Cells are adapted to preform specific functions. Which of the following terms refers to this capability?

A cell is the smallest basic unit of life, it is the fundamental unit of life that can replicate to give other cells. Tissues is a group or a collection of cells that have been specialized to perform a specific function. There are four main types of tissues in humans namely, connective tissues, epithelial tissues, muscle and nervous tissue. A group of tissues then forms an organ and then several organs forms an organ system