The contractile unit of a skeletal muscle fiber is a(an)___.
A) myofibril
B) sarcomere
C) myosin filament
D) actin filament
E) Z line

Question

Quizplus · Accepted Answer

The sarcomere is the functional unit of a skeletal muscle fiber, consisting of actin and myosin filaments arranged in a specific pattern. It is responsible for muscle contraction. Myofibrils are the structures within muscle fibers that contain many sarcomeres. Myosin and actin filaments are the proteins that make up the sarcomere, but they alone do not constitute the contractile unit. Z lines are the boundaries of the sarcomere but not the contractile unit itself.

The Contractile Unit of a Skeletal Muscle Fiber Is A(an)___