Answer:
Thin and Thick filament.
Step-by-step explanation:
The actin and myosin are the important proteins of the muscles. These proteins shows striations of the skeletal and cardiac muscle, when observed under the microscope.
Actin protein is the major constituent of the thin filament. Thin filament is 7 nm in diameter and made of globular proteins. Myosin protein is the major constituent of the thin filament. This filament is 15 nm in diameter.
Thus, the actin comprise of thick filament and myosin comprise of thin filament.