What structural feature distinguishes skeletal muscle from other muscle types?

The distinguishing feature of skeletal muscle is its striated appearance. This striation is due to the highly organized arrangement of myofilaments (actin and myosin) within the muscle fibers, creating a banded pattern that is characteristic of skeletal muscle. Each fiber in skeletal muscle is multinucleated, which contributes to its distinct structure and function but does not define it uniquely compared to cardiac or smooth muscle.

In contrast, cardiac muscle, while also striated, is involuntary and has a single nucleus per cell. Smooth muscle cells have a non-striated, smooth texture and are also involuntary, further differentiating them from skeletal muscle. Thus, striation serves as the primary structural identifier of skeletal muscle among the three muscle types, making it the correct answer.