Question

The functional units of skeletal muscle that allow it shorten are:

tendons
fascicles
sarcomeres
perimysium

Answer 1

Answer: sarcomere



The sarcomere is the smallest functional unit of a skeletal muscle fiber and is a highly organized arrangement of contractile, regulatory, and structural proteins. It is the shortening of these individual sarcomeres that lead to the contraction of individual skeletal muscle fibers (and ultimately the whole muscle).

Answer 2

The functional unit of skeletal muscle that allows it to shorten is the sarcomere.

Step-by-step explanation:

A sarcomere is the smallest contractile unit of a muscle fiber and is composed of overlapping thick and thin filaments made of protein. When a muscle fiber receives a signal to contract, the thick and thin filaments slide past each other, causing the sarcomere to shorten and the muscle to contract. Fascicles are bundles of muscle fibers, perimysium is the connective tissue that surrounds fascicles, and tendons are the connective tissue that attach muscle to bone and allow for the transmission of force from muscle to bone. While important for the overall function of skeletal muscle, these structures do not directly contribute to the ability of skeletal muscle to shorten.