cells of the same phenotype ( Cells of the same phenotype (i.e., same genes ., same genes expressed). expressed). – – An aggregation of morphologically similar cells and An aggregation of morphologically similar cells and associated extracellular matrix acting together to associated extracellular matrix acting together to perform one or more specific functions in the body. perform one or more specific functions in the body. – – There are four basic types of tissue: muscle, nerve, There are four basic types of tissue: muscle, nerve, epithelia, and connective. epithelia, and connective. – – An organ is a structure made up of 2 or more tissues. is a structure made up of 2 or more tissues