Answer
Thick filaments
Each thick filament contains 300 myosin molecules bundled so that their tails ( shafts) form the central part of the thick filament and their heads face outward at the end of each thick filament
Thin filaments ( 7-8 nm) are composed chiefly of fibrous actin. molecules.
These molecules present as bead-like chains of G-actin subunits. G-actin contains active sites that bind myosin heads during muscle contraction.
Work Step by Step
Two F-actin molecules interlace like a double chain ( or necklace) of pearls ( G-actin) : this forms the backbone of the thin filament.