Talk about the sarcomere.

It results from the orderly and parallel arrangement of fine and thick myofilaments along the myofibrillar axis. It comprises an A band with two half I bands from either sides. It is the smallest structural and functional unit of the muscle cell called contraction unit. Myofibrils are a sequence of sarcomeres in a cell, sarcomeres of all myofibrils are located at the same level which explains the transverse striation of the muscle cell.