Final answer:
Smooth and striated muscles share features like contractile proteins, but differ in their appearance and arrangement of cells.
Step-by-step explanation:
Smooth and striated muscles share common features such as having actin and myosin contractile proteins, and thick and thin filaments. However, they differ in their appearance and arrangement of cells. Smooth muscles are not striated because their cells are arranged in sheets, while striated muscles like skeletal and cardiac muscles have cells arranged in bundles or myofibrils, resulting in a striated appearance. Smooth muscle cells are spindle-shaped with a single nucleus and produce their own connective tissue.