An aggregation of cells having the same origin and performing a definite function is called a ___.
organ system
An aggregation of cells having the same origin and performing a definite function is called a tissue.In other words, a large mass of similar cells that make up a part of an organism and perform a specific function. The internal organs and connective structures (including bone and cartilage) of vertebrates and cambium, xylem and phloem in plants are made up of different types of tissue.