The Repeating Unit of a Skeletal Muscle Fiber is The

Question

The repeating unit of a skeletal muscle fiber is the
A) sarcolemma.
B) sarcomere.
C) sarcoplasmic reticulum.
D) myofibril.
E) myofilament.

Accepted Answer

The repeating unit of a skeletal muscle fiber is the sarcomere, which is composed of myofilaments (actin and myosin) and gives the muscle its striated appearance. The sarcolemma is the cell membrane of the muscle fiber, the sarcoplasmic reticulum is the specialized endoplasmic reticulum of the muscle fiber that stores calcium ions, and the myofibril is a cylindrical organelle within the muscle fiber that is composed of sarcomeres.